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The salted egg yolks supplemented with clove extract are compared with the non‐supplemented group, and subsequently the lipidomics profiles are characterized and identified by UPLC‐QE‐MS/MS in positive and negative ion modes respectively. A total of 315 lipids are detected in the control group and the clove extract treated group. In the positive ion mode, the 10 subclasses of glycerolipids in the treated samples are significantly different (p < 0.05). The lipid types with most varied compositions are triglyceride and ceramides, followed by CerG1 (glucosylceramide), LPE (lyso‐phosphatidylethanolamine), diglyceride, and monosialodihexosyl ganglioside. In the negative ion mode, the authors identified 35 subclasses which are significantly different (p < 0.05), that include glycerolphospholipids, glycosphingolipids, and neutralglycosphingolipid. The lipid types with most varied compositions in negative mode are PE (phosphatidylethanolamine), followed by PC (phosphatidylcholine), LPC (lyso‐phosphatidylcholine), and GM3 (monosialo‐dihexosyl ganglioside). The contents of phosphatidylcholine, lyso‐phosphatidylcholine, phosphatidylethanolamine, and monosialo‐dihexosyl ganglioside in egg yolks treated with 0.5% (w/v) clove are significantly higher than those in the control group (p < 0.05), in which phosphatidylcholine and phosphatidylethanolamine are the main components of glycerolphospholipid. Practical Application : The lipidomics analyses of the salted egg yolk added with and without clove extract are compared to reveal the beneficial effect of clove extracts on the lipid profiles, and further exploring the types and relative content of the lipid components. A total of 315 lipids are detected in all samples. In the positive ion mode, the 10 subclasses of glycerolipids are found to be significantly different in the treated samples. In the negative ion mode, the lipid content of 35 subclasses are significantly different. From the nutrition fact value, salted duck egg enriched with clove extract can serve as one of the alternative egg products rich in essential lipids. [ABSTRACT FROM AUTHOR]

Abstract A series of different eggshell membrane (ESM) and chitosan (CS) blend films (ESM/CS) were prepared for wound-care dressing. The appearance, transparency and microstructure of the films were characterized. Several wound care-related properties such as the film integrity in solution, pH, protein (BSA) and wound fluid absorption capacity as well as the antibacterial property of ESM/CS films were evaluated. The blend films were more stable than CS film after 95 h of incubation in solution. The integrity of the blend films improved significantly at the cost of a small insignificant decrease in wound fluid absorption capacity. Besides, the blend films provided an acidic environment (pH = 5.86) for wound healing. The swelling properties of ESM contributed significantly to the increase of BSA absorption capacity of the blend films (from 46.57 mg/g of CS film to 61.07 mg/g of blend film) and helped absorb more nutrients to promote the proliferation and migration of fibroblasts. Addition of CS to ESM also enhanced the antibacterial activity of the films significantly. The results indicated that the EMS/CS blend films with 0.01 g ESM/mL CS solution showed the highest high potential to be used as a wound-care dressing for humans as well as animals. Highlights • We successfully prepared a new type of blend films with an outstanding wound-care properties. • The wound healing dressing of the blend film composed of chitosan and eggshell membrane was prepared for the first time. • Several wound care-related properties were improved with the incorporation of ESM and glycerol into chitosan film. [ABSTRACT FROM AUTHOR]

An efficient one-step grafting approach was developed to modify ovalbumin (OVA) by phosphorylation through selective reaction with the hydroxyl group of Ser and Thr residues present in OVA. The site-specific phosphorylated conjugates were characterized by Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF/MS) and the results indicated that the Ser residue could be more readily phosphorylated, and the typical phosphopeptides 264 LTEWTSSNVMEER 276 and 340 EVVGSAEAGVDAASVSEEFR 359 demonstrated the formation of monophosphoester. Moreover, 13 C NMR analysis showed that the βCH 2 of Ser acted as a hydroxyl donor to react with sodium tripolyphosphate (STPP), and the conjugates with variable phosphorylation sites could improve the weak network and the resulting poor mechanical properties of ovalbumin-based hydrogels. Furthermore, small-amplitude oscillatory measurements, creep recovery tests and texture profile analysis of hardness and stickiness indicated that phosphorylation can strengthen the intermolecular cross-linking of protein molecules and produce significant influence on the rheological behavior and texture properties, suggesting that a suitable conjugation site is essential for the best gelation properties at a different pH. The integrated results indicate that phosphorylation change significantly modify the viscoelastic and mechanical properties of OVA-based hydrogels by changing molecular dynamics upon heating. [ABSTRACT FROM AUTHOR]

To improve the interfacial properties, a phosphorylation modification of OVA was performed through dry-heating at three different pH values (5.0, 7.0 and 9.0) in the presence of sodium tripolyphosphate. X-ray photoelectron and Raman spectroscopies confirmed that phosphate groups were successfully grafted onto the ovalbumin backbone through covalent interaction to form O P bond. Additionally, 23, 21 and 18 phosphorylation sites were identified in the OVA that had been phosphorylated at pH 5.0, 7.0 and 9.0 (P-OVA5, P-OVA7 and P-OVA9) respectively by MALDI-TOF mass spectroscopy. More phosphorylated peptides and possible phosphorylation sites were found here than in previous studies with the reaction time reduced to 12 h. As a result, the iso-electric point (pI) of P-OVA shifted to lower pH, improving the stability of the P-OVA-included system over a wider pH range. The dynamic interfacial tension, which depends on the phosphorylation-induced conformational change, was explored by Fourier-transform Raman and circular dichroism spectroscopies, and the equilibrium interfacial tension decreased from 17.359 mNm −1 for natural OVA (N-OVA) to 15.969 mNm −1 for P-OVA9. Furthermore, P-OVA was applied to O/W emulsions, resulting in a narrower size distribution with a smaller particle size in P-OVA-stabilized emulsions than in N-OVA-stabilized emulsions. The increase rate of mean particle diameter after 60-min storage decreased from 72.37% for N-OVA to 7.97% for P-OVA5, implying a significant improvement of emulsion stability by preventing aggregation and coalescence. The results from this work demonstrated that the natural biopolymer can be applied to O/W emulsions by enhancing interfacial properties with phosphorylation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Acylation of OVA significantly improved the gel properties of hydrogels. • Acylation modification effectively promoted the formation of network structures in OVA hydrogels. • Acylation modification effectively enhanced hydrophobic interactions during thermal gelation. • Acylated OVA hydrogels exhibited a delayed drug release of curcumin. In this paper, the effects of acylation modification on the gel behavior of ovalbumin (OVA) under heating induction have been investigated. From the obtained results, the acylated OVA hydrogels exhibited superior gelation properties than the native OVA hydrogels (NOVA-G) in terms of light transmission, gel hardness, resilience and water holding capacity. SEM revealed acylation modifications effectively promoted the formation of uniform and dense network structure of OVA hydrogels. The main intermolecular forces of the acylation-modified OVA hydrogels were hydrophobic interactions and hydrogen bonding. FTIR showed that acylation modifications caused 26.2% decrease in α-helix and 59.2% increase in β-sheet content compared to NOVA-G. Furthermore, in-vitro release experiments showed that the release rate of curcumin from acylated OVA hydrogels was significantly delayed. Moreover, the above results have shown that acylation modifications can be considered as an effective method to improve the gelation as well as drug release properties of protein hydrogels. [ABSTRACT FROM AUTHOR]

Ovomucin has been considered to contribute a lot to the excellent functional properties of egg white. This work focused on investigating the effects of pH and protein concentration on foaming and emulsifying properties of ovomucin to evaluate the proper use of this egg protein as a functional food ingredient, and to clarify its contribution to the functional properties of egg white under different pH conditions. Protein solubility and surface hydrophobicity were measured through the pH ranged from 2.3 to 11.0. Alkali treatment gave ovomucin improved emulsification properties, which were correlated well with the surface hydrophobicity ( r≥ 0.89, P < 0.01). Although ovomucin showed lower foaming capacity in acid and neutral solution, enhanced foaming stability was observed with weak acid-treated ovomucin (pH 5 to 6) compared to native ovomucin. These results demonstrated that acid and alkali treatment, which leads to partial unfolding of ovomucin can improve functional properties of ovomucin, with the greatest improvement for emulsification properties being from the alkali treatment and for foaming stability being from weak acid treatment. These results are helpful to produce unfolding ovomucin suitable for wide range of applications in food industry, and to provide useful information on the proper use of egg white in different food systems. Practical Application: Ovomucin plays a critical functional role in egg white products. However, it is typically insoluble in distilled water or common salt solutions, which has thus limited its commercial applications. Alkaline treatment resulted in gradual increase in solubility, which markedly enhanced the emulsifying properties, on the other hand foaming stability of ovomucin can be promoted by weak acid treatment. The results of this work help to produce unfolding ovomucin suitable for wide range of applications in food industry, and to provide useful information on the proper use of egg white in different food systems. [ABSTRACT FROM AUTHOR]

Abstract: Avian egg albumen participates in embryonic development by providing essential nutrients as well as antimicrobial protection. Although various biological functions of egg white proteins were suggested during embryogenesis, global changes of these proteins under incubation conditions remained uninvestigated. This study presents a proteomic analysis on the change of egg white proteins during the first week of embryonic development. By using 2-DE, together with MALDI-TOF MS/MS, thirty protein spots representing eight proteins were identified showing significant changes in abundance during incubation. An accelerating degradation of ovalbumin was observed in a wide range of molecular weight. In addition, four protein complexes were predicted according to the detected molecular weight increase. Among these speculated protein complexes, an ovalbumin spot coupled with RNA-binding protein was detected. The absence of these protein complexes before incubation, followed by the constant increase in abundance during incubation indicates conceivable pivotal roles in embryonic development. To better understand the function of the proteins identified in this study, discrepancies of egg white protein changes between fertilized and unfertilized chicken eggs were additionally demonstrated. These findings will provide insight into the embryogenesis process to improve our knowledge of egg white proteins in regulating and supporting early embryonic development. [Copyright &y& Elsevier]

The antimicrobial activity of egg albumen has been widely documented. However, the changes in the chemical nature and antimicrobial activity of egg albumen and the way it controls bacteria during the incubation period have not up to now been understood. The purpose of the present investigation was to analyze the antimicrobial potential of egg albumen during early incubation stages (0-5 days). The changes in ovotransferrin and lysozyme content in egg albumen were quantified via high performance liquid chromatography (HPLC). The results showed that the increase in concentration of ovotransferrin in egg albumen was closely related to the time of incubation, but that of lysozyme remained substantially unchanged and was very similar to that of the non-incubated eggs. The iron ion binding capacity and specific lysozyme activity of the egg albumen during early stages of incubation was also investigated. The changes occurring in egg albumen during early incubation could influence the growth of Salmonella Enteritidis. Very little difference was observed in the virulence response of Salmonella Enteritidis to egg albumen collected at different incubation periods by using the expression of hilA gene as an indicator. Since the first few days of incubation are likely to place heavy demands on the immune capacities of the egg, due to the defenceless immune system of the developing embryo, the changes in antimicrobial activity in egg albumen widen our understanding of the innate immune mechanism of the fertilized egg during its early embryonic development. [ABSTRACT FROM AUTHOR]

Abstract: Knowing the adsorption behavior of target proteins on biofunctional magnetic nanoparticles is of great importance for the separation and purification of proteins. Adsorption behaviors of avidin on biofunctional magnetic nanoparticles binding to iminobiotin were investigated under different conditions of temperature, pH, ionic strength, and feed avidin concentration. Biofunctionalization of the non-functional nanoparticles was performed, coupled with iminobiotin. Characterization of the particles was carried out using transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The results showed the avidin adsorption behaviors were mainly dependent on affinity interaction between avidin and iminobiotin coupled with the nanoparticles, which exhibited temperature, pH, ionic strength, and feed avidin concentration sensitivity. Maximum avidin adsorption capacity was achieved as 225mg avidin/g biofunctional nanoparticles. Results were well fitted to the Langmuir isotherm model with the feed avidin concentration of less than 45μg/ml. Based on the experiments above, the biofunctional magnetic nanoparticles were used to separate avidin from treated egg-white solution containing large amounts of other proteins. The avidin was isolated in 92% yield with an optical purity of more than 98.5% according to the HPSEC data. The regeneration of these nanoparticles was also studied and almost 87.3% of avidin could still be recovered by these regenerated nanoparticles. [Copyright &y& Elsevier]

This study aims to enhance the color and microbiological qualities of a raw beef using natural ingredients. Nitroso-hemoglobin (NO-Hb) integrated with vitamin C (VC), calcium lactate, and ginger complexation were used as natural inhibitors against the growth of aerobic and pathogenic bacteria, namely (Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Salmonella. NO-Hb inhibited E. coli , S. aureus , and Salmonella , and enhanced the color stability more than nitrite in the minced beef model. After the multiexponential analysis of relaxation decays, the water component (T 2b) was analyzed using the low-field NMR. The results indicated that, at the 7th d of cold-storage the third component (T 2) was detected. Significant correlations were observed between T 21 and T 22 relaxation times and water-holding capacity in minced beef, implying that the LF-NMR measurements could be an efficient method for the determination and prediction of beef freshness. NO-Hb- ginger mixture, as a novel ingredient, could be used instead of nitrite in terms of meat safety. • NO-Hb, from fresh beef blood and use as a nitrate substitute • NO-Hb, VC, Ca, and ginger addition improve color and inhibit of bacteria. • NO-Hb, used as a novel ingredient used in term of safely • LF-NMR has been clearly established the changes in T2 of water. [ABSTRACT FROM AUTHOR]

This study investigated the impact of ultrasound pretreatment and phenolic binding on the structure characteristic and foaming properties of egg white (EW). EW treated without ultrasound (NEW) and with ultrasound (UEW) (power for 28% and time for 25 min: on-time 3 s and off-time 2 s) were incubated separately at 25 °C for 2 h with gallic acid (GA) and epigallocatechin gallate (EGCG) at pH 7.0. Phenolic treatment caused a significant loss of sulfhydryl content, with a more remarkable effect observed in UEW, especially at 120 μmol/g concentration. Both phenolics significantly decreased the surface hydrophobicity and slightly increased the disordered secondary structure of protein. Additionally, the microenvironment polarity of protein molecules was increased by phenolic treatment corroborated by UV absorption blue shift, especially for 240 μmol/g GA-UEW. After ultrasound pretreatment, low EGCG concentration (20 μmol/g) significantly increased the foaming ability. The 240 μmol/g EGCG treatment notably increased the reduced foaming stability by ultrasound from 81.00 to 95.10% (p < 0.05), which was due to high absolute ξ-potential value. This study has shed light on the mechanisms underlying the influence of unfolding structure by ultrasound treatment on phenolic binding. Image 1 • Phenolic treatment especially EGCG significantly decreased sulfhydryl content. • Protein surface hydrophobicity was obviously decreased by phenolic treatment. • EGCG treatment increased the foaming stability of egg white. • EGCG was stronger than GA in binding affinity with egg white. • Ultrasound pretreatment contributed to the binding of phenolic to protein. [ABSTRACT FROM AUTHOR]

This study was focused on the differences between three concentrations of four safe bio-active volatile terpenes and natural compounds (trans-cinnamaldehyde, thymol, menthol, and vanillin) on the egg yolk volatile components. In which, Headspace Solid phase Micro Extraction (HS-SPME) followed by GC/MS were used for volatiles analysis, and electronic nose (E-Nose) with 18 sensors was used for the aroma pattern. In the results, a total of 111 different volatile compounds were identified by using GC/MS. Some ketones, amines, nitro and organic acid compounds such as hexanone were significantly reduced after using these compounds. On the other hand, first principal components (PC1) of trans-cinnamaldehyde (0.1%) was decreased significantly (p <.05) to −4.8 ± 0.8, compared to the control with 4.3 ± 2.1. And, it increased benzaldehyde and nonanal peaks area significantly to 46.56 ± 14.46 and 9.22 ± 4.81 MPA. In menthol (0.1%), the content of d-limonene was decreased to 4.65 ± 0.49 MPA, compared to the control with 14.16 ± 4.95 MPA. On the other hand, by E-Nose, vanillin (0.1%) PC1 was decreased significantly to −4.48 ± 0.43. Moreover, thymol (0.1%) decreased hydrocarbon sensation to 0.448 ± 0.005. And, vanillin (0.1%) decreased hydrogen sulfide and ketones sensation to 0.169 ± 0.01 and 0.344 ± 0.01, respectively. In conclusion, this study is providing novel information to understand the effects of bio-active molecules on the biological fatty media volatility. Also, it explains how terpenes can protect egg yolk media from the unacceptable odor formation which results from the degradation of its lipids and proteins. Unlabelled Image • One hundred eleven different volatile compounds were found by HS-SPME-GC/MS. • Hexanal, nonanal, and benzaldehyde showed positive volatiles PC1 and negative PC2. • Trans-cinnamaldehyde and thymol significantly decreased yolk ketones. • Azulene was formed in trans-cinnamaldehyde and thymol (0.1%). • A significant negative correlation was found between PC1 of volatiles and E-nose. [ABSTRACT FROM AUTHOR]

Maintaining homeostasis is of utmost importance regarding human health. Several factors could protect human body's internal environment from harms and fluctuations from external environment. Regulation of physiological pH has a considerable role in maintaining human health and its metabolic functions. Several studies have shown that the interstitial body fluid pH around metabolic tissues is easily reduced due to weaker pH buffering capacity than that in the cytosol and blood circulation. Therefore, pH reduction in the interstitial fluid may cause the onset of metabolic dysfunctions. However, several dietary food components have potential benefits in maintaining the interstitial fluid pH to the normal range by improving buffering capacities, suppressing proton production, and activating proton transporters, which strengthen the effect of appropriate diet on metabolic health. Keeping deep insights about this aspect, we have summed up several facts and figures for maintaining human body homeostasis via regulation of physiological pH. Furthermore, we have discussed about different food categories and their potential renal acid load and its relation with maintaining homeostasis. Afterwards we have deeply discussed the potential beneficial role of healthy food components in different pathological conditions of human body. [ABSTRACT FROM AUTHOR]

In this study, a proteome analysis of Tibetan chicken egg yolk as well as the comparison to that of lowland chicken were performed by label-free quantitative proteomics. A total of 135 proteins were identified and abundances of 19 of these proteins were significantly different between these two groups. These differential proteins were mainly associated with oxidative stress, defense, energy metabolism and tissue development through bioinformatics analysis. To further verify the species-specific diversity of the antioxidant capacity, the antioxidative activities of egg yolk proteins were further invested in vitro and in Caco-2 cells. It was observed that both Tibetan and lowland chicken egg yolk proteins showed antioxidant activities, but the former exerted a much stronger effect. PIT54 and glutathione peroxidase 3 were considered to be antioxidant-related candidate proteins. These results provide substantial evidence for the molecular mechanisms of enhancing physical activity levels of egg yolk proteins, especially with regard to the cross-species protective mechanisms against oxidative stress. [ABSTRACT FROM AUTHOR]

This experiment was conducted to explore the differences of serum steroid hormones with age and sex in hen eggs during incubation periods for identification of males and females. The concentrations of estrone (E1), estradiol (E2), estriol (E3), testosterone (T), androstenedione (A4), and dihydrotestosterone (DHT) in serum were measured by enzyme-linked immunosorbent assays in chicken embryos on 8, 10, 12, 14, and 16 D, respectively. During the development of chicken embryo, egg weight loss was closely related to age but no sex. However, it was found that both age and sex significantly affected hormones and had obviously more effect on androgens levels. Besides E2 and T, other steroids such as E1, A4, and DHT were also significantly correlated with sex (P < 0.05). Notably, the level of T and the ratio of T to E2 were significantly higher in males than females (P < 0.05). The ratio of E1 to E2 displayed different trends in different sexes, which increased in males but decreased in females. The distribution proportions of androgens and estrogens kept stable level during the late hatching periods of 12 to 16 D. The sex differences of steroids were more obvious at the late hatching stage through PCA. These suggested that the serum hormones differences in male and female embryos played a vital role in sexual differentiation. These findings not only provided the theoretical basis for sex determination of fertilized eggs in egg-laying hen strains, but also contributed to develop a non-invasive way to sex determination of fertilized eggs to meet the modern commercial application. [ABSTRACT FROM AUTHOR]

Preserved eggs are traditional alkali‐pickled food in China and have been enjoyed by consumers and extensively studied by researchers for their nutritional tastes and their anti‐tumor, anti‐inflammatory, antioxidant, lipid‐lowering, and blood pressure‐lowering properties. To study the anti‐tumor effects of preserved eggs, this project observed the health on rats, and anti‐tumor effects and separated anti‐tumor active components on HT‐29 cells. SD rats fed for 80 days showed that preserved eggs had no significant effect on weight, food intake, blood pH, liver tissues, or organ indices. Preserved eggs significantly increased blood levels of oxidative stress markers SOD and CAT, decreased MDA levels by 0.46, 0.23, and 0.25 times. Moreover, they also increased the level of IL‐2 from 1233 to 1340 pg/mL. Two water‐soluble bioactive peptide fractions, B1 and B2, with molecular weights ≥10 kDa were further obtained from preserved eggs by ultrafiltration and Superdex Peptide 10/300 GL. The potential mechanism of B1 and B2 is to activate the internal mitochondrial apoptotic pathway and induce apoptosis by up‐regulating the expression of the pro‐apoptotic factors cytochrome C, caspase‐3, and caspase‐9 mRNA in HT‐29 cells. [ABSTRACT FROM AUTHOR]

Abstract Egg white protein was phosphorylated with microwave assistance (200 W, 300 W, 400 W, 500 W and 600 W) in the presence of sodium tripolyphosphate at pH 8.0, and the structural and foaming properties of the protein were investigated in this work. The degree of phosphorylation increased at first and then remained unchanged. Fourier Transform infrared spectroscopy showed that egg white had new characteristic absorption bands by phosphorylation. Circular dichroism spectroscopy and surface hydrophobicity analysis revealed that the phosphorylated proteins had a more unfolded and flexible structure. The phosphorylated proteins had higher absolute values of zeta potential and a lower content of free -SH. After treatment with microwave at the 500 W level, phosphorylated protein had a 0.44 times (P < 0.05) greater foaming ability and 1.1 times (P < 0.05) greater foaming stability compared with the untreated sample. The results suggested that microwave-assisted phosphorylation modification is a practical method to improve egg white protein foaming properties. Highlights • Microwave-assisted technique speeds up the phosphorylation modification reaction. • CD and H o results reveal that PP-EWP molecule becomes more unfolded and flexible. • Phosphorylation with microwave-assisted change secondary structure of EWP. • FA and FS of 500W-PP-EWP increased by 44.2% and 107.2%, respectively. [ABSTRACT FROM AUTHOR]

Phosphorylation of phosvitin has been proved to play an important role in the mineralization, but the active region of phosvitin is still not known yet. Four phosvitin phosphopeptides (PPPs) were obtained after separating from ion exchange column and desalting from gel filtration, and named as PPP0, PPP1, PPP3 and PPP4, respectively. The effect of PPP on the mineralization was investigated by pH-stat system, Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscope. SDS-PAGE and circular dichroism were applied to study the composition and the structure of PPP. Results showed that the order of promoting mineralization was as follows: PPP3 > phosvitin > PPP4 > PPP1 > control > PPP0. PPP0 and PPP1 was not involved in the mineralization, while the structure of PPP4 was too compact to promote mineralization because of its high β-sheet conformation. PPP3, which contained a 10 kDa peptide, is the most effective promoter for mineralization. LTQ-MS/MS results indicated that the phosphorylated serine clusters of phosvitin was the active region for promoting mineralization. [ABSTRACT FROM AUTHOR]

Phosvitin is a unique highly phosphorylated protein that plays a role in the regulation of mineralization. This study investigated the role of phosphorylation of phosvitin in the phase transformation of calcium phosphate in the mineralization solution. Partially dephosphorylated phosvitins (T1, T2, T3 and T4) were prepared with 2.98, 19.46, 43.39 and 71.07% of phosphate released from native phosvitin, respectively. And their effect on regulating the phase transformation was investigated, the characterization and composition analysis was performed by circular dichroism, Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. Results showed that phosvitin in the acceleration effect of phase transformation was dose-concentration effect by pH-stat titration. With lower dephosphorylation degree of phosvitin (<20%), the acceleration effect was weaker than native phosvitin, since phosphorylation and random structure of phosvitin were reduced. However, with higher dephosphorylation degree of phosvitin (>40%), the acceleration effect was enhanced compared to native phosvitin, in which the β-sheet structure was increased and phosvitin was partially hydrolyzed to phosphopeptides. The acceleration effect of phase transformation was as follows: T4 > T3 > phosvitin > T1 > T2 > Control. This study clearly demonstrated that phosphorylation of phosvitin played an important role in the regulation of mineralization. [ABSTRACT FROM AUTHOR]

One unresolved challenge in the egg industry is how to efficiently and non-invasively detect unfertilized eggs prior to incubation. This detection ability would not only significantly improve hatching rates and reduce costs but also conserve incubator space and prevent poor-quality embryos from contributing to the spread of infections. This study demonstrates a procedure for distinguishing between fertilized and unfertilized eggs prior to incubation by studying the respiratory differences between fertilized and unfertilized eggs using the Non-invasive Micro-test Technique (NMT). A customized micro-testing examination platform, NMT Egg Testing System (NMT-ETS) was constructed for the real-time monitoring of the intensity and rate of oxygen exchange between the egg and its external environment. The results from this study revealed that at room temperature, there is a significant difference in gas exchange rates between fertilized and unfertilized eggs. The results indicate that the oxygen flux of fertilized eggs exceed 20 pmol/(cm2·s), whereas unfertilized eggs show a much lower oxygen flux. Based on the results, the NMT method can be used to effectively distinguish between fertilized and unfertilized chicken eggs. [ABSTRACT FROM AUTHOR]

Chitin is the most abundant natural amino polysaccharide, showing various practical applications owing to its functional properties. However, there are barriers in the development due to the difficulty of chitin extraction and purification, regarding its high crystallinity and low solubility. In recent years, some novel technologies such as microbial fermentation, ionic liquid, electrochemical extraction have emerged for the green extraction of chitin from new sources. Furthermore, nanotechnology, dissolution systems and chemical modification were applied to develop a variety of chitin-based biomaterials. Remarkably, chitin was used in delivering active ingredients and developing functional foods for weight loss, lipid reduction, gastrointestinal health, and anti-aging. Moreover, the application of chitin-based materials was expanded into medicine, energy and the environment. This review outlined the emerging extraction methods and processing routes of different chitin sources and advances in applying chitin-based materials. We aimed to provide some direction for the multi-disciplinary production and application of chitin. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, ovalbumin (OVA) was phosphorylated by dry-heating at three different pH values (5.0, 7.0 and 9.0) and 45 °C for 12 h in the presence of sodium tripolyphosphate (STP). The results indicated that, when compared with native OVA (N-OVA), the zeta potential absolute value of phosphorylated OVA (PP-OVA) increased from 2.13 mv (N-OVA) to 13.57(PP-OVA-pH5.0), 16.00(PP-OVA-pH 7.0) and 11.20 mv (PP-OVA-pH 9.0); the volume-weighted mean diameter (D [4,3])of emulsions stabilized by the N- and PP-OVA decreased from 70.22 μm (N-OVA) to 37.16(PP-OVA-pH 5.0), 16.21(PP-OVA-pH 7.0) and 43.52 μm (PP-OVA-pH 9.0); and PP-OVA emulsions exhibited a more narrow monomodal size distribution and a smaller particle size than those of N-OVA, with the corresponding emulsifying activities index (EAI) increased from 92.71(N-OVA) to 142.51(PP-OVA-pH5.0), 224.88(PP-OVA-pH 7.0), and 150.97(PP-OVA-pH 9.0), respectively. The microscopic observation showed that the emulsion droplets of PP-OVA were more densely and uniformly distributed than those of N-OVA. Furthermore, characterization of PP-OVA by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and 31 P nuclear magnetic resonance ( 31 P NMR) revealed that phosphate groups were bound to the -OH on serine and threonine and the -NH 2 on lysine and arginine, with covalent interactions (C–O–P and C-N-P bounds) formed between OVA and STP. This study demonstrated that the introduction of phosphate groups could increase the amount of negative charge and intermolecular repulsion, decrease the particle size of droplets and improve the emulsifying ability of PP-OVA. [ABSTRACT FROM AUTHOR]

This paper studies the metabolic pathway of sucrose in pullulan fermentation by Aureobasidium pullulans . Because of its high pullulan production, sucrose proved to be the best carbon source for pullulan synthesis by A. pullulans CGMCC1234 (36.3 g/L). Compared to other carbon sources, A. pullulans cells reached the stationary phase more quickly in the presence of sucrose. The specific sugar types and concentrations occurring during pullulan fermentation were detected using High Performance Liquid Chromatography (HPLC). HPLC results revealed that sucrose did not simply break down into glucose and fructose in the medium employed. Kestose (22.69 g/L) also accumulated during early stages of fermentation (24 h), which reduced the osmotic pressure of the extracellular fluid and diminished the inhibition of cell growth and pullulan production. β-Fructofuranosidase activity strongly depended on the carbon source. Sucrose was the best inducer of β-fructofuranosidase production. However, β-fructofuranosidase production did not directly and/or proportionally correlate with the growth of A. pullulans cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel chitinase EaChi40 was isolated from Exiguobacterium sp., and its gene was expressed in E. coli BL21 (DE3). • Recombinant chitinase EaChi40 showed good cold-adapted catalysis and thermal stability. • Crayfish shell was treated with ball milling and ultrasonic-assisted decolorization to promote enzymatic hydrolysis. • EaChi40 effectively bio-transformed crayfish shell chitin by producing chitin oligosaccharides. Crayfish have become a heavily consumed food and its chitin-rich shell is of great value in terms of waste conversion. This study found a novel chitinase (EaChi40) from a marine bacterium Exiguobacterium antarcticum. The gene was cloned and expressed as a soluble protein of 40 kDa, having optimal activity at pH 6.0 and 30 °C. EaChi40 showed good stability and high specific activity, and kinetic studies found K m and V max were 0.86 mg/mL and 13.66 μmol/min/mg. For conversion crayfish shell into oligosaccharides, ball milling and ultrasound-assisted hydrogen peroxide decolorization were applied to pretreat crayfish shell to facilitate its hydrolysis. After the enzymatic conversion, the hydrolysis products of chitobiose and N-acetyl-D-glucosamine were 9.09 mg/mL and 9.21 mg/mL, respectively. EaChi40 efficiently degraded crayfish with a high hydrolysis rate of 76.1%. It is expected to be a good candidate for the production of chitin oligosaccharides in the food and biological fields. [ABSTRACT FROM AUTHOR]

Phosvitin (PV) is the main phosphoprotein in egg yolk, with the highest degree of phosphorylation known in nature. The PV and resveratrol (Res) can form a complex, thus effectively improve the solubility of Res. In this work, the interaction between Res and PV was investigated by the fluorescence spectroscopy and molecular docking. The fluorescence emission intensity of PV became weak along with a red shift when it interacted with Res and the antioxidant activity was enhanced. The quenching constants of the interaction systems were 1.12×104 M–1 and 9.40×103 M–1 at 25°C and 35°C, respectively, which indicated the presence of static quenching phenomena between them. The binding constant was 1.80×104 M–1, and the number of corresponding binding sites was approximately equal to one. The thermodynamic results revealed the combination was spontaneous, and the change of enthalpy and entropy was ∆H = 53.50 kJ/mol, ∆S = 261.00 J/mol·K, respectively. It indicated that the interaction forces between Res and PV were mainly hydrophobic interaction and hydrogen bonding. Molecular docking showed the binding mode, which was consistent with the experiment results. The research on the interaction between Res and PV provided theoretical guidance for the application of Res in food. Practical Application: PV is the most highly phosphorylated protein in nature and has pro‐calcium absorption effects. Res is a polyphenol with strong antioxidant and anti‐inflammatory activity, but its poor solubility limits its application. In this study, the solubility of Res was considerably enhanced by compounding Res and PV, and the antioxidant activity of Res was well retained. It increases the value of Res in food and other applications and opens up new possibilities for processing and utilization of PV. [ABSTRACT FROM AUTHOR]

BACKGROUND: Respiration is an important physiological activity of eggs and is closely related to their freshness. To further observe the diffusion of carbon dioxide released by egg respiration, we used a respirometer to measure the respiration parameters of eggs stored at room temperature and performed a respiration simulation using Fluent software. This paper also explores the relationship between respiratory intensity, freshness, and storage period. RESULTS: The results demonstrate that the diffusion of carbon dioxide released from the respiration of eggs is related to the characteristics of heavy gas diffusion. By comparison, the simulated value (0.0199 m s−1) is close to the experimental value (0.0208 m s−1), which indicates that the simulation and analysis results are valid. In addition, the logarithmic model was used to assess the relationship between respiration intensity, Haugh unit, and the yolk index (R2 values 0.89 and 0.87). The R2 of the relationship between the real and the predicted Haugh unit value and the yolk index are 0.9 and 0.84 respectively, indicating that the model is a good fit. The equivalent egg age model was established using nonlinear regression, where the correlation coefficient R was 0.888 and P < 0.01, indicating it was both stable and reliable. CONCLUSION: The standard k–ε model is suitable for egg respiration simulation analysis. Respiratory intensity can be used as a potential index for nondestructive testing of egg freshness, which is a new method for nondestructive testing of egg freshness and storage period. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND Hen egg white ovomacroglobulin ( OVM) possesses a variety of bioactivities and could potentially be used as a pharmaceutical agent. It has been reported that OVM is involved in wound healing and cancer pathological processes, and previous results suggest that OVM plays a potential role in cell proliferation and migration; however, this has not yet been proven. In the present study, the effects of OVM on fibroblast proliferation and migration were evaluated. RESULTS Results of cell counting, cell viability, and cell cycle indicated that proliferation of fibroblasts was not altered by OVM treatment. However, scratch assays showed that OVM could promote the migration of 3 T6 mouse embryonic fibroblasts and human skin fibroblasts ( HSF). Also, the adhesion of HSF to the collagen matrix was also enhanced by OVM treatment. RT-qPCR and western blot analysis showed that β1-integrin, β-tubulin, and β-actin were up-regulated while E-cadherin was down-regulated in OVM-treated HSF cells. The effect of OVM was silenced after forming a complex with trypsin, suggesting that the protease inhibitory ability of OVM is important for its effect on cell migration. CONCLUSION These results suggested that promotion of OVM on cell migration was achieved by enhancing cell adhesion to extracellular matrix, reducing intercellular aggregation, and strengthening cytoskeleton. The finding of the promotion effect of OVM on cell migration is important for understanding its role in wound healing and cancer pathological processes. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Lipid oxidation, fatty acid profile and microstructure of duck egg supplemented with garlic oil were monitored over the salting period. The antioxidant activity of garlic oil was measured by 1,1-diphenyl-1-picrylhydrazyl (DPPH) assay and its activity was compared to that of standard synthetic antioxidants (butylated hydroxyl toluene and gallic acid). The scavenging percentage of garlic oil increased in a dose-dependent manner. The supplementation of garlic oil altered the characteristics of duck egg during salting. In addition, oil exudation by yolk and lipid oxidation (thiobarbituric acid reactive substances) showed an increasing trend concomitant with salting time. Microstructure observation revealed comparatively loose shell membrane structure in duck egg supplemented with garlic oil, which facilitates the transportation of oil toward the yolk. These findings contribute to a better understanding that garlic oil can be used as a potential antioxidant agent and a healthy natural food additive. [ABSTRACT FROM AUTHOR]

Summary: Heat treatment will affect the nutritional properties and potential bioactivity of food materials. The aim of this work was to evaluate the effect of different thermal treatment (4, 56, 65 and 100 ℃) and invitro gastrointestinal digestion on the antioxidant activity of egg white hydrolysate. The results demonstrated that egg white hydrolysate treated at 65 ℃ exhibited the highest antioxidant. Remarkably, the simulated digestion significantly increased antioxidant activity of egg white hydrolysate. Furthermore, we identified twenty‐four potential antioxidant peptides by performing mass spectrometry and bioinformatic analysis. Six peptides were selected based on the activity prediction score of the online tool. The results showed that P6 (ACPECPK) possessed the most outstanding antioxidant properties and had low cytotoxicity and allergenicity. Bioinformatics technology combined with biochemical assays may offer a way for discovering novel antioxidant peptides from different kinds of food under various heat treatment conditions. [ABSTRACT FROM AUTHOR]

Sialic acids (SA) are widely found as components of oligosaccharide units in mucins, glycoproteins and other microbial polymers in nature food. The aim of this study is to create a new fluorimetric detection method applied for determinating SA in egg products by using a sensitive lectin-CdTe quantum dots (QDs) nanoprobe. Water-soluble and high luminescent CdTe QDs were conjugated with sambucus nigra bark lectin (SNA) as probe for SA detection. As a result of specific interaction between SA and SNA-CdTe QDs, the conjugations finally lead to the change of a fluorescent signal. Under optimal conditions, fluorescence intensity increase linearly with the increase of the concentration of SA ranging from 12 to 680 ng/mL. The low detection limit is 0.67 ng/mL. This quick and selective analysis method for SA detection has been used in synthetic samples and egg products with recovery between 97.92% and 110.42%, which demonstrates the application of this assay is feasible and practical. [ABSTRACT FROM AUTHOR]

Metal–protein interaction for regulating the function and structure of proteins is of major interest. We demonstrate here that the addition of 9 μmol Mg 2+ per mg ovomucin resulted in a 2.0-fold increase in the adhesion capacity of ovomucin to New Disease Virus (NDV) using ELISA method. The hemagglutinin inhibition rate of 100 μg/mL ovomucin–Mg 2+ mixture (9 μmol Mg 2+ per mg ovomucin) to NDV increased to 55.61%, which is significantly higher than that of the pure ovomucin ( P < 0.01). Binding characteristics of ovomucin to Mg 2+ were then evident by fluorescence and FT-IR spectroscopy as well as dynamic light scattering (DLS) technology. Fluorescence and FT-IR spectroscopy results suggest that Mg 2+ prefers to interact with the carbohydrate moiety of ovomucin without significant changes in the secondary structure when Mg 2+ concentration is less than 9 μmol/mg ovomucin. When Mg 2+ increases to 16 μmol/mg ovomucin, it gives rise to changes in secondary structure, and forms a more compact configuration. This is supported by the hydrodynamic radius of ovomucin with and without Mg 2+ binding as examined by DLS. The Mg 2+ bound in regulating the structure and activity of ovomucin provided important insight into the effect of metal ions on ovomucin binding to pathogens. [ABSTRACT FROM AUTHOR]

Breathing is an important physiological activity of egg as a living organism, and it has a great influence on its storage, conveyance and incubation. Therefore, it is of great significance to study egg's breathing regularity and respiration intensity in a day and during its storage time in a month. In this paper, non-invasive micro-test technique (NMT) was used to real-time monitor O2 flux passing in and out the eggs through the eggshell and study the breathing regularity and the respiration intensity of the eggs. With this method, gas exchange (O2) was measured and it was confirmed that breathing indeed exists. In order to study egg's respiration in a day, a customized micro-testing examination platform was constructed for the real-time monitoring of the intensity and rate of oxygen exchange between an egg and its external environment at 4 time points (6:00, 12:00, 18:00, and 24:00). On the other hand, egg's O2 flux was measured at the same time in a day during a month as to seeking for breathing regularity in its storage time. It was indicated that the optimal distance of probe towards the egg surface was 50 μm and the blunt end of the egg was selected as the optimum measurement location via the pre-experiment. The results show that there are three breathing patterns of eggs, consuming O2, exhaust O2, and both including consuming and exhausting O2. After group A testing, it is concluded that both fertilized and non-fertilized eggs breathe strong at dawn and weak at noon regularly in a day and the respiration intensity of the two types of eggs perform difference at different time points. Fertilized eggs have more active physical activity and the process of metabolism than those of non-fertilized ones. Fertilized egg respiration shows significant difference (P<0.05) at noon and dawn in a day, but non-fertilized egg does not. In addition, after group B testing, it is intended that during storage time in a month, there exists two breathing peaks in its storage period in a month, and each peak appears at the eggs quality changing time. The second peak value exceeds the first peak value. It reveals that there's a unique breathing pattern of eggs that O2 respiration rate is high when life metabolism is active, and low when life metabolism is negative. Eggs laid lately are breathing relatively positive. This study can provide a reference for optimizing storage conditions, improving the hatchability of fertilized eggs and hatching egg embryo in further research. [ABSTRACT FROM AUTHOR]

The aim of this paper was to demonstrate a rapid and selective fluorescence-linked immunoassay method based on quantum dots as the fluorescent marker for the detection of Salmonella Enteritidis on eggshell. Highly-fluorescent and water-soluble CdTe quantum dots were prepared by using thioglycolic acid and 1-thioglycerol as ligands and were then conjugated with anti-Salmonella antibodies. As a result of specific interaction, Salmonella Enteritidis were specifically captured by bioconjugated CdTe quantum dots which led to the detection of a fluorescent signal. The bacterial cell images were obtained using fluorescence microscopy. Under optimal conditions, the quenched fluorescence intensity increased linearly with the log total count of Salmonella Enteritidis ranging from 3 × 102 to 3 × 107 CFU/mL within 1–2 h. The low detection limit was 1 × 102 CFU/mL without sample enrichment. This method was satisfactorily applied to the analysis of egg samples, which was demonstrated as a simple scheme for quick and selective detection of Salmonella Enteritidis on eggshell. [ABSTRACT FROM AUTHOR]

[Display omitted] • SEW improved the texture properties of steamed bread. • SEW is utilised as a sustainable ingredient in steamed bread formulations. • Micromorphology showed a compact and smooth structure after adding SEW. • Enrichment of steamed bread with 15% SEW shows significant acceptability. Steamed bread has long been an important part of Chinese cuisine. This study investigated the effects of salted egg white (SEW) (5, 10, 15, and 20% w/w) on the quality of steamed breads. Findings revealed that SEW notably enhanced the bread's volume and texture, with a 20% inclusion significantly boosting water retention and rheological properties, albeit reducing bread's lightness. In addition, the H-bond absorption band intensity in the Fourier transform infrared spectroscopy (FTIR) analysis showed increased peak intensities with higher SEW levels, indicative of protein structure alterations. X-ray diffraction confirmed the presence of an amylose–lipid complex. Scanning electron microscope (SEM) and Confocal laser scanning microscope (CLSM) imaging depicted a smooth, consistent protein network with SEW addition. Consumer sensory evaluation responded favourably to the SEW15 steamed bread, suggesting its potential for food industry application. Overall, the study considers SEW an effective ingredient for improving steamed bread quality. [ABSTRACT FROM AUTHOR]

This study prepared emulsion gels by modifying ovalbumin (OVA)-flaxseed oil (FSO) emulsions with transglutaminase (TGase) and investigated their properties, structure and oxidative stability under different enzyme reaction times. Here, we found prolonged reaction times led to the transformation of α-helix and β-turn into β-sheet and random coil. The elasticity, hardness and water retention of the emulsion gels increased significantly, but the water-holding capacity decreased when the reaction time exceeded 4 h. Confocal laser scanning microscope (CLSM) indicated extended enzyme reaction time fostered oil droplet aggregation with proteins. Emulsion gel reduced FSO oxidation, especially after 4 h of the enzyme reaction, the peroxide value (PV) of the emulsion gel was reduced by 29.16% compared to the control. In summary, the enzyme reaction time of 4 h resulted in the formation of a dense gel structure and enhanced oxidative stability. This study provides the potential applications in functional foods and biomedical fields. [Display omitted] • A novel FSO - encapsulated emulsion gel was constructed by inducing OVA with TGase. • Extended enzymatic reaction time improved emulsion gel properties and structure. • TGase - treated OVA aggregated more on the surface of the oil droplets. • Emulsion gel enhanced the oxidative stability of FSO during storage. [ABSTRACT FROM AUTHOR]

The foaming property of egg white (EW) is essential in food processing. In this study, we investigated the effect of ultrasound combined with adding different concentrations (0, 0.4, 0.5, 0.6, 0.7, and 0.8 %, m/v) of flaxseed gum (FG) on EW foaming. The results showed that the cooperation of ultrasound treatment and FG significantly improved the foaming stability. Regarding details, FG reduced the sulfhydryl content and surface hydrophobicity of EW proteins while increasing the average particle size and PDI value. Despite the ultrasound treatment, FG significantly improved the foaming stability from 62.83% to 99.82% (p < 0.05). Based on the analysis of ξ-potential, surface tension, rheology, etc., FG improved the EW microenvironment, which is conducive to foaming stability. As a new type of polysaccharide, FG combined with ultrasound can significantly improve the foaming properties. This research could solve the problem of reduced foaming stability of EW treated by ultrasound alone, making promising applications in the food industry. [Display omitted] • Ultrasound combined with flaxseed gum improved the foaming of egg white. • Flaxseed gum overcame the problem that ultrasound reducing the foaming stability. • Flaxseed gum formed a viscoelastic interfacial film to increase surface tension. • Egg white protein's structure was more compact and increased foaming stability. [ABSTRACT FROM AUTHOR]

Respiration plays a crucial role in the physiological development of embryos throughout the entire incubation process and serves as a vital indicator for discerning unfertilized eggs and embryos that have stopped development. This article explores the relationship between egg respiration, fertilization status, and chicken embryo viability. First, it studied the changes in respiration of fertilized and unfertilized eggs during the early stages of incubation (Day 1–3) and found that the CO 2 production of fertilized eggs gradually increased, while those of unfertilized eggs gradually decreased. Moreover, significant differences in respiration between fertilized and unfertilized eggs were observed on the second day of incubation. Next, we employed Random Forest (RF), Logistic Regression (LR), and Support Vector Machine (SVM) models to differentiate between fertilized and unfertilized eggs. Notably, the SVM algorithm exhibited exceptional performance in discriminating between fertilized and unfertilized eggs, achieving a remarkable test set accuracy of 98.41 %. Finally, a Bayesian algorithm was applied to classify embryos as either dead, weak, or viable in middle and later stages of incubation. Bayesian discriminant analysis yielded compelling results, achieving a 100 % detection rate for deceased embryo eggs. The outcomes of this study provide a robust theoretical foundation and empirical data to advance non-destructive testing methodologies for poultry eggs. Graphic abstract. [Display omitted] • Identification of weak and dead embryo based on respiration. • Respiration analysis of fertilized and unfertilized eggs. [ABSTRACT FROM AUTHOR]

Abstract: The avidin–biotin interaction was evaluated systematically by fluorescence spectroscopy under different conditions of temperature, pressure, pH, metal ions, incubation time and initial avidin concentration. The binding constant was calculated according to the modified Stern–Volmer equation, which deduced the existence of static quenching mechanism. The data obtained revealed that avidin–biotin interaction exhibited temperature, pH, metal ions, incubation time and initial avidin concentration sensitivity. The binding constants decreased with increase in temperature, while the binding sites were independent of temperature. The values of thermodynamic parameter ΔH (−149.85kJmol−1) and ΔS (−284.26Jmol−1 K−1) suggested hydrogen bonds and van der Waals played a major role in the reaction. The binding constants between avidin and biotin increased firstly and then decreased gradually with the increase of pH values. Metal ions can also affected the binding constants between avidin and biotin. The association kinetics firstly acquired by the combination of the change in fluorescence per unit time and the modified Stern–Volmer equation indicated that the reaction time required to reach equilibrium was 2200s, and the average reaction rate for the binding process was very high in the first 180s. Reaction of the avidin in the first 180s was more than 40% of the total avidin involved in the whole process. [Copyright &y& Elsevier]

Abstract: Purification of ovomucin is still an empirical technique and sometimes insufficient quantities of ovomucin are purified to allow characterization. Here we aimed to investigate the effect of MgCl2 on the purity and bioactivity of ovomucin during isoelectric precipitation process and to develop an effective protocol to prepare pure ovomucin with high bioactivity. It was found that addition of MgCl2 is an alternative approach to remove lysozyme from ovomucin, and that the hemagglutination inhibition (HI) activity of ovomucin with MgCl2 against New Disease Virus (NDV) was about two times higher than the protein without salts. Thus, an improved procedure comprises a precipitation with 0.05mol/L CaCl2 followed by precipitation with 0.05mol/L MgCl2 was developed for the isolation of ovomucin. Better adhesion property of ovomucin was observed when low concentration of MgCl2 was added in the designed ELASA test, whereas the adhesion property of the pure ovomucin without salts to NDV was lower. Thus, magnesium (II) plays an important role in the activity of ovomucin, and the alternative method developed in this study may significantly facilitate the further research on the mechanism of ovomucin activity. [Copyright &y& Elsevier]

Abstract: A new method for determination of lysozyme with high sensitivity based on Resonance Rayleigh scattering (RRS) by using Au nanoparticles as a probe was proposed in this experiment. The RRS spectrum, nonlinear scattering (second-order scattering (SOS), frequency doubling scattering (FDS)) spectra and absorption spectrum of the Au nanoparticles–lysozyme system have been analyzed. In addition, the effects of several factors on scattering intensities were investigated, including pH value of solution, amount of Au nanoparticles, mixing sequence of each reagent and the coexisting substances. The results showed that the coexisting substances have little influence on the RRS intensities of the systems. Moreover, the possible mechanism for the RRS enhancement of Au nanoparticles–lysozyme system was preliminary discussed. The RRS method for determination of lysozyme has good sensitivity and selectivity with the detection limits 30.1ng/ml. The contents of lysozyme were determined with recoveries of 98.2–105.4% and relativity relative standard deviation (RSD) of 0.3–3.7%, respectively. It proved that the method established in our study is suitable for the determination of lysozyme in synthetic sample and natural chicken egg white sample. [Copyright &y& Elsevier]

• HPCD process affect liquid whole egg quality as well as disposal of sterilization. • HPCD process promoted interfacial properties of liquid whole egg. • The physicochemical properties of protein were changed by HPCD. • The apparent viscosity of LWE declined after HPCD treatment. In this research, the impact of High Pressure Carbon Dioxide (HPCD) on the physicochemical, interfacial and rheological properties of liquid whole egg (LWE) was investigated. HPCD treatment increased the solubility, free sulfhydryl groups and surface hydrophobicity of LWE. The highest foaming ability (186%) and foaming stability (72%) were obtained at 60 min of HPCD treatment, which were 1.3-fold and 1.4-fold those of the control group (147% and 51%, respectively). Compared with the control group, the LWE emulsion had a minimum particle size (16.3 μm) when the treatment time was 75 min, and the highest absolute value of zeta potential reached 7.66 mV when the processing time was 60 min. HPCD treatment decreased the apparent viscosity of LWE at a low shear rate. Dynamic viscoelastic characteristics indicated that both the G' and G" moduli of LWE under the HPCD process were lower than those of the control group at any frequency. [ABSTRACT FROM AUTHOR]

Hydrogels could be used as wound dressings, but most protein-based hydrogels lack anti-bacterial effects. Here, we successfully prepared a silver ion cross-linked thiolated protein hydrogel (thiolated Ovalbumin and Gelatin, O3G7). The wound photographs showed that the healing rate (96.23 %) of hydrogel-treated mice was higher than the control group. Meanwhile, the hydrogel increased the granulation tissue's total protein content. Furthermore, it significantly increased the collagen content, consistent with the results of Masson's trichrome (MT) staining and immunohistochemical analysis of type I collagen (Col I). The results of hematoxylin and eosin (H&E) staining showed the growth and proliferation of inflammatory cells, granulation tissue, fibroblasts, blood vessels and hair follicles in acute wounds. O3G7 hydrogel had fewer inflammatory cells and more neovascularization, and hair follicle tissue and intact epidermis could be observed. The results of immunofluorescence and immunohistochemistry showed that the O3G7 group reduced the expression of tumor necrosis factor (TNF)-α (56.87 % of the control group) and upregulated the expression of transforming growth factor (TGF)-β (1.29 times of the control group). These results suggest that O3G7 hydrogel significantly affects the healing of acute wounds. This study demonstrates that hydrogels prepared from food-derived proteins will be promising and bio-safe candidates in bioengineering. [Display omitted] • Silver icon brought the general protein-based hydrogel with antibacterial activity. • The thiolated protein hydrogel has both a dense structure and excellent biocompatibility. • The tOVA/tGel@Ag hydrogels accelerate the healing of acute wounds in mice observably. [ABSTRACT FROM AUTHOR]

• The chitosan and eggshell membrane powder composite macroparticles were prepared. • The eggshell membrane powder increased the porosity of chitosan macroparticle. • The eggshell membrane powder improved the activity sites for enzyme immobilization. • The increase in pore size could improve the activity of immobilized protease. Chitosan-based macroparticle is a common carrier for enzyme immobilization applied in food industry. Driven by the requirement of large carrier pores for the biomacromolecular substrates such as protein, the eggshell membrane powder (ESMP) was employed as multifunctional porogen to improve the physicochemical structure of chitosan-based macroparticles. The prepared macroparticles were characterized by SEM, XRD, FTIR, Raman spectroscopy, nitrogen adsorption-desorption isotherms, and thermogravimetric analysis. The results showed that an increase of ESMP percentage could improve the porosity of macro holes in macroparticles, and it also enlarged the size of mesopores. Moreover, the ESMP significantly increased (P < 0.05) the amount of papain immobilization, whereas the specific activity of immobilized papain achieved a maximum value of 871.95 U/mg at CSESM2 and then declined with the increase of ESMP. Therefore, the inclusion of 20 % ESMP in chitosan-based macroparticles gave the highest activity of its immobilized protease. [ABSTRACT FROM AUTHOR]

Camel meat is presented as a primary source of nutritional supplement for fulfil human's nutritional needs in Arabian, African, and in some Asian countries, particularly in areas where weather is hot. In this study, the proximate compositions and microbial property of camel meat was compared with beef, mutton and chicken by analyzing the contents of moisture, total fat, crude protein, minerals, vitamins, amino acids and fatty acids. The results revealed that camel meat has higher (P < 0.05) moisture, minerals, vitamins and amino acids content but lower total fat, cholesterol, and ash content than other meats. The results also found that camel meat has lowest total microbial count (TBC) and it was free from pathogenic bacteria as compared to other meats. Moreover, camel meat was better in all the examined samples and healthier for human consumption. These results suggested that camel is a low-fat, nutritious and safe meat. • Camel meat has high moisture, minerals, vitamins, and amino acids than other meats. • Camel meat has less cholesterol, lowe TBC , and free from pathogenic bacteria. • Camel meat is better in all the examined samples and healthier for a human. • Meat quality maintained at a constant low temperature to avoid freeze-thaw cycles. • The nutritional value of camel meat is much better than other animal's meats. [ABSTRACT FROM AUTHOR]

Preserved egg, a traditional Chinese egg product, is regarded as an anti-inflammatory food in traditional Chinese medicine. This study was aimed to examine anti-inflammatory effect of the simulated gastrointestinal digestive products of whole preserved egg (DWPE), preserved egg white (DPEW), and preserved egg yolk (DPEY) on lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The results demonstrated that DWPE, DPEW, or DPEY inhibited the LPS-induced secretion of Nitric oxide (NO), without marked cytotoxicity. The DWPE, DPEW, and DPEY significantly suppressed the secretion of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-6. Particularly, the inhibition rate of DPEW on NO, IL-6, and TNF-α could reach 25 to 27%, 31 to 42%, and 26 to 38%, respectively (P < 0.05). Furthermore, the DPEW and DPEY downregulated the gene expression of Cyclooxygenase-2 and inducible nitric oxide synthase in a dose-dependent manner. Taken together, this study indicated that DWPE, DPEW, and DPEY, especially DPEW, might serve as functional food for anti-inflammatory therapy. [ABSTRACT FROM AUTHOR]

• Nano-TiO 2 has enhanced properties of the pullulan film. • The WVP value of film was obtained minimally at 6.6 × 10−4 g m/m2 h KPa. • The TS value of film was obtained maximally at 15.99 MPa. • The ability of the blend film to block UV has been significantly improved. In this study, effects of nano-TiO 2 on the microstructural, physical, mechanical and optical properties of pullulan films were investigated. The results showed that the addition of nano-TiO 2 improved the water vapor barrier properties of the film due to the tortuous path formed by nano-TiO 2. When the concentration of nano-TiO 2 was 0.04 g/100 mL, the tensile strength of the film showed a maximum value (15.99 MPa). The elongation at break of the film continued to decrease with the increase of nano-TiO 2. The TEM analysis showed that higher concentration of nano-TiO 2 would cause greater aggregation. Meanwhile, the results of FTIR and low-field NMR indicated that the miscibility between pullulan and nano-TiO 2 was due to the formation of intermolecular hydrogen bonds during film formation. Furthermore, the addition of nano-TiO 2 significantly improved the film barrier properties to ultraviolet light. [ABSTRACT FROM AUTHOR]

High-density lipoproteins from egg yolk (EYHDL), also called lipovitellenin, is the second largest constituent of egg yolk (EY), and possesses important functional properties in lipid metabolism for its high content of phospholipids. To better understand its lipid profile, a lipidomic analysis based on ultrahigh-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) and gas chromatography and mass spectrometry (GC–MS) was conducted. Compared with EY, the lower level of triglyceride (TG), higher level of phosphatidylcholine (PC), phosphatidylinositol (PI), and diglyceride (DG) were found in EYHDL (p < 0.01). The orthogonal partial least squares-discriminant analysis (OPLS-DA) revealed that the lipid profile of EYHDL was clearly discriminated from EY. Volcano plots combined with S-plots showed that the differential lipids in EYHDL were 22 significantly downregulated TG with long-chain fatty acids in ES+ , and 30 markedly upregulated lipids including PC, phosphatidylethanolamine (PE), and PI with long-chain fatty acids in ES− (p < 0.01). GC–MS analysis showed higher level of C18:1 and C22:6, and lower level of C16:0 in EYHDL than EY. In summary, EYHDL could serve as a favorable lipid source for human diets for its higher PC, PI, and lower TG. [ABSTRACT FROM AUTHOR]

• Genipin and glutaraldehyde could transform into polymer and dimer, respectively. • Hydrogen bonds could improve the density of the network structure of FILM-GEs. • Polymerization of genipin greatly affected the swelling ratio of FILM-GEs. • Chitosan based film crosslinked by genipin had better mechanical properties. In this study, genipin and glutaraldehyde in varied concentrations were utilized in chitosan crosslinking under alkaline condition. A UV/Vis analysis was used to investigate the molecular structure of genipin and glutaraldehyde in an aqueous alkaline solution. The results showed the formation of glutaraldehyde dimer and polymerized genipin. The FTIR-ATR, SEM, DSC, XRD, mechanical properties, crosslinking degree and swelling ratio of chitosan based films crosslinked by genipin and glutaraldehyde were determined. The results indicated that the hydrogen bonds formed between genipin and chitosan enabled the films crosslinked by genipin (1 and 5 mmol/L) to have a higher degree of crosslinking, but a lower swelling ratio than glutaraldehyde (1 and 5 mmol/L). Genipin enabled the chitosan-based film to possess better mechanical properties and crystallinity than glutaraldehyde. The polymerization of genipin had a substantial effect on the network structure and swelling behavior of chitosan-based films crosslinked by genipin. [ABSTRACT FROM AUTHOR]

Highlights • Alcalase and neutrase were used for preparing calcium-binding peptide from pig bone. • The chelating conditions was optimized by response surface methodology. • The differences of characterization between peptide and peptide-calcium chelate were given. • The stability of chelate against to pH, temperature and gastrointestinal digestion was evaluated. • Peptide-calcium chelate could significantly improve calcium transport in Caco-2 cell monolayer. Abstract In this study, alcalase and neutrase were used in combination to prepare collagen peptides with high calcium binding ability. The optimal conditions for the preparation of peptide-calcium chelate (mass ratio of peptide/calcium of 4.5:1 for 40 min at 50 °C and pH 9) were determined by response surface methodology (RSM), under which a calcium chelating rate of 78.38% was obtained. The results of Ultraviolet–Visible (UV–Vis), fluorescence and Fourier transform infrared (FT-IR) spectra synthetically indicated that calcium could be chelated by carboxyl oxygen and amino nitrogen atoms of collagen peptides, thus forming peptide-calcium chelate. The chelate was stable at various temperatures and pH values, and exhibited excellent stability in the gastrointestinal environment, which could promote calcium absorption in human gastrointestinal tract. Moreover, Caco-2 cell monolayer model was used to investigate the effect of peptide-calcium chelate on promoting calcium absorption. Results showed that peptide-calcium chelate could significantly improve calcium transport in Caco-2 cell monolayer and reverse the inhibition of calcium absorption by phosphate and phytate. The findings provide a scientific basis for developing new calcium supplements and the high-value utilization of pig bone. [ABSTRACT FROM AUTHOR]

Abstract In this study, ovalbumin (OVA) was phosphorylated under wet-heating in the presence of sodium tripolyphosphate at pH 6.0 and 60 °C for 1, 2, 3, 4 and 5 h, and the structural and physical properties of phosphorylated OVA (P-OVA) were investigated. The FT-IR spectrum confirmed the covalent attachment of the phosphate group to OVA. New possible phosphate sites (Ser-221, Ser-269, Tyr-281 and Ser-324) were detected by using liquid chromatography in tandem with mass spectrometry. Circular dichroism (CD) spectra demonstrated that P-OVA molecular became more flexible and disordered. The decreased fluorescence intensity indicated that the chromophore microenvironment became more exposed and polar because of conformational changes. The surface hydrophobicity (H 0) and the absolute value of zeta potential of P-OVA obtained at 5 h was 1.8 and 1.5 times higher than that of N-OVA. Foaming ability (FA) and foaming stability (FS) were enhanced by 1.7 and 4.4 times after wet-heating phosphorylation for 4 h, which were up to 87.0% and 28.5%, respectively. Furthermore, the correlation analysis suggested that FA was significantly correlated to random structure (P < 0.01) and H 0 (P < 0.01), and zeta potential was related with FS (P < 0.05). Graphical abstract Image 102 Highlights • Ovalbumin was phosphorylated by sodium tripolyphosphate under wet-heating. • Possible phosphate sites were detected by LC-MS/MS. • Structural changes were confirmed by fluorescence and CD spectrum. • H 0 and the absolute value of zeta potential increased after the phosphorylation. • Foaming ability and stability were promoted by phosphorylation. [ABSTRACT FROM AUTHOR]