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To explore anti-aging and antioxidant activities of Phyllophorus proteus hydrolysate fraction (PPHF) on Caenorhabditis elegans, the physiological and biochemical indicators of C. elegans fed 0.5, 2.0 mg/mL and 8.0 mg/mL PPHF were determined. The results showed that PPHF was beige in color, and its L* and b* values were 81.28 and 15.88, respectively. The proportion of oligopeptides with molecular mass of 180–1 000 Da in PPHF was 63.76%, and the proportions of glutamic acid and glycine were 19.50% and 15.34%, respectively. After being fed 0.5, 2.0, and 8.0 mg/mL PPHF, the lifespan of C. elegans was increased by 22.43%, 54.60%, and 78.89%, respectively, under normal conditions, and also increased under thermal or oxidative stress. The body length of C. elegans was increased significantly by feeding 0.5 mg/mL PPHF, while the swallowing frequency was significantly increased by feeding 2.0 mg/mL PPHF. The body bending frequency of C. elegans fed 0.5 and 8.0 mg/mL PPHF was increased by 7.75% and 43.71%, respectively, when compared with the control group on the second day of incubation. PPHF significantly reduced the content of reactive oxygen species (ROS) in C. elegans, and increased the antioxidant enzyme activity, glutathione content and total antioxidant capacity in a dose-dependent manner. These results indicated that PPHF could improve the physiological function and prolong the lifespan by enhancing antioxidant capacity in C. elegans.

In this study, the effects of different recovery methods on the structure and functional properties of sarcoplasmic proteins from silver carp surimi wash water were analyzed. The results showed that acidic pH-shifting and heat treatment had a great effect on the degree of conversion of –SH groups to disulfide bonds, surface hydrophobicity, intrinsic tryptophan fluorescence intensity, solubility and foamability of sarcoplasmic proteins. Secondary structure analysis showed that freeze drying and heat treatment gave rise to a higher relative content of β-sheet; isoelectric point precipitation, acidic pH-shifting alone and in combination with chitosan flocculation resulted in a higher relative content of random coil; chitosan flocculation led to a higher relative content of β-turn. These methods consistently yielded a lower relative content of α-helix, and caused the secondary structure of sarcoplasmic proteins to transform from an ordered to a disordered state. In addition, chitosan could bind to sarcoplasmic proteins to form large molecular mass complexes, whereas acidic pH-shifting caused partial decomposition of sarcoplasmic proteins. The structural changes cause by the different recovery methods affected the functional properties of sarcoplasmic proteins. The sarcoplasmic proteins prepared by acidic pH-shifting coupled with chitosan flocculation had much higher surface hydrophobicity and consequently poorer emulsifying properties, while those obtained by freeze drying, isoelectric point precipitation, and chitosan flocculation had stronger emulsifying properties. Notably, chitosan treatment significantly improved the emulsifying properties of sarcoplasmic proteins.

In order to explore the interaction between lipid and protein in film-forming solutions and films, the effects of linoleic acid concentration (0%, 10%, 20%, 30% and 40% relative to protein mass) on the viscosity of 11S globulin film-forming solutions, and the microstructure and physicochemical properties of the resulting films were studied. Confocal laser scanning microscopic (CLSM) images showed that the size of oil droplets in the film-forming solution increased with increasing linoleic acid concentration, and it further increased after drying. According to the results of scanning electron microscopy (SEM), oil droplets accumulated on the upper surface of the smooth and dense protein films after adding linoleic acid, while the lower surface became rough without accumulation of oil droplets on it. After adding 40% linoleic acid, the glass transition temperature, tensile strength and water vapor permeability of the film decreased from 53.50 ℃, 12.67 MPa and 2.52 × 10−10 g/(m·Pa·s) to 50.38 ℃, 7.30 MPa and 1.83 × 10−10 g/(m·Pa·s), respectively, while the elongation at break increased from 95.58% to 198.15%. Molecular dynamics simulation showed that 11S globulin did not interact with linoleic acid below 200 ns. The proportion of ionic bonds and disulfide bonds in the 11S globulin film decreased with the addition of linoleic acid, while the proportion of hydrophobic interactions and non-disulfide covalent bonds increased. These results suggest that the addition of linoleic acid can change the chemical interactions among proteins, thus affecting the physicochemical properties of the film. This finding provides a theoretical reference for studying the mechanism of film formation of soybean protein emulsion films.

During oven drying of abalone muscle, microwave treatment was conducted at regular time intervals (0, 30, 60, 90 and 120 days). Abalone muscle digestion products (AMDP) were prepared by subjecting dried abalone to in vitro simulated digestion. Our aim was to investigate the effect of microwave treatment during the drying of abalone muscle on the in vitro and in vivo antioxidant activities of AMDP. The results showed that the half maximal inhibitory concentration (IC50) values of AMDP from fresh abalone muscle for scavenging capacity against hydroxyl (·OH) radicals, N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD) and 1,1-diphenyl-2-phenylhydrazine (DPPH) radical were 3.04, 15.18 and 21.12 mg/mL, respectively. The IC50 values for the scavenging of these three radical species decreased gradually with increasing the drying time of abalone muscle. After being fed AMDP from abalone muscle dried for 120 days, the body length of Caenorhabditis elegans increased from 768.90 to 1 034.62 μm, the head swing frequency increased from 206 to 281 times/min, and the life span was extended by 36.16% under normal conditions and by 59.41% and 38.48% under heat stress and oxidative stress conditions, respectively compared with the control group. Meanwhile, with prolonging the drying time of abalone muscle, the antioxidant enzyme activities, reduced glutathione (GSH) content and total antioxidant capacity of C. elegans fed AMDP increased, and the reactive oxygen species (ROS) content decreased. In summary, prolonging the drying time and using microwave treatment during the drying process could improve the antioxidant capacity of AMDP.

The patterns of changes in the physicochemical properties and volatile flavors of abalone muscle during drying at 50 ℃ and 65% relative humidity were investigated in this study. With an increase in drying time, the browning intensity and fluorescence intensity of both surface and internal muscles of abalone increased gradually, which started to decrease after reaching a peak on the 90th day. The contents of reducing sugar and lysine in the surface muscle were 3.11 mg/g and 2.60% after pretreatment, and decreased to 1.95 mg/g and 1.61% after 120 days of drying, respectively. High molecular mass polymers were observed in the electrophoretic pattern of abalone muscle after 30 days of drying. Fourier transform infrared spectra showed that the intensity of the characteristic absorption peaks (1 403 and 1 026 cm-1) of glycoproteins gradually enhanced with increasing drying time. The response values of the electronic nose sensors W1W (sulfides) and W2S (alcohols, aldehydes and ketones) increased, and the content of 1-octen-3-ol decreased while the contents of linalool and (E,E)-2,4-decadienal increased after 30 days of drying, as determined by gas chromatography-mass spectrometry (GC-MS). At the same drying time, the intensity of Maillard reaction in the surface muscle was weaker than that in the internal muscle.

BACKGROUND: Hairtail (Trichiurus haumela) surimi exhibits poor gelation properties and a dark gray appearance, which hinder its utilization in high‐quality surimi gel products. The effect of Pickering emulsions stabilized by myofibrillar proteins (MPE) on the gel properties of hairtail surimi has been unclear. In particular, the impact of MPE under NaCl and KCl treatments on the quality of hairtail surimi gels requires further elucidation. RESULTS: Pickering emulsions stabilized by myofibrillar proteins and treated with NaCl or KCl (Na‐MPE, K‐MPE) were added to hairtail surimi in amounts of 10–70 g kg−1. The addition of 50 g kg−1 Na‐MPE and K‐MPE improved the gel strength, textural properties, whiteness, and water‐holding capacity (WHC) of hairtail surimi. The relative content of β‐turn and β‐sheet in the surimi gels increased and the relative content of random coils and α‐helix decreased with the addition of oil. The addition of Na‐MPE and K‐MPE did not affect the secondary structure of surimi gels but stimulated the gelation of hairtail surimi gels. Hairtail surimi containing K‐MPE demonstrated similar performance in terms of hardness, microstructure, and WHC compared with the addition of Na‐MPE. CONCLUSION: The quality of hairtail surimi gels can be improved by the addition of Na‐MPE or K‐MPE. The K‐MPE proved to be an effective option for enhancing the properties of hairtail surimi gels at 50 g kg−1 to replace Na‐MPE. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Summary: After abalone muscle hot water extract (AHE) was digested in‐vitro, three components (F1, F2, and F3) were separated using the Sephadex G‐15 column, and the antioxidant activity and absorption across Caco‐2 cells were analysed. The result showed that the half‐maximal inhibitory concentrations of F2 for scavenging hydroxyl and ABTS radicals were 0.763 and 0.028 mg mL−1, respectively, which were lower than those of F1 and F3. Moreover, the Trolox equivalent antioxidant capacity was increased after the F2 was transported through the Caco‐2 cell‐monolayered Transwell chamber. The mass spectrometry analysis revealed that the transported samples contained oligopeptides (Leu‐Tyr, Gly‐Ala‐Ala, and His‐Gly‐Ser‐Ala), and the Leu‐Tyr displayed the highest antioxidant activity and transport rate. Overall, these results suggest that oligopeptides with high antioxidant capacities can be produced from AHE through a combination of in‐vitro digestion and absorption across Caco‐2 cells. [ABSTRACT FROM AUTHOR]

The effect of hydration degree on the structure of V-type starch and its thymol inclusion complex was investigated by encapsulating the thymol into V-type starch treated at different hydration times. The X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and differential calorimetry (DSC) were used to characterize V-type starch and its inclusion complexes, and the content of thymol was determined by gas chromatography. The results showed that the successful complexation between V-type starches and thymol was formed, and the inclusion complex exhibited an endotherm with peak temperature at 118 The inclusion complex after hydration for 72 h exhibited the largest endother- mic peak with AH of (7.31 ± 0.29) J/g. The XRD results showed that the crystallinity of V-type starch increased from 35.2% to 41.1% as the hydration time increased from 0 h to 72 h. The water in internal and external of V-type starch granule reached balance after 72 h of hydration, and the water coating on the surface of the granules gradually disap-peared and the particle roughness increased. The gas chromatography showed that the thymol content in the inclusion complex was positively correlated with hydration time. The research results provide a theoretical basis for the development of microcapsule wall materials of natural polymer materials, and are of great significance for the innovation and develop¬ment of high-value applications of flavor compounds. [ABSTRACT FROM AUTHOR]

BACKGROUND Application of fish skin collagen has received increasing attention due to mammalian derived diseases and religious limitations. Collagen fibril gel could be formed in vitro through the self‐assembly process. The present study investigated the effect of pH on the self‐assembly in vitro of acid‐solubilized collagen (ASC) from golden pompano skin by determining the turbidity, rheological viscoelasticity, network structure, gel strength, and thermal stability of collagen fibril gel. RESULTS: The isoelectric point of ASC was pH 5.27. The turbidity–time and rheological viscoelasticity results indicate that the collagen self‐assembly rate in vitro at pH 7.0 was the slowest. The rate was accelerated by increasing or decreasing the pH. Scanning electron microscopy images show that the fibril diameters of the collagen fibril gels and the collagenous fibril number in the collagen fiber increased with the pH. The gel strength of the collagen fibril gel prepared at pH 5.0 was 22.06 g and increased up to 220.46 g when pH increased to 8.0. No obvious peaks were observed in the differential scanning calorimetry curves of the collagen fibril gels prepared at pH 5.0, whereas high endothermic peak temperature (Tm) and enthalpy change (ΔH) were found in the collagen fibril gels prepared at pH 6.0–8.0. CONCLUSION: It is concluded that the physical properties of ASC fibril gels can be improved by increasing the fibril diameter controlled by pH. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Ethylene (ethene, C 2 H 4) was introduced into V-type crystalline starches (V-starches, namely V 6 - and V 7 -types) with different single helix contents (8.35–35.54%) by a solid encapsulation method. The morphological and structural properties of V-starches and their inclusion complexes (ICs) were characterized. The V-starches prepared with n -propanol (1-propanol) and ethanol showed a V 6 -type crystalline structure, whereas V-starches prepared with isopropanol (2-propanol) and t -butanol (2-methyl-2-propanol) exhibited V 7 -type crystalline structure. The ethylene concentrations in ICs followed the order of V n -propanol > V ethanol > V isopropanol > V t -butanol > V methanol , which appeared to be associated with the diameter of the V-starch single helices. Compared with V 7 -type starches, ethylene was more effectively encapsulated into V 6 -type starches with a smaller inner diameter. The controlled-release characteristics of ICs showed a diffusion-limited mechanism and first-order kinetics for ICs in different temperatures and relative humidities, respectively. Ethylene encapsulated in V 6 -type-ICs showed better controlled release kinetics than V 7 -type-ICs, except for V t -butanol -IC, which probably resulted from residual t -butanol in the single helices interfering with the release of ethylene. V-starches (particularly V 6 -type) appear to be effective gas storage and release systems for ethylene and this encapsulation technology should enable precisely-controlled and targeted applications of ethylene for food processing and agricultural applications. [ABSTRACT FROM AUTHOR]

Ethylene gas was introduced into annealed V-type crystalline starches (V-starches). The morphological and structural properties of the inclusion complexes (ICs) were characterized using scanning electron microscopy, light microscopy, X-ray diffractometry, and 13C solid-state nuclear magnetic resonance spectroscopy. The ethylene concentration in ICs annealed at 70 °C and 50% (v/v) ethanol increased from 8.0‐31.8% (w/w) to 18.1–49.6% (w/w). The controlled release characteristics of ICs were also investigated under various temperature and relative humidity conditions by fitting to the Avrami equation. ICs prepared with annealed V-starches were more stable in different storage environments, which may be due to well-formed helices with higher crystallinity and larger crystallite size. Thus, annealing is an important heat treatment technique with potential for material modification. • Ethylene gas was introduced into annealed V-type crystalline starches. • The ethylene concentration in ICs increased from 8.0–31.8% to 18.1–49.6%. • Annealing improved the stability of ethylene in different storage environments. [ABSTRACT FROM AUTHOR]

V-type starch carriers with different single helix contents were prepared using alcoholic-alkaline treatment followed by ethanol precipitation. Ethylene gas was entrapped into V-type starch carriers using a solid encapsulation method. The morphological and structural properties of inclusion complexes (ICs) were characterized using scanning electron and light microscopy, X-ray diffractometry, 13 C solid-state nuclear magnetic resonance (NMR) and Raman spectroscopy. Aqueous ethanol treatment resulted in swelling and aggregation of starch granules, and B-type diffraction reflections were either reduced or completely lost with evolution of V-type pattern. Ethylene concentrations in ICs vary from 15.4% to 23.6% (w/w), which was positively correlated with the single helix content in V-type starch carriers. The formation of ICs was confirmed by appearance of the characteristic peak associated with ethylene molecule on the 13 C NMR (123.14 ppm) and Raman (1630 cm −1 ) spectra. For the first time, we demonstrated that the single helix in V-type starch carrier determines the encapsulation capacity of ethylene. [ABSTRACT FROM AUTHOR]

A novel and simple process for the preparative extraction, separation, and purification of high-purity (–)-borneol and xanthoxylin, synchronously, from the leaves ofBlumea balsamifera(L.) DC was developed. Simultaneous distillation and extraction, silica gel column chromatography, and recrystallization were applied to the preparation. Two objective compounds with the purity of 98% were obtained, and the losses were minimal during the whole procedure. It is the first time that the preparation of high-purity (–)-borneol and xanthoxylin at the same time were achieved. [ABSTRACT FROM AUTHOR]

The effects of emulsified lard and transglutaminase (TGase) on the characteristics of threadfin bream surimi gels were investigated. Results showed that irrespective of TGase addition, the storage and loss modulus of surimi paste decreased with the increasing emulsified lard content during gel formation. The breaking force and deformation of surimi gels decreased from 857.33 g to 16.91 mm to 234.14 g and 8.44 mm respectively, after the addition of emulsified lard (2.5 g/100 g surimi). With further increase in the concentration of emulsified lard, the breaking force decreased, and the deformation remained almost unchanged. However, the weakening effect of emulsified lard was restrained by TGase. Regardless of TGase addition, the lightness, yellowness, and juiciness of surimi gels increased with the emulsified lard concentrations. The disulfide cross-linking among myosin heavy chains (MHCs) in surimi gels was inhibited by the emulsified lard, and the covalent cross-linking among MHCs was promoted by TGase. Emulsified lard and TGase could promote the hydrogen bonds among protein molecules in surimi gels. The compact and dense 3D gel network was destroyed by the added emulsified lard but protected in the presence of TGase. Therefore, high-quality surimi products could be produced under the combined action of emulsified lard and TGase. • Breaking force of surimi gel decreased with increasing emulsified lard content. • Weakening effect of emulsified lard on surimi gel was restrained by TGase. • Disulfide crosslinking among MHC in surimi gel was inhibited by emulsified lard. • Covalent crosslinking among MHC in surimi gel was promoted by TGase. • Compact and dense 3D gel network of surimi gel was destroyed by emulsified lard. [ABSTRACT FROM AUTHOR]

• Abalone muscle protein has high leucine and arginine. • Water-soluble fraction (WF) is rich in essential and umami amino acids. • The score of the first limiting EAA (tryptophan) in WF was more than 100%. • WF is more easily digested than the other fractions from abalone muscle. The chemical compositions and nutritional values of the water-soluble fraction (WF), myofibrillar protein (MP), and stroma protein (SP) from abalone muscle were investigated. The protein, carbohydrate, lipid, and ash contents of abalone muscle were 15.87, 6.36, 0.22, and 1.36 g/100 g, respectively. Most of the carbohydrates in the abalone muscle were released easily into water, and potassium was the most abundant mineral. WF and SP were rich in essential and umami amino acids, and all three fractions had high arginine contents. The essential amino acid index and predicted biological value of WF were 75.84 and 90.96, respectively. These values were considerably higher than those of MP and SP. Meanwhile, the predicted protein efficiency ratio of MP was the highest. Lysine was the first limiting essential amino acid (EAA) in MP and SP, and the score of the first limiting EAA (tryptophan) in WF was more than 100%. The in vitro protein digestibility of WF and SP was approximately 92% higher than that of MP. The in vivo experiments showed that WF was the easiest to digest. The nutritional value and high digestibility of WF can be claimed as a high-quality protein source based on the current findings. [ABSTRACT FROM AUTHOR]