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Polyphenol oxidase (PPO) is one of the most important factors affecting the browning of fresh-cut fruit and vegetable products. In this research, the effect of aromatic hydrosol on the activity of PPO and its biological antioxidant effect were studied. Aromatic hydrosol extracted from 12 kinds of aromatic plants by steam distillation all inhibited the activity of PPO. Eight of the 12 aromatic hydrosols had a significant scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation, and 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (PTIO) radicals. Total antioxidant capacity assay showed that they had strong antioxidant activity. Analysis by electronic nose and gas chromatography-mass spectrometry (GC-MS) showed that terpenoids and aromatic compounds were the major volatile components of aromatic hydrosol. The efficacy of aromatic hydrosol was evaluated in preserving the quality of fresh-cut mushrooms (Agaricus bisporus). The results showed that compared with the control group, the PPO activity in mushrooms treated with aromatic hydrosol was inhibited, and the increase in browning index (BI) was delayed. In addition, total phenol content, hardness, mass loss and total microbial load were effectively controlled. These results indicate that aromatic hydrosol treatment has a positive effect on maintaining the quality of fresh-cut mushrooms.

Carboxymethyl cellulose and β-cyclodextrin stabilized water-wrapped tea seed oil Pickering emulsion was prepared using the high-speed shearing method. The particle size test and microstructure observation showed that the average particle size of the emulsion droplet decreased while the apparent viscosity, viscoelasticity, and stability increased with the increase in the concentration of carboxymethyl cellulose, β-cyclodextrin, and oil fraction. The droplet size of the emulsion increased slightly after heating from 50 °C to 90 °C, and the thermal stability of the emulsion increased after 50 °C treatment. pH exhibited little effect on emulsion stability. Carboxymethyl cellulose enhanced the adsorption of cyclodextrin colloidal particles on the water-oil interface via non-covalent interaction, steric hindrance, and drainage, which improved the viscosity of the emulsion. Therefore, it can be seen that the combination of carboxymethyl cellulose and β-cyclodextrin can significantly increased the stability of emulsions. [ABSTRACT FROM AUTHOR]

AbstractSynthetic shampoos that include several chemical components are available in the market. However, the safety and impact of chemical additives are under discussion, because their long-term use may result in hair dryness, scalp irritation, and hair loss. To develop a formulated shampoo as an alternative to synthetic shampoos, this study focused on fabricating a completely natural shampoo comprising Gleditsia sinensis Lam extract (GSW) and Sapindus mukurossi extract (SMW), Gleditsia polysaccharides (SP), cod skin collagen peptide (CSCP), and an essential oil. The influence of the interaction between GSW and SMW, SP, and CSCP components on the foaming performance was investigated using the Ross–Miles method, and the antioxidant activity was analyzed using free radical scavenging. The formulated shampoos were prepared using low-energy emulsification, and their surface tensions were determined using the Wilhelmy plate method. The antibacterial and antifungal activities of the shampoos were revealed by determining the minimum inhibitory and bactericidal concentrations. An interaction assay showed that GSW and SMW exhibited synergistic effects on foaming performance, and SP showed an improved foam stability of GSW. In addition, the antioxidant properties of the mixture (GSW and CSCP) exhibited cooperation. Finally, the optimal formulation of shampoo was GSW (20 wt%) and SMW (20 wt%), CSCP (0.5 wt%), and SP (2 wt%). The shampoo exhibited good foaming performance and decontamination and strong antioxidant, antibacterial, and antifungal activities. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effects of dietary supplementation of 0%, 0.2%, 0.35%, and 0.5% cinnamon essential oil on growth performance, fatty acid, and fillet quality of tilapia (Oreochromis niloticus). The results of growth experiments showed that the weight gain rate linearly and quadratically increased with increasing cinnamon essential oil doses (p < 0.05). The results of fatty acids experiments showed that the addition of essential oil significantly decreased the saturated fatty acids levels from 36.67% to 30.82% and increased the polyunsaturated fatty acids (PUFA) levels from 24.55% to 46.89%; especially, the n − 3 PUFA of 0.5% essential oil treatment showed the highest levels. Moreover, the n − 6 PUFA of 0.2% essential oil treatment were increased from 22.17% to 32.99%. The results of fillet quality experiments showed that the hardness and cohesiveness were linearly and quadratically increased with the increasing essential oil doses on days 4 and 7, respectively. The b* values linearly and quadratically decreased as the doses increased on day 7 (p < 0.05). The total volatile basic nitrogen levels were quadratically decreased with increasing cinnamon essential oil doses on day 7 (p < 0.05). In general, it can be concluded that cinnamon essential oil presented positive effects on the growth, nutritive values, and meat quality in tilapia. [ABSTRACT FROM AUTHOR]

Summary: Plant essential oils have great potential to become a new generation of marine fish preservatives, and the key to the application of essential oil in fresh‐keeping is to improve its cost performance. In this study, the combined effect of 0.008 g/mL lemongrass essential oils and 0.01 g/mL cinnamon essential oils with different concentration (0, 0.005, 0.01, 0.03, 0.05 g/mL) of tea polyphenols on the antioxidant activity and antimicrobial activity in vitro, and application in marine fish preservation was studied. The in vitro tests showed that the combination of essential oils with tea polyphenols increased the antioxidant and antimicrobial activities compared with the essential oils or tea polyphenols alone. During the preservation of the marine fish Dusky Spinefoot, the combination of essential oils with tea polyphenols slightly inhibited microbial growth, but greatly reduced the visible decay on the surface of fish flavour deterioration and biogenic amine production. Antimicrobial activities were also observed in films prepared combining essential oil and tea polyphenols. These combined effects are meaningful and provide prospects for expanding the application of essential oil and developing a new hurdle technology for marine fish storage. [ABSTRACT FROM AUTHOR]

Essential oils (EOs) have good natural antioxidant and antimicrobial properties; however, their volatility, intense aroma, poor aqueous solubility, and chemical instability limit their applications in the food industry. The encapsulation of EOs in β-cyclodextrins (β-CDs) is a widely accepted strategy for enhancing EO applications. The complexation of cinnamon essential oil (CEO) with five types of β-CDs, containing different substituent groups (β-CD with primary hydroxyl, Mal-β-CD with maltosyl, CM-β-CD with carboxymethyl, HP-β-CD with hydroxypropyl, and DM-β-CD with methyl), inclusion process behaviors, volatile components, and antioxidant and antibacterial activities of the solid complexes were studied. The CEOs complexed with Mal-β-CD, CM-β-CD, and β-CD were less soluble than those complexed with DM-β-CD and HP-β-CD. Molecular docking confirmed the insertion of the cinnamaldehyde benzene ring into various β-CD cavities via hydrophobic interactions and hydrogen bonds. GC-MS analysis revealed that HP-β-CD had the greatest adaptability to cinnamaldehyde. The CEO encapsulated in β-, Mal-β-, and CM-β-CD showed lower solubility but better control-release characteristics than those encapsulated in DM- and HP-β-CD, thereby increasing their antioxidant and antibacterial activities. This study demonstrated that β-, Mal-β-, and CM-β-CD were suitable alternatives for the encapsulation of CEO to preserve its antioxidant and antibacterial activities for long-time use. [ABSTRACT FROM AUTHOR]

In order to improve the antibacterial ability of the vapour phase of cinnamon essential oil, the inhibitory effects of the aromatic vapours generated by four kinds of cinnamon essential oil vapour-producingmethods against Staphylococcus albicans were investigated. It was found that the influences of the vapour-producing methods on the antibacterial effects followed a certain trend.Among them, the order of the minimum inhibitory concentration (MIC) was as follows: spray atomization > water bath heating > natural volatilization > combustion; and the order of the minimum bactericidal concentration (MBC) was: water bath heating > spray atomization > natural volatilization > combustion. The electronic nose technique was used to distinguish the gas components at the minimum bactericidal concentrations of the four kinds of vapour-producing methods. Headspace solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was used to analyze further the compositions of the aromatic vapours. The results showed that the relative contents of the components detected in the vapours generated by different vapour-producing methods differed greatly. Among them, 15 kinds of components with their relative contents higher than 1%were detected in the vapour produced by the water bath heatingmethod, with the relative contents of individual terpenes up to 29.76%; the spray atomization forced the generation of cinnamaldehyde at a higher relative content (up to 74.26%). It can be seen that when the vapour-producing method applied to cinnamon essential oil was changed, the composition of the gas aromatic vapour was altered, which affected the subsequent antibacterial effect against Staphylococcus albicans. Among them, spray atomization exhibited the greatest inhibitory effect, whilst the water bath heatingmethod led to the greatest bactericidal effect. [ABSTRACT FROM AUTHOR]

The emulsifying and antioxidant properties of chicken protein hydrolysates for the physical and oxidative stabilization of chicken oil‐in‐water emulsion were investigated. The chicken protein pepsin hydrolysates obtained at reaction temperature of 33℃, 1.8% enzyme addition, liquid–solid ratio of 5:1, and reaction time of 4h, showed the DPPH radical scavenging rate of 92.12% and emulsion stability index of 0.07. The hydrolysate exerted significantly improved antioxidant activity and emulsion ability compared to the native chicken protein. The amino acid composition analysis indicated that the contents of hydrophobic amino acids including tyrosine, phenylalanine, and tryptophan were increased after hydrolysis, which contributed to the higher hydrophobicity and antioxidant activity of chicken hydrolysates. The results suggested that the chicken protein hydrolysates could be used as an alternative protein emulsifier for the production of oxidatively stable chicken oil‐in‐water emulsion. [ABSTRACT FROM AUTHOR]

The current popularity of soy proteins, due to their low cost and high nutritional value, continues to drive soy research and commercial development of new food products. However, the poor emulsifying properties have limited the application of soy proteins in emulsion-based food products. Modification of soy proteins by enzymatic hydrolysis for improved functionalities is a well-accepted and safe method, but soy proteins are resistant to enzymatic hydrolysis due to their compact structures that protect many of the peptides bonds. Recently, it has been reported that microfluidization treatment can disrupt the quaternary and tertiary structure of globular proteins and break up protein aggregates, which may cause the exposure of more cleavage sites. However, limited information is available concerning the effects of microfluidization pretreatment on the enzymatic hydrolysis pattern of soy proteins or on the emulsifying properties of its hydrolysates. Hence, the objective of this work was to study the effects of combining microfluidization pretreatment and controlled enzymatic hydrolysis using Papain on the emulsifying properties of soy protein isolates (SPI). Microfluidizaiton pretreated SPI (MSPI) was prepared using a microfluidizer at a specific pressure level of 120 MPa. Papain was used as protease for the preparation of SPI hydrolysates (SPIH) and MSPI hydrolysates (MSPIH). Oil-in-water emulsions (20% v/v sunflower oil, 20 g/L protein sample, pH=7.0) were formed by SPIH and MSPIH with various DH (degree of hydrolysis). And the analysis of mean droplet sizes and microstructures of these emulsions showed that emulsions formed by control SPI and SPIH were unstable to bridging flocculation, suggesting their poor emulsifying capability. This findings may be explained by the fact that there were insufficient soluble protein with high surface activity existed in control SPI and SPIH. In contrast, some MSPIH (DH was 1.3%-1.7%) showed that the emulsifying capability and emulsions stabilization against bridging flocculation were markedly improved. Compared with control SPI and SPIH (0.6% DH), MSPIH (1.7% DH) was capable of producing a stable fine emulsion (d43≈1.6 μm) at a lower concentration (30 g/L), suggesting its better emulsifying capability. Composition of subunits, protein solubility (NSI), surface hydrophobicity (H0) and molecular weight distribution of SPIH and MSPIH have been measured in order to study the underpinning mechanisms of improving emulsifying capability for SPIH and MSPIH. The analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles of different hydrolysates showed that microfluidization pretreatment could significantly improve the enzymatic accessibility of subunits of α-7S and A-11S in SPI that were resistant to Papain hydrolysis. As a result, compared with SPIH, MSPIH showed a stronger increase in protein solubility and a more moderate change in surface hydrophobicity. Therefore, when DH was 1.3%-1.7%, MSPIH not only had greatly increased protein solubility (NSI was 51.3%-58.2%), but also retained sufficiently high surface hydrophobicity (H0 was 1021.7-1614.2). These finding suggested that after microfluidization pretreatment, more soluble polypeptides with high surface activity were produced during Papain hydrolysis in MSPIH, which may be the main cause for the increase in their emulsifying capability. Moreover, compared with control SPI and SPIH (0.6% DH), MSPIH (1.7% DH) showed a smaller molecular weight distribution mainly around 11.3 kDa, and probably had a better flexibility of protein structure, which benefited for the adsorption and unfolding of protein molecule at the oil-water interface and for preventing the bridging flocculation of droplets. In summary, this study demonstrates that modified soy proteins can be an excellent emulsifying agent for food and other applications. It also demonstrates that combining microfluidization pretreatment and controlled enzymatic hydrolysis can be an effective way for the functionality modification of globular proteins. [ABSTRACT FROM AUTHOR]

A rapid and simple capillary electrophoresis (CE) coupled with chemiluminescence (CL) detection was proposed for analysis of nicotinamide. This method was based on the inhibitory effect of nicotinamide to CL reaction of luminol-K3Fe(CN)6 in alkaline aqueous solution. Under the optimal conditions, nico-tinamide can be assayed in the range of 0.01-10.0 μM with a limit of detection of 3.0 nM. The whole analysis process can be completed within 11 min. The relative standard deviations of the signal intensity and the migration time were 3.0% and 1.5% for a standard sample at 0.1 μM, respectively. The presented CE-CL method was successfully applied to the determination of nicotinamide in yogurt, human urine and plasma samples. [ABSTRACT FROM AUTHOR]

According to the features of crankshaft and camshaft sensor signals, a signal coding-based timing synchronization scheme is proposed. By using layered and modular designs, a timing synchronization software is developed based on the enhanced time processing unit (eTPU) in MPC 563, realizing timing synchronization control. The test results show that the scheme is correct with accurate control, achieving expected goal. [ABSTRACT FROM AUTHOR]

Essential oils have been recognized for their strong antibacterial property, making them an innovative approach for preserving meat. However, their chemical instability and direct impact on meat proteins limit their application. To overcome these limitations, various loading systems have been explored. This study aimed to compare the effect of cinnamon essential oil (CEO) loaded in a liposome and emulsion system on the proteolysis of minced pork and to evaluate the advantages of each delivery system in preventing microorganism-induced quality deterioration of meat. Minced pork treated with CEO-liposomes exhibited lower pH, total volatile basic nitrogen (TVB-N), and total viable count (TVC) values than CEO-emulsions and provided better protection against microorganisms. SDS-polyacrylamide gel electrophoresis (PAGE) analysis confirmed that CEO-liposome was more effective in protecting proteins from degradation. Moreover, CEO-liposome produced lower amount of bitter amino acids and harmful biogenic amines. Antibacterial mechanisms indicated that CEO-liposome exhibited a stronger inhibitory effect against major spoilage bacteria in meat products by increasing cell membrane permeability. The membrane damage was further supported by an increase in conductivity and the leakage of nucleic acids. Compared to the CEO-emulsion system, CEO-liposome emerged as an effective preservative for minced pork. These results provided important theoretical support for using a bioactive compound delivery system to prevent microorganism-induced quality deterioration in meat., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wu, Zhang, Chai, Wang and Duan.)

This study aimed to determine the antibacterial mechanism of cinnamaldehyde fumigation in Escherichia coli ( E. coli ). Through vapour fumigation, cinnamaldehyde was confirmed to exhibit effective antibacterial activity against E. coli. The minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) were 0.25 μL/mL and 0.5 μL/mL, respectively. Based on transmission electron microscopy, the wrinkled bacterial cells observed after fumigation could be related to the leakage of intracellular substances. Laser tweezers Raman spectroscopy revealed changes in the main chain of proteins, the hydrogen bond system and spatial structure, and single- and double-stranded DNA breaks. In addition, breakage of the fatty acyl chain backbone was found to affect the vertical order degree of the lipid bilayer and cell membrane fluidity, thereby inhibiting the growth of E. coli . Overall, our findings indicate that cinnamaldehyde fumigation inhibits E. coli growth by inducing changes in intracellular biological macromolecules.

Objective: To know food contamination and genetic diversity of Campylobacter jejuni in four provinces of South China, and to provide data for C. jejuni-associated foodborne disease prevention and control., Methods: According to the national standard and the most probable number (MPN) method, we detected the contamination of C. jejuni from 558 food samples including vegetables, meat product, cooked food, seafood, frozen food, dairy product and edible fungi during 2011 and 2012. The isolates were used to detect 12 virulence-associated genes with PCR methods and construct ERIC-PCR fingerprints., Results: Fourteen positive samples were determined from 558 samples, and all positive samples come from meat product samples. The average value of MPN of positive samples was 8.77 MPN/g. Virulence-associated gene analysis reveals that more than 50% of the C. jejuni isolates had at least 9 virulence genes. Interestingly, virB11 gene was not found and the genes of pldA and wlaN were 14.30% in all isolates. Total of 15 C. jejuni isolates could be divided into 10 genotypes belonging to 3 clusters by ERIC-PCR fingerprints., Conclusion: Meat product was the main source of C. jejuni food contamination in four provinces of South China. More control measures must be taken to avoid C. jejuni contamination.

In this paper, effects of phytohormones on growth and DHA production by Thraustochytrium roseum MF2 were studied. Results showed that phytohormones had significant affect on growth and DHA production by T. roseum MF2. GA could promote the synthesis of DHA, and BA could accelerate the growth of T. roseum MF2, so the combination of GA and BA could increase DHA yield. The maximum DHA yield of 982mg/L was observed with 2mg/L GA and 3mg/L BA in medium.