The effects of mulberry polyphenols on the digestibility and absorption properties of pork myofibrillar protein in vitro.

The objective of the present study was to explore the effect of mulberry polyphenols on the digestibility and absorption properties of myofibrillar protein (MP) in vitro. MP was extracted from the Longissimus et thoracis muscle of 18 different pig carcasses and the MP-mulberry polyphenols complex was prepared. The antioxidant activity of digestive juice, degradation of both MP and polyphenols, and the metabolism of MP and the MP-polyphenols complex by intestinal microbial activity during digestion and fermentation in vitro were compared. The results showed that mulberry polyphenols significantly affect the digestibility of MP and the antioxidant activity of digestive juices during digestion (P < 0.05). After the modification of the polyphenols, the hydrolysis of MP increased from 55.4% to 64.0%, and the molecular weight of protein digestion product significantly decreased (P < 0.05). The scavenging rates of 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl in the final digestive juice were 350.1 µmol Trolox/mg protein and 34.0%, respectively, which were 0.34 and 0.47-fold higher than those of the control (P < 0.05). Furthermore, the release and degradation of phenolic compounds mainly occurred during intestinal digestion, and polyphenols that reached the colon after digestion, through the fermentation of intestinal microorganisms in vitro, enriched Lactobacillus and promoted the production of short-chain fatty acids which has obvious potential to improve intestinal health.

Enhancement of water barrier and antimicrobial properties of chitosan/gelatin films by hydrophobic deep eutectic solvent.

Biodegradable chitosan/gelatin (CS/GEL) films have attracted attention as food packaging, but the poor water sensitivity and functional limitations of these films should be addressed. In this study, the hydrophobic deep eutectic solvent (DES, 0-15 %) consisting of thymol and octanoic acid was used to improve the water resistance and antibacterial performance of the CS/GEL composite films. FTIR and SEM analyses revealed a strong interaction between the CS/GEL matrix and DES. The films blended with DES showed increased water contact angle values and thermal stability. Furthermore, the addition of DES resulted in a significant increase in the elasticity and decrease water vapor transmission rate (WVTR). The CS/GEL films blended with 9% DES showed a 38.5% decrease in WVTR compared to those without DES. Additionally, the DES-containing film displayed good antibacterial activity against Staphylococcus aureus and Escherichia coli. Overall, the CS/GEL-DES composite films are expected to contribute an improvement to food packaging.

Improved physicochemical stability and bioaccessibility of astaxanthin-loaded oil-in-water emulsions by a casein-caffeic acid-glucose ternary conjugate.

In this study, the influence of casein-caffeic acid-glucose ternary conjugate (CSC) on the physicochemical properties and bioaccessibility of astaxanthin-loaded emulsion was investigated and compared with sodium caseinate (CSN), a synthetic emulsifier commonly used in the food industry. The CSC-stabilized emulsion exhibits droplet characteristics similar to CSN-stabilized emulsion, and can effectively resist the external forces that lead to the phase separation of the emulsion. Although phase separation also occurred at pH 4.0, CSC emulsion had a wider range of pH stability (pH 3.0, 5.0-8.0) and higher salt ion stability than CSN emulsion. Furthermore, CSC-stabilized astaxanthin emulsions showed better astaxanthin protection under different heat treatment conditions and storage temperatures compared with CSN. After 28 days of storage at 4 °C, astaxanthin residues in the CSC-stabilized emulsion reached 92.37 %. The bioaccessibility of astaxanthin in CSC-stabilized emulsion was 26.21 %, much higher than that in CSN (6.47 %). This research study provides a platform for designing astaxanthin-fortified food or beverage systems to achieve better stability and delivery to target sites.

Influence of Gelatin-Chitosan-Glycerol Edible Coating Incorporated with Chlorogenic Acid, Gallic Acid, and Resveratrol on the Preservation of Fresh Beef.

Chlorogenic acid (CA), gallic acid (GA), and resveratrol (RES) were added to a gelatin (GEL)-chitosan (CHI)-glycerol (GLY) edible coating, and their effects on the coating of fresh beef preservation were investigated. The results revealed that CA had the most significant improvement effect on fresh beef preservation. The combination of GEL-CHI-GLY-CA preserved the color of the beef better and delayed the increase of the total volatile base nitrogen, even though its total phenolic content decreased at a faster rate during beef preservation. GA also improved the preservation effect as on the 12th day of storage, the beef samples treated with GEL-CHI-GLY-GA had the lowest thiobarbituric acid reactive substances (0.76 mg Malondialdehyde (MDA)/kg) and total viable count (6.0 log cfu/g). On the whole, though RES showed an improvement on beef preservation, the improvement was not as good as the other two polyphenols. After 12 days of storage, the beef samples treated with GEL-CHI-GLY-RES had a higher pH value (6.25) than the other two polyphenol treatmed groups. Overall, the three polyphenol-added combinations increased the shelf life of beef by approximately 3-6 days compared to the control group (treated GEL-CHI-GLY with distilled water).

Comparison of Oil Content and Fatty Acid Profile of Ten New Camellia oleifera Cultivars.

The oil contents and fatty acid (FA) compositions of ten new and one wild Camellia oleifera varieties were investigated. Oil contents in camellia seeds from new C. oleifera varied with cultivars from 41.92% to 53.30% and were affected by cultivation place. Average oil content (47.83%) of dry seeds from all ten new cultivars was almost the same as that of wild common C. oleifera seeds (47.06%). New C. oleifera cultivars contained similar FA compositions which included palmitic acid (C16:0, PA), palmitoleic acid (C16:1), stearic acid (C18:0, SA), oleic acid (C18:1, OA), linoleic acid (C18:2, LA), linolenic acid (C18:3), eicosenoic acid (C20:1), and tetracosenoic acid (C24:1). Predominant FAs in mature seeds were OA (75.78%~81.39%), LA (4.85%~10.79%), PA (7.68%~10.01%), and SA (1.46%~2.97%) and OA had the least coefficient of variation among different new cultivars. Average ratio of single FA of ten artificial C. oleifera cultivars was consistent with that of wild common C. oleifera. All cultivars contained the same ratios of saturated FA (SFA) and unsaturated FA (USFA). Oil contents and FA profiles of new cultivars were not significantly affected by breeding and selection.

Highly efficient and enzymatic regioselective undecylenoylation of gastrodin in 2-methyltetrahydrofuran-containing systems.

Highly efficient and regioselective acylation of pharmacologically interesting gastrodin with vinyl undecylenic acid has been firstly performed through an enzymatic approach. The highest catalytic activity and regioselectivity towards the acylation of 7'-hydroxyl of gastrodin was obtained with Pseudomonas cepacia lipase. In addition, it was observed the lipase displayed higher activity in the eco-friendly solvent 2-methyltetrahydrofuran-containing systems than in other organic solvents. In the co-solvent mixture of tetrahydrofuran and 2-methyltetrahydrofuran (3/1, v/v), the reaction rate was 60.6 mM/h, substrate conversion exceeded 99%, and 7'-regioselectivity was 93%. It was also interesting that the lipase-catalyzed acylation couldn't be influenced by the benzylic alcohol in gastrodin. However, pseudomonas cepacia lipase displayed different regioselectivity towards gastrodin and arbutin.