Abstract Despite the use of Maillard reaction products (MRPs) as food flavoring and coloring agents, they are also known to constitute acrylamide, heterocyclic amines, advanced glycosylation end products, and precursors of low molecular weight compounds. The very little is known about the toxicology of peony seed meal-derived MRPs. In this study, sub-chronic toxicity of peony seed meal derived MRPs was evaluated in Sprage-Dawley (SD) rats. Results showed that the body weight, hematology and serum biochemistry, organ coefficient and histopathology of SD rats with daily intake of peony seed meal-derived MRPs lower than 0.45 g/kg were not affected. After feeding with peony seed meal-derived MRPs for 13-weeks, there were no significant toxic effect on either male or female rats. This study provides a theoretical basis for the safety of MRPs derived from the reactants of enzymatic hydrolysis of peony seed meal.

Abstract Lactic acid bacteria are widely used as probiotics in food fermentation and exhibit various health-promoting properties. This study describes the effects of lactic acid bacteria (LAB) on the phenolic profiles, antioxidant activities, and enzyme inhibition prosperities of blueberry juice. Three different strains (Lactobacillus acidophilus JYLA-16, Lactobacillus plantarum JYLP-375, and Lactobacillus rhamnosus JYLR-005) were selected to ferment the blueberry juice at 37 °C for 48 h. After fermentation, the content of total phenolics and flavonoids increased. Meanwhile, the UPLC-LTQ-MS/MS system conducted the biotransformation of phenols during fermentation. LAB fermentation induced an upgraded trend of syringic acid, ferulic acid, erucic acid, rutin, catechin, epicatechin, and isoorientin. Pearson's correlation analysis revealed that phenolics' metabolism probably contributed to enhancing antioxidant activities. LAB also improved active ingredient retention and antioxidant capacities after in vitro simulated digestion. Finally, we investigated the α-glucosidase inhibitory and α-amylase inhibition of the fermented juice and found that LAB fermentation could improve the inhibition of these enzymes. This study indicated that LAB fermentation could be an efficient strategy for enhancing functional activities in blueberry juice by bio-transforming the phenolics.

Abstract The phenolic compounds in dried Lycium barbarum (LB) and L. barbarum meal (LBM) were extracted using ultrasonic method, reflux method and enzymatic method, and the composition, content of polyphenols and antioxidant abilities of the extracts were analyzed. 40 phenolic compounds were identified with HPLC-MS/MS, with 35 compounds detected from LB and 33 from LBM. 40 compounds were classified into phenolic acids and their derivatives, flavonoids, and their derivatives, lignanamides and other phenolic substances. Differences existed in samples extracted from different materials or under different extraction methods. It was explicitly observed that LB was higher than LBM in phenolic content. The phenolics in LB and LBM had significant antioxidant effects, with LBM extracts showing the higher antioxidant effect. This study compared the differences in polyphenols of L. barbarum and its meal, meanwhile explored the effects of different extraction methods, which could contribute to the exploitation of L. barbarum and its meal.

Abstract To investigate the effects of nitric oxide (NO) on the postharvest physiology and storage quality of Lycium barbarum, fruits were treated with different concentrations of sodium nitroprusside (SNP), which was used as NO donor. Results showed that SNP soaked at 0.6 mmol/L for 20 min could inhibit the changes during storage of L. barbarum. Particularly, the decay rate and weight loss rate were reduced, and the quality parameters of the fruit were increased. By comparing the above indicators, it was found that 0.6 mmol/L soaking for 20 min was more effective in preserving freshness than other concentrations. It was found that total chlorophyll and carotenoid contents were increased, soluble solids and solid acid ratio contents were decreased, ascorbic acid, total phenols and flavonoids contents were increased, and hydrogen peroxide (H2O2), superoxide anion (O2-), catalase (CAT) and malondialdehyde (MDA) contents were increased. The polyphenol oxidase (PPO) and peroxidase (POD) activities were decreased, and it was concluded that NO treatment improved the freshness of L. barbarum fruit and NO could be used as a postharvest preservative for L. barbarum fruit.