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 Hydrogen sulfide (H2S) is recognized for its beneficial role in postharvest fruit and vegetable preservation. Postharvest goji berries are easy to mildew and rot which reduce the nutritional value, flavor, and shelf life. Hydrogen sulfide treatment could improve the quality attributes of postharvest goji berry (Lycium barbarum L.); however, it is not clear that the effects of H2S at the transcriptional level in postharvest goji berries. Our data revealed that the differentially expressed genes (DEGs) of fresh goji fruits after H2S treatment were different with different storage time. There were 523 DEGs in the three comparison groups after H2S treatment on the 2nd, 4th and 6th day of storage. In the pathway of KEGG metabolic function, most of the DEGs were conserved in carbohydrate metabolism, secondary metabolites biosynthesis, amino acid metabolism, lipid metabolism, energy metabolism, the metabolic pathways of terpenoids and polyketones. The genes in the phenylpropanoid biosynthesis, flavonoid biosynthesis, starch, and sucrose metabolism pathway were selected and validated by quantitative real-time PCR (qRT-PCR). Our results provide insights into the effect of H2S on postharvest goji berries at the transcriptional level and provide the basis for application of H2S as gas regulator for preservation of goji berry.

Abstract In order to improve separating aromatic/aliphatic group in adhesives or solvents of food packaging materials by pervaporation, an across linked graphene oxide (GO) framework were incorporated into waterborne polyurethane (WPU) membrane. The improved benzene solubility and expanded interlayer pathway of modified membrane have been gained based on three different reduced graphene oxide. Compared to P-phenylenediamine (PPD) and ethane-diamine (EDA) reducing agents, O-phenylenediamine (OPD) showed a relatively mild reducing ability and allowed GO to form a layer-to-layer lamella in the WPU matrix easily. When the dose of GO-OPD was 0.03%, the flux of GO-OPD/WPU membrane was 1.58 times of neat WPU or GO/WPU membranes, while the separation factor was slightly improved. The GO-OPD /WPU membrane also maintained good stability in the continuous pervaporation process of 2700 min.

Abstract Xuan-Mugua is a Chinese traditional fruit and is mainly preserved by air drying. To explore the effect of temperature on the drying property and quality of the fruits, they were sliced and dried at 60-90 °C. The results indicated that the drying time shortened from 150 to 80 min with the increasing temperature and the minimal time was found at 90 °C. The total phenolic content and antioxidant activity generally decreased by 5.09-18.27% at higher temperature (90 °C) and their maximums respectively appeared at 60 and 80 °C. Compared with the medium temperatures (60 and 70°C), the phenolic profiles changed obviously at higher temperatures (80 and 90 °C), and a transformation of chlorogenic acid was detected; besides, with the increasing temperature, the main phenolics including catechin and chlorogenic acid respectively decreased by 29.3% and 18.4%. Taking the above findings together, 70 °C should be the proper temperature to dry Xuan-Mugua fruits.

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.

Abstract The effects of micro comminution on the functional nutrients and antioxidant activity of quinoa cereal were investigated. The particle size distribution of quinoa cereal powder after micro comminution processing was investigated, as well as the nutritional and functional components and antioxidant characteristics. Simultaneously, correlations between antioxidant activity and product development and deep processing of quinoa cereal were investigated. The results indicate that: the fat, polysaccharide, and total phenol contents increased significantly (P < 0.05), while the total dietary fibre content decreased significantly (P < 0.05); the total antioxidant, DPPH, ABTS, and linoleic acid system contents of micro crushed quinoa oatmeal increased gradually, while the hydroxyl radical scavenging rate and TBA value decreased; when the grain size of micro crushed quinoa oatmeal was decreased. Micro crushing technique has the potential to boost quinoa cereal's nutritional content and antioxidant activity.