Effect of Winemaking on Phenolic Compounds and Antioxidant Activities of Msalais Wine.

Msalais wine (MW) is a popular traditional wine with the cultural characteristics of a specific Chinese ethnic group. In this study, phenolic profiles and antioxidant characteristics were identified using chromatographic analysis. A total of thirty-eight compounds, including eight furans, eleven phenolic acids, fourteen flavonoids, and five others, were identified via LC-MS/QTOF. It was found that catechin is the most abundant phenolic compound in MW, followed by epicatechin, gallic acid, caffeic acid, rutin, and p-coumaric acid. Winemaking had a significant influence on the levels of phenols and antioxidant activity. Condensed juice (CJ) displayed the highest phenol and antioxidant activity levels, while the levels were significantly decreased during the fermentation process and gradually stabilized thereafter during the aging process. A correlation analysis between the polyphenols in Msalais and their antioxidant capacity was performed to determine which molecules contributed more to the antioxidant capacity in a complex mixture of polyphenols. All of the phenolic compounds, except ferulic acid, showed good correlation with DPPH, ABTS, and CUPRAC. Among them, resveratrol had the strongest antioxidant capacity, although its concentration was very low. Catechin also had a strong antioxidant capacity, which was positively correlated with its concentration. This indicates that the antioxidant activity of Msalais is related to the number, type, and structure of polyphenols.

Phenolic characterization of fermented jujube puree by HPLC-MS/MS and their release during in vitro dynamic digestion.

Health benefits of fruit products fermented with probiotics are partially attributed to their increased contents of phenolic compounds. In this study, the effect of in vitro dynamic gastrointestinal digestion on the release of phenolic compounds and changes in the antioxidant activity of jujube puree fermented with Streptococcus thermophilus was investigated. Thirteen target phenolic compounds were characterized by high-performance liquid chromatography-tandem mass spectrometry. The recovery of this developed method ranged from 87.41% to 111.03%, and the limits of detection and quantification were low. Fermentation with Streptococcus thermophilus significantly increased the contents of most phenolic compounds in jujube puree. Fermentation reduced the decrease in the contents of most phenolic compounds in jujube puree during gastrointestinal digestion and, as a consequence improved the antioxidant capacity of digested fractions. These findings indicated that fermentation could increase the bioaccessibility of specific phenolics in jujube, as well as the antioxidant activity of this fruit.

Comprehensive comparative analysis of lipid profile in dried and fresh walnut kernels by UHPLC-Q-Exactive Orbitrap/MS.

Lipids are important nutrient components in walnuts. However, there has been a lack of comprehensive analysis of lipid composition in walnuts. Here, UHPLC-Q-Exactive Orbitrap/MS was employed to qualify and quantify the lipid compounds in seven walnut varieties from Xinjiang. A total of 390 lipids were tentatively identified, which were classified into six categories and 30 subcategories. GL and GP were the two most abundant lipids in all walnuts. Compared with fresh walnuts (FW), dried walnuts (DW) showed significantly higher lipids; in the 30 subcategories, DW showed decreases in some MGDG and PC while increases in LPC and MePC, all of which were related to the moisture content of walnuts. Totally, 128 lipids can be used as potential markers to distinguish FW from DW. Besides, the lipid profile varied among different varieties of walnut kernels. These findings may facilitate walnut variety selection and processing based on the characteristic lipids.

The effect of superfine tea powder addition on the acrylamide content of innovative Xinjiang nang products (tea nang).

In the present study, tea variety and proportions and tea nang production conditions were optimised to improve tea nang flavour, and dynamic changes in polyphenols and acrylamide content were determined. Orthogonal experimental design was adopted to optimise processing of low-acrylamide tea nang through a multi-index integrated evaluation method (MIEM) and a single-index balanced evaluation method (SBEM). Tea nang acrylamide content, polyphenol content and flavour quality were analysed by HPLC, colorimetry and sensory evaluation, respectively. A 180°C baking temperature, 7% matcha tea powder (MTP) content and 11 min of baking time were optimum. From the 11 kinds of tea from four categories, tea nang with 7% Biluochun tea powder exhibited the best comprehensive quality: decreased acrylamide, increased polyphenols, and the highest sensory scores (11.55 µg/kg, 6.1 mg/g and 92, respectively). This tea nang exhibited flavour senses of harmony, a strong tea flavour, and slight sweetness in back.

Identification and Antioxidant Activity of Flavonoids Extracted from Xinjiang Jujube (Ziziphus jujube Mill.) Leaves with Ultra-High Pressure Extraction Technology.

In this study, the ultra-high pressure extraction (UHPE) conditions for obtaining the maximum flavonoid yield from Xinjiang jujube (Ziziphus jujuba Mill.) leaves (XJL) were optimized by response surface methodology (RSM). Box⁻Behnken design (BBD) was applied to evaluate the effects of four variables (extraction temperature, pressure, time and liquid-to-solid ratio) on flavonoid yield. The results showed that the optimal flavonoid yield (25.45 ± 0.21 mg/g) was derived at 50.0 °C, 342.39 MPa, 11.56 min, and a liquid-to-solid ratio of 43.95 mL/g. Eight compounds were tentatively identified and quantified as kaempferol and quercetin glycosides with UPLC-ESI-MS. Compared to ultrasound-assisted extraction (UAE), UHPE can obtain higher concentrations of total flavonoids and stronger DPPH and ABTS radical-scavenging activities in a much shorter time. Therefore, UHPE is an alternative to UAE for obtaining flavonoids from XJL, which may be an optional method for large-scale industrial flavonoid extraction from XJL.

[Protective effect and underlying mechanism of cordycepin on non-alcoholic fatty liver in ob/ob mice].

This study is designed to investigate the protective effect and mechanism of cordycepin on non- alcoholic fatty liver in ob/ob mice. Twelve-week-old male ob/ob mice were divided into 5 groups according to their body weight and blood glucose, and C57BL/6J mice were used in the control group. The animals were orally administered with cordycepin for 7 weeks. Body weight and food intake were measured once a week. Blood were collected from ophthalmic venous and biochemical indexes were determined at the 2nd and 4th week. Insulin tolerance test was performed at the 5th week. After 7 weeks of administration, liver tissues were collected to determine the contents of triglycerides and total cholesterol, and pro-inflammatory cytokines. Liver histology was performed by hematoxylin-eosin and oil-red O staining. Total RNA were extracted from liver tissues and the levels of lipid metabolism-related and inflammation-related genes were detected by real time PCR. Cordycepin effectively reduced the blood lipids level and improved liver function. Nevertheless, it did not improve insulin resistance in ob/ob mice. Cordycepin significantly reduced the contents of triglycerides and cholesterol, and the levels of pro-inflammatory cytokines in liver tissues. Moreover, cordycepin remarkably suppressed the expression of genes related to lipids synthesis and inflammation. These results indicate that cordycepin may improve non-alcoholic fatty liver in ob/ob mice, and the underlying mechanism may be associated with decreased expression of genes related to lipids synthesis and inflammation.

Combination of UV-C treatment and Metschnikowia pulcherrimas for controlling Alternaria rot in postharvest winter jujube fruit.

The potential of using antagonistic yeast Metschnikowia pulcherrimas alone or in combination with ultraviolet-C (UV-C) treatment for controlling Alternaria rot of winter jujube, and its effects on postharvest quality of fruit was investigated. The results showed that spore germination of Alternaria alternata was significantly inhibited by each of the 3 doses (1, 5, and 10 kJ m(-2) ) in vitro. In vivo, UV-C treatment (5 kJ m(-2) ) or antagonist yeast was capable of reducing the percentage of infected wounds and lesion diameter in artificially inoculated jujube fruits, however, in fruit treated with combination of UV-C treatment and M. pulcherrima, the percentage of infected wounds and lesion diameter was only 16.0% and 0.60 cm, respectively. The decay incidence on winter jujube fruits treated with the combination of UV-C treatment and M. pulcherrima was 23% after storage at 0 ± 1 °C for 45 d followed by 22 °C for 7 d. None of the treatments impaired quality parameters of jujube fruit. Thus, the combination of UV-C radiation and M. pulcherrima could be an alternative to synthetic fungicides for controlling postharvest Alternaria rot of winter jujube.