Bini Wang

Distribution of Phenolic Acids in Different Tissues of Jujube and Their Antioxidant Activity

Free, esterified, glycosided, and insoluble-bound forms of eight phenolic acids in pulp, seed, and peel of jujube are separated and quantified by high performance liquid chromatography with electrochemical detection (HPLC-ECD). In the whole jujube, p-hydroxybenzoic and cinnamic acids are the most abundant phenolic acids. All quantified phenolic acids are mainly present in jujube peel. Phenolic acids in seed and peel are present in the insoluble-bound form, while, in pulp in the glycosided form, the glycosided and insoluble-bound phenolic acid fractions in jujube pulp represent the highest total phenolic content and the strongest antioxidant activity determined by DPPH and FRAP assays. Our results show that most phenolic compounds with antioxidant activity in different tissues of jujube are present as the glycosided and insoluble-bound forms.

Protective effects of buckwheat honey on DNA damage induced by hydroxyl radicals

To understand the antioxidant properties of buckwheat honeys, we investigated their antioxidant effects on hydroxyl radical-induced DNA breaks in the non-site-specific and site-specific systems, the physicochemical properties, antioxidant activities (1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical scavenging activity, chelating, and reducing power assays), total phenolic content and individual phenolic acids were also determined. Total phenolic content of buckwheat honeys ranged from 774 to 1694 mg PA/kg, and p-hydroxybenzoic and p-coumaric acids proved to be the main components in buckwheat honeys. All the buckwheat honey samples possess stronger capability to protect DNA in the non-site-specific systems than in the site-specific systems from being damaged by hydroxyl radicals. In the non-site-specific and site-specific system, buckwheat honeys samples prevented ()OH-induced DNA breaks by 21-78% and 5-31% over control value, respectively.

Extraction Optimization and Functional Properties of Proteins from Kiwi Fruit(Actinidia chinensis Planch.) Seeds

Kiwi fruit (Actinidia chinensis Planch.) seed proteins, as solid wastes in food industries, remain underutilized. Response surface methodology for kiwi fruit seed proteins extraction optimization results showed that pH and solid/liquid ratio were the most important factors affecting the yield. Maximum yield (613.7 g/kg total protein) was obtained when temperature, pH, extraction time, and solid/liquid ratio were 33.9°C, pH 9.14, 49.2 min, and 1:8.4 (w/v), respectively. Kiwi fruit seed protein had more proteins or peptides with low molecular weights, showing a better digestibility. Functional properties results indicated that kiwi fruit seed protein as potential ingredients could be used as a substitute for soybean protein for food processing.

Removal of Chloramphenicol by Macroporous Adsorption Resins in Honey: A Novel Approach on Reutilization of Antibiotics Contaminated Honey

The effects of different steps in honey production on chloramphenicol (CAP) levels and CAP removal from honey using macroporous adsorption resins (MARs) were investigated in this study. CAP residues in honey were quantified by enzyme-linked immunosorbent assay after each processing step including preheating, filtration, vacuum concentration and pasteurization. Vacuum concentration contributes the most reduction of CAP level (9.9%). Meanwhile, 5 types of MARs (including LSI-1, LSI-2, LSI-3, LS-803, and LS-903) were used in CAP adsorption. The results showed that LS-803 resin had higher adsorption rate of 86% than other resins in removing CAP from honey, and its optimal adsorption time and temperature were 40 min and 55 °C, respectively. The treated honey could be used as feed additive or biomass energy. Therefore, it would be a novel approach to reutilization of antibiotics contaminated honey.