Gongnian Xiao

Antioxidant Activity of Isothiocyanate Extracts from Broccoli

Isothiocyanates (ITCs) extracts were prepared from fresh broccoli. Their antioxidant properties were evaluated by using the in vitro bioassays, including superoxide anion radical (O2·−), hydroxyl radical (HO−) and 2,2-diphenyl-1-picrylhydracyl (DPPH·) radical-scavenging methods, lipid peroxidation assay, and reducing power assay. The ITCs extracts exhibited significant dose-dependent antioxidant activities (P<0.01). Its antioxidant-stability was affected by temperature and storage condition, although it was more stable than vitamin C (Vc). GC-MS identified sulforaphane in the ITCs extracts. The antioxidant activity of sulforaphane was approximately one tenth to one fifth of that of Vc. Sulforaphane was experimented to be one of dominating contributors to antioxidant capacity of ITCs extracts. However, there was no direct antioxidant activity found for benzyl isothiocyanate (BITC) in vitro. Therefore, it could be concluded that the general group (NCS) was not the essential part for the antioxidant activity of sulforaphane. It is suggested that the ITCs extracts from broccoli can be developed into a promising food additive for healthy food.

Microbial transglutaminase enhances antioxidant activity of yogurt through altering pattern of water‐soluble peptides and increasing release of amino acids

Microbial transglutaminase increases antioxidant capacity of yogurt by altering peptides pattern and increasing release of free amino acids.

Antioxidant Capacities of Fractions of Bamboo Shaving Extract and Their Antioxidant Components

This research was conducted for evaluation of antioxidant activities of four fractions from bamboo shavings extract (BSE) and their antioxidant components. The antioxidant capacities of BSE and four fractions on ABTS, DPPH, FRAP and total antioxidant capacity assays exhibited the following descending order: DF > n-butanol fraction (BF) > BSE ≈ ethyl acetate fraction (AF) > water fraction (WF). Among the identified phenolic compounds, caffeic acid exhibited the highest antioxidant capacities on DPPH, FRAP and total antioxidant capacity assays. An extremely significant positive correlation between the antioxidant activities with the contents of total flavonoids, total phenolic acids, or total phenolics was observed in this study. The result indicated that the bamboo shaving extract and its solvent fractions could act as natural antioxidants in light of their potent antioxidant activities.

Secondary structures and their effects on antioxidant capacity of antioxidant peptides in yogurt

ABSTRACT The pH, thermal, urea, and trifluoroethanol treatments were used to denature yogurt antioxidant peptides, and their antioxidant capacities and secondary structures were analysed. Results showed that yogurt peptides treated at pH 6.0 or above 50°C exhibited higher antioxidant activity than the control, whereas trifluoroethanol treatment resulted in a reduction and urea treatment held invariability. Peptide secondary configuration analyses revealed that these treated peptides significantly decreased their α-helical conformation but enhanced the β-sheet presence as well as an obvious alteration on β-turn and random coil structures. These peptide conformation alterations contributed to their antioxidant property increase.

Effect of Vacuum Soaking on the Properties of Soybean (Glycine max (L.) Merr.)

Abstract The water absorption of soybeans (Glycine max (L.) Merr.) during soaking is directly related to their textural characteristics and grinding properties during processing. In this study, we determined the effects of vacuum soaking on the absorption of water and salt solutions by soybeans. We also analyzed the textural characteristics and grinding properties of soybeans soaked under atmospheric and vacuum pressures (0.02–0.08 MPa) for 8 and 16 h. The results showed that vacuum soaking promoted the absorption of water and NaHCO3 solution. Vacuum soaking also decreased the hardness of soybeans. Soaking under vacuum significantly shortened the soaking time required for soybeans. Additionally, the protein content was higher in soymilk made from vacuum-soaked soybeans than in soymilk made from soybeans soaked under atmospheric pressure.