In this paper, composite nanoparticles consisting of soybean peptide aggregates (SPA) and (-)-epigallocatechin gallate (EGCG) were successfully prepared by ultrasonic treatment and its particle size, zeta potential, fluorescence spectrum and X-ray diffraction pattern were measured. Furthermore, the droplet size and oxidation stability of emulsions stabilized with SPA or the composite nanoparticles were evaluated. The results showed that ultrasound and EGCG had a synergistic effect in reducing particle size. The nanoparticles with 0.80% (m/m) EGCG had the smallest particle size and the largest absolute value of zeta potential. After addition of EGCG, nanoparticles changed from a crystalline to an amorphous state, and its fluorescence intensity was quenched in a EGCG concentration-dependent manner. Compared with the SPA stabilized emulsion, the emulsifying activity, emulsion stability and oxidation stability of the emulsion stabilized with the composition nanoparticles were improved.

Crude polyphenols were extracted from white currant fruit from the small berry resource garden in Northeast Agricultural University and purified by solid phase extraction (SPE) into polysaccharide, anthocyanin and non-anthocyanin fractions. The chemical composition as well as the contents of total phenols and total anthocyanins in each fraction was determined. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging capacity, and ferric ion reducing antioxidant power (FRAP) were used to evaluate the antioxidant capacity of each fraction. The results showed that white currant fruit contained 78 non-anthocyanin polyphenols and only one anthocyanin polyphenol, corninin-3-glucoside, which can be used as a potential raw material for anthocyanin extraction. The contents of total phenols and total anthocyanins in the crude extract from white currant fruit were (34.93 ± 0.47) and (2.99 ± 0.98) mg/g, respectively. It had strong antioxidant capacity.

In this study, the contents of total phenols and total anthocyanins in blue honeysuckle fruit from six regions (Jiagedaqi, Xinlin, Hongwei, Amur, Tuqiang and Tahe) of the Greater Khingan Mountains were determined and compared, the antioxidant capacity of phenols from blue honeysuckle fruit was comprehensively analyzed using three different methods, and the hypoglycemic activity was evaluated by measuring its half maximal inhibitory concentration (IC₅₀) against α-amylase and α-glucosidase. The crude extract rich in polyphenols were separated and purified, and the resulting fractions were analyzed qualitatively and quantitatively. The results showed that the contents of total phenols and total anthocyanins in blue honeysuckle fruit from these six regions differed significantl, but the compositions were basically the same and all phenolic extracts had high antioxidant capacity. They had inhibitory activity against α-amylase and α-glucosidase, indicating the potential of blue honeysuckle fruit from these six regions for development and utilization.