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Native potato starch (NPS) with tea polyphenols (TPs) was treated in a planetary ball mill, and the effects of co-grinding on properties and digestibility of starch were studied. The X-ray diffraction (XRD) results showed that the crystal structure of starch granules was destroyed after 7 h of ball grinding, and their crystallinity degree reduced from 38.1% to 8.3%. The scanning electron microscopy (SEM) analyses indicated that the damaged starch granules and TPs displayed agglomerates after 7 h of milling. The Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) results demonstrated the existence of an interaction between starch chains and TPs, which improved the thermal stability and gelatinization temperatures of starch. The ball-milled starches with different amount of TPs showed significant variability to in vitro digestion (the contents of slowly digestible starch and resistant starch). Therefore, the produced ball-milled mixtures may be a desired dietary product for postprandial glycemic control.

Burns are a global public health problem and the treatment of burn wounds is a major medical and economic issue. White jade snails (Achatina fulica) are now widely distributed in Asia, and they have been used to treat burns in folk medicine of China. In this study, the glycoproteins from white jade snails were investigated and their effect on burn healing was evaluated by a mouse burn model. The results showed that the snail mucus was mainly composed of proteins and polysaccharides, and it had good adhesion. The main component of snail mucus was glycoprotein from the results of DEAE Sepharose FF ion exchange chromatography. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging effect of 1 mg/mL snail mucus reached 13.77%. The wound healing rate of the snail mucus group was higher than that of the control group (p 0.0001). Histopathological results showed that mice in the snail mucus group had a faster healing than that of the control group. The biochemical analysis was in agreement with the histopathological findings. These results suggested that glycoproteins from snail mucus showed effective wound healing activities in the skin of experimentally burned mice.

Dictyopteris divaricata is a kind of important brown algae with many biological activities. It has been receiving more and more attention, yet there are rarely studies done on its polysaccharides. In this study, the optimum extraction and biological activity of seaweed polysaccharides from Dictyopteris divaricata (DDSP) were investigated. Response surface methodology (RSM), based on a three-level, three-variable Box-Behnken design (BBD), was employed to obtain the best possible combinations for maximum polysaccharides yield. The optimum extraction conditions were as follows: liquid-solid ratio of 110 mL/g, extraction time of 6 h and extraction temperature of 100 °C. Under these conditions, the experimental yield was 3.05%, which was in close agreement with the predicted value of 3.15%. The average molecular weight of DDSP was 58.05 kDa. Gas chromatograph (GC) results showed that DDSP was composed of fucose, xylose, mannose, glucose and galactose with the corresponding molar ratio of 4.45:2.74:1.00:2.94:1.35. Biological activity showed that DDSP exhibited strong antioxidant activity in vitro and possessed the potential on stimulating immune response of RAW264.7 cells. So DDSP can be used as a natural ingredient in functional foods.

The polysaccharides of Ganoderma lucidum (GLP) extracted by the methods of ultrasound assisted extraction (UAE) and hot water extraction (HWE) were characterized and the antioxidant activities of GLPUAE and GLPHWE were compared. High performance gel permeation chromatography (HPGPC) showed that the average molecular weight of GLPUAE and GLPHWE were 465.65 kDa and 703.45 kDa, respectively. GLPUAE was composed of mannose, rhamnose, glucose, galactose and arabinose in the molar ratio of 2.58:1.25:11.17:2.5:1, while GLPHWE was composed of the same monosaccharide in the ratio of 3.11:1.11:19.44:2.33:1. GLPHWE showed a relatively higher antioxidant activity than GLPUAE by testing the reducing power, the scavenging ability on 1.1‑diphenyl‑2‑picryl‑hydrazyl (DPPH), hydroxyl radical and cellular protective effect on yeast cells from ultraviolet radiation (UV) damage. GLPUAE and GLPHWE were purified by chromatographic column of DEAE-52 cellulose. GLPUAE, GLPHWE and the purified components could be novel antioxidants for functional food.

In order to study the effect of metal ions on the enzymatic hydrolysis of hemp seed oil by Candida sp. 99-125, the spectroscopy, stability and hydrolytic activity of the biocatalyst were investigated in presence of Ca2+, Mg2+, Fe2+, Fe3+, Cu2+, Sn2+, Pb2+, Zn2+ and Ba2+ metal ions, respectively. The UV spectroscopy showed that all the metal ions enhanced the absorbance but the decrease of fluorescence intensity was observed. All the metal ions could improve the lipase thermal stability except Cu2+ and Ba2+. Hydrolysis of hemp seed oil proved that Ca2+, Fe3+, Pb2+ and Ba2+ could significantly improve the hydrolytic rate, and metal ions could influence lipase selectivity. The study revealed that metal ions could improve lipase stability, hydrolysis activity in the hydrolytic process of hemp seed oil by Candida sp. 99-125.

The characteristics and biological activities of a novel polysaccharide from Lepidium meyenii leaves (LMLP) were investigated. LMLP was purified using DEAE-52 cellulose chromatography followed by SephadexG-100 chromatography. The average molecule weight of LMLP was 58.43kDa and it was composed of galactose, arabinose, rhamnose, glucose and mannose with a relative molar ratio of 5.51:4.05:1.15:0.77:0.01. Antioxidant activity results showed that LMLP presented an EC50 of 3.72mg/mL in scavenging 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical, and it also had reducing power (OD700nm being 0.079 at 1mg/mL). Moreover, LMLP possessed the potential on stimulating immune response of RAW264.7 cells. It could promote proliferation, strengthen phagocytosis function, enhance the expression of CD80, and increase the secretion of nitric oxide (NO) in a dose-dependent manner. All of these results suggested that LMLP could be used as a natural ingredient for functional food.