Extraction of polysaccharides from Gynura medica (GMPs) was optimized by response surface methodology (RSM). A central composition design including three parameters, namely extraction temperature (X₁), ratio of water to raw material (X₂) and extraction time (X₃), was used. The best conditions were extraction temperature of 91.7 °C, extraction time of 4.06 h and ratio of water to raw material of 29.1 mL/g. Under the optimized conditions, the yield of GMPs was 5.56%, which was similar to the predicted polysaccharides yield of 5.66%. A fraction named GMP-1 was obtained after isolation and purification by DEAE-52 and Sephadex G-100 gel chromatography, respectively. GMP-1, with a molecular weight of 401 kDa, mainly consisted of galacturonic acid (GalA), xylose (Xyl), glucose (Glu). Infrared spectroscopy was used to characterize the major functional groups of GMP-1 and the results indicated that it was an acidic polysaccharide. The antioxidant and α-glucosidase inhibitory activities of GMPs and GMP-1 were determined in vitro. The results indicated that GMPs and GMP-1 show potential for use in functional foods or medicines.

The decolorization process and adsorption mechanism of pigment molecules in alfalfa polysaccharides by S-8 resin were studied. Meanwhile, the physicochemical properties and antioxidant activity of alfalfa polysaccharides were analyzed.

In this study, the nutritional component and chemical constituents of Salicornia bigelovii Torr. were investigated, as well as their preservative effects on aquatic products. LC-MS of S. bigelovii extracts detected 34 compounds, 8 flavonoids were identified base on standard substance. Camellianin A and noreugenin were identified for the first time in S. bigelovii. Furthermore, the S. bigelovii could reduce the fish fillet loss-rate and inhibit the growth of microorganisms in aquatic products that impact cooking loss rate, pH, total volatile basic nitrogen (TVB-N), total viable count, and it also could reduce the damage of myofibrillar proteins texture changes. Finally, the S. bigelovii had a strong inhibitory effect on the dominant spoilage bacteria Pseudomonas in snakehead fish was demonstrated, and significantly prolong the preservation time of fish fillet till the 12 days. Overall, this study provides a basis for selection of suitable methods for the preservation and processing of aquatic products.

The Flammulina velutipes liquid strains were used as raw material, single factor and orthogonal test were conducted to optimize the semi‐continuous fermentation conditions. On this basis, the preservation time and the preservation quality of the semi‐continuous fermentation and batch fermentation of different temperatures were studied. The results showed that optimum semi‐continuous fermentation conditions were as follows: the feed batching time was fifth day, feeding amount was 60%, and the total fermentation time was 8 days; The optimum preservation temperature was 0–5°C, and the survival rate in this temperature range was 100%; The analysis of cellulase activity showed that the preservation quality of liquid strains produced by semi‐continuous fermentation was better than that by batch fermentation. These results provide a theoretical basis for the semi‐continuous fermentation and preservation of Flammulina velutipes liquid strains. Practical applications Compared with batch fermentation, the liquid strain of Flammulina velutipes could save more manpower and material resources by semicontinuous fermentation. In this study, we found that the quality of liquid strains of Flammulina velutipes prepared by semi‐continuous fermentation was better than batch fermentation. Therefore, the semi‐continuous fermentation of Flammulina velutipes liquid strains is more economical and affordable.