In this study, we used four drying methods (hot air, freezing, infrared, and radio frequency) to dry fresh jujube and its polysaccharide extracts by a two-step drying method, and the effects of the drying methods on the physical and chemical properties, structural properties, and antioxidant activity of jujube polysaccharides were studied. The results showed significant differences in the yield, drying time, monosaccharide content, molecular weight, apparent viscosity, thermal stability, and microstructure of the polysaccharides treated under the different drying methods. In contrast, no significant differences in the monosaccharide composition and functional groups of the polysaccharide samples obtained from the different drying methods were observed. Among all the tested methods, the freeze-drying extraction rate was the highest, reaching 4.52 ± 0.19%, while its drying time was the longest. Although the extraction rate of radio frequency drying was only 3.55 ± 0.21%, the drying time was the shortest, compared with hot air drying, the drying time was reduced by 76.67–83.29%, and the obtained polysaccharides exerted good antioxidant activity. Therefore, radio frequency drying is a potential polysaccharide extraction and drying technique, and this study can provide a theoretical basis for its industrial production.
Gas-containing conditioning technology (GCT) employs mild sterilization methods to preserve the original qualities and nutrients of foods and is particularly suitable for processing various cooked foods or food ingredients. In this study, five kinds of dishes from daily life were processed with GCT. Thermal penetration detection technology was utilized to monitor the internal temperature of food and ambient temperature in real-time, and the optimal scheduled processes of each food were summarized. Additionally, foods were processed after GCT, and the total number of bacteria (<102 cfu/g) and coliform colonies (<50 MPN/100 g) were significantly reduced. Moreover, to detect the preservation effect of GCT, the processed foods were stored at 37 °C for 14 days, and the total number of colonies remained low (<10 cfu/g). These results revealed the multistage mild sterilization process, confirmed the excellent sterilization and preservation effects of GCT, and provided important experimental data for further applications of GCT in special environment foods.
In order to verify the effect of the new fully biodegradable external dressing on the repair of diabetes skin wounds and the promotion of wound healing, this study applied sodium alginate hydrogel dressing products which are supplemented with phage and conotoxin analgesic peptides to the skin lesions of diabetes mice, and comprehensively used the quantitative measurement of serological indicators, Image J Tissue section and other techniques to evaluate the effect of the new hydrogel dressing on the repair of diabetes wounds and the promotion of wound healing. The behavioral observation and analysis of mice did not show obvious regularity and difference. According to the results of serum cytokine analysis, functional hydrogel dressings can promote cell regeneration and wound healing in mice. Image J software analysis showed that the healing results of the experimental group were better than those of the negative control group, and the percentage of collagen fiber content showed an upward trend. Through comprehensive evaluation, it can be observed that the new fully biodegradable external dressing has obvious positive effects on wound healing, collagen fiber reconstruction and wound infection prevention of diabetes. The new biodegradable dressing not only promotes wound healing but also solves environmental pollution problems. It meets the sustainable development needs of society and has broad application prospects.