《食品工业科技》F5000论文展播：山楂多糖提取工艺优化及其降血糖、降血脂活性（2022年）

Objectives:Crataegus pinnatifida Bunge is a fruit that can be used for both medicine and food in China. It has a wide planting area and considerable yield, and is commonly used to lower blood sugar and blood lipids. According to reports, hawthorn is rich in chemical components such as polysaccharides, polyphenols, organic acids, triterpenes, sterols, carotenoids, amino acids, and trace elements. Among them, polysaccharides are an important class of bioactive substances in hawthorn. This article optimized the microwave assisted extraction process of hawthorn polysaccharides and studied their hypoglycemic and lipid-lowering activities, in order to lay a foundation for the development and utilization of hawthorn resources and the development of hawthorn source health products.

Methods:Hawthorn powder was extracted using petroleum riddle at a ratio of 1:2 (g/mL) to remove fat soluble substances, with 15 mins each time, repeated three times, and filtered and dried. After thoroughly mixing a certain mass of hawthorn powder and deionized water at a certain solid-liquid ratio (g/mL), microwave assisted extraction was carried out. The extract was centrifuged at 4 ℃ at 4500 r/min for 10 mins, and the supernatant was concentrated, dried, and redissolved in a certain amount of deionized water. Four times the volume was added to precipitate with anhydrous ethanol for 12 hours. Centrifuge at 4500 r/min for 20 mins, precipitate and dry to obtain hawthorn polysaccharide extract. Dissolve the hawthorn polysaccharide extract in deionized water and remove the pigment using activated carbon adsorption method with a liquid-solid ratio of 3:1 (mL/g). Take the sample solution after depigmentation and shake it in a constant temperature water bath shaker (200 r/min) for 20~30 mins with a volume ratio of 3:1 between the sample solution and Sevag reagent. Centrifuge at 400 r/min for 20 mins. Take a small amount of supernatant to determine the quality of the protein. Repeat the treatment for 5 times, remove the protein, and freeze dry to obtain hawthorn crude polysaccharide. Based on investigating the effects of solid-liquid ratio (1:20, 1:25, 1:30, 1:35, 1:40 g/mL), extraction temperature (40, 50, 60, 70, 80 ℃), microwave power (300, 400, 500, 600, 700 W), and extraction time (3, 6, 9, 12, 15 mins) on the extraction amount of hawthorn polysaccharides, Box Behnken response surface methodology was used to optimize the extraction process. The inhibitory activities of α-glucosidase and pancreatic lipase were measured, and the DPPH· free radical scavenging effect was measured and its clearance rate was calculated.

Results:The optimal conditions for extracting hawthorn polysaccharides were power 493.81 W, extraction time 7.03 mins, and extraction temperature 63.49 ℃. The maximum predicted extraction amount of hawthorn polysaccharide extract under the optimal extraction conditions is 148.28 mg/g. Considering the actual situation, the optimal process conditions for final correction were determined to be power 500 W, extraction time 7 mins, and extraction temperature 63 ℃. Under the corrected conditions, the validation test showed that the extraction amount of hawthorn polysaccharide extract was 147.10±0.32 mg/g. The hawthorn polysaccharide extract obtained through the above optimal conditions had a polysaccharide content of 39.32%±0.80%.Within the experimental range, with the increase of the mass concentration of hawthorn crude polysaccharide, the inhibition rate of α-glucosidase and pancreatic lipase showed a gradual upward trend. The IC50 value of hawthorn crude polysaccharide on the inhibition rate of α-glucosidase was determined to be 99.22±0.89 μg/mL. The IC₅₀ value of pancreatic lipase inhibition rate was 22.50±0.79 mg/mL, indicating that hawthorn crude polysaccharide had a good lipid-lowering effect. Within the experimental range, with the increase of the mass concentration of hawthorn crude polysaccharide, the DPPH· clearance rate showed an upward trend. The IC₅₀ value of hawthorn crude polysaccharide on DPPH· clearance rate was determined to be 185.80 ± 0.64 μg/mL indicated that hawthorn crude polysaccharides have good antioxidant effects.

Conclusion:The optimal extraction process conditions for hawthorn polysaccharides are extraction temperature of 63 ℃, microwave power of 500 W, extraction time of 7 mins. Under these conditions, the extraction amount of hawthorn polysaccharides was 147.10±0.32 mg/g. The IC₅₀ values of crude hawthorn polysaccharides on the inhibition rate of α-glucosidase, pancreatic lipase, and DPPH· clearance rate were 99.22±0.89 μg/mL, 22.50±0.79 mg/mL, 185.80±0.64 μg/mL, indicating that hawthorn crude polysaccharides had certain hypoglycemic and lipid-lowering effects, providing a theoretical basis for further processing of hawthorn products.