Extraction,Properties And Functions Of Water-soluble Dietary Fiber From Cherry Wine Residue

Fresh cherry fruit is rich in nutrients,in addition to direct consumption,mainly used for the production of fruit juice and fruit wine.A large amount of waste will be generated in the production process of fruit juice and fruit wine,causing serious pollution and waste.Cherry wine residue accounts for about 20%of the fresh weight of cherries.It is mainly composed of skins and cores.It mainly contains nutrients such as protein and dietary fiber.The content of starch and fat is less.The total dietary fiber content can reach more than 70%of the dry weight.Overweight and obesity are worldwide public health problems,among which the World Health Organization survey shows that the number of obesity in the world has increased approximately twofold between 1980 and 2017,which has led to the definition of dietary fiber as the"seventh nutrient"of human beings,and its role in the prevention and treatment of overweight or obese patients has received increasing attention.Therefore,taking cherry wine residue as the research object of this experiment can not only solve the waste problem,but also provide a theoretical basis for the utilization of cherry wine residue dietary fiber.In this experiment,two methods were used to extract water-soluble dietary fiber from cherry wine residue,and the differences in the structural composition and physicochemical properties of water-soluble dietary fiber obtained by the two extraction methods were compared,and the effect of high-fat dietin duced obesity prevention in mice was investigated.The following results were obtained.(1)The enzymatic extraction of water-soluble dietary fiber(SDF)from cherry wine residue was carried out with the optimal extraction process of cellulase addition of 7%,enzymatic digestion for 1 h,temperature of 55?,p H 5.4,material-liquid ratio of 1:20 g/m L,and yield of 12.01±0.53%.The acid extraction of water-soluble dietary fiber from cherry wine residue was carried out with the optimum extraction conditions of a material-liquid ratio of1:60.8 g/m L,mass fraction 5.2%,time 75 min,extraction temperature 73?,and yield39.49±0.32%.(2)The surface of enzymatically extracted SDF was loose and porous.The absorption intensities and functional group types of the two SDFs at the corresponding wave numbers were slightly different,and both had absorption peaks typical of carbohydrates.XRD results showed that the extraction method did not change the crystal type of SDF,and the two SDFs coexisted in the crystalline and amorphous states.The monosaccharide composition of the two SDFs was the same,and the monosaccharide content of the enzymatically extracted SDF was 58.7%higher than that of the acid-extracted SDF.Physically,SDF extracted by enzymatic method had better water holding rate,oil holding rate,emulsification stability and solubility,while SDF extracted by acid method had better emulsification activity.Both SDFs had better cation exchange ability,among them,the acid-extracted SDF may contain more H~+for cation exchange.Both SDFs were pseudoplastic non-Newtonian fluids,and the apparent viscosity increases with increasing mass concentration and decreases with increasing shear rate.Both SDFs were strong for nitrite adsorption at p H 2 and cholesterol adsorption at p H 7,and the enzymatic-extracted SDF had stronger adsorption capacity.Both SDFs had antioxidant activity,and the enzymatic-extracted SDF had higher DPPH radical scavenging capacity,ABTS~+radical scavenging capacity,and total antioxidant capacity than the acid-extracted SDF.(3)Experiments on mice showed that SDF could significantly reduce body weight and food intake in mice induced by high-fat diet.It did not change the organ weight of mice,but could reduce the accumulation of fat.Two SDFs can effectively reduce total serum cholesterol,triglyceride,low density lipoprotein cholesterol and atherosclerotic index,and the enzymatically extracted SDFs could increase high density lipoprotein cholesterol.The results of oxidative stress tests showed that both SDFs reduced malondialdehyde levels and levels of glutathione,increased levels of superoxide dismutase,and reduced cellular oxidation levels.Liver and fat sections showed that SDF intake reduced hepatic lipid droplet aggregation,decreased the risk of hepatic steatosis,facilitated the reduction of adipocyte size and prevented adipose tissue lesions in obese mice.