Comparative Study On The Structure And In Vitro Function Of Four Kinds Of Dietary Fiber

As a good source of dietary fiber,whole grain wheat is favored by more people pursuing a healthy diet because of its higher content of dietary fiber,vitamins and minerals and stronger physiological activity compared with refined wheat.A growing body of research suggests that increasing dietary fiber in the diet can have beneficial effects on humans and experimental animals.These beneficial effects include the prevention or mitigation of diseases such as cardiovascular disease,diabete and colon cancer.This study selects the wheat,triticale,barley and quinoa four whole wheat as raw material to extract dietary fiber,the structure of the analysis of wheat and barley dietary fiber and structure-activity relationship between physical and chemical properties,physiological function,and compare four kinds of wheat and barley physical and chemical and physiological function of dietary fiber,through the comparison analysis of differences between reason,provides consumers with a more scientific and rational consumption of corn dietary fiber.Black wheat,wheat and quinoa SDF mainly by glucose,arabinose and xylose composition,highland barley SDF mainly for glucose monosaccharide;IDF's main monosaccharides are xylose,arabinose and glucose,containing a small amount of galactose and mannose.Ftir analysis results showed that SDF and IDF of wheat from different sources showed typical structure of polysaccharide compounds(for example,the absorption peak around 2930cm-1 was C-H contraction vibration),in which black wheat showed high strength in SDF peak and strong functional group activity.The apparent structure of dietary fiber extracted from different wheat was analyzed by SEM.It can be seen from the observation that SDF has loose structure and low degree of polymerization,and is more prone to form a network structure with water molecules,glucose and fat,etc.The surface of IDF presents irregular folds and a large number of cracks and pores,which are closely related to their physical and chemical properties.The order of SDF particle size was quinoa > black wheat > wheat > highland barley,and the order of IDF particle size was wheat > quinoa > highland barley > black wheat.The dissolution rate of black wheat SDF was 81.23%,which was significantly higher than the other three SDF.Black wheat SDF was still the highest in viscosity measurement.Except quinoa,the content of combined polyphenols in IDF of other three kinds of wheat was significantly higher than that of free polyphenols.In the determination of physicochemical properties,the water-holding capacity of black wheat and highland barley IDF was significantly higher than that of the other two kinds of wheat,while the swelling capacity of quinoa IDF was significantly higher than that of the other three kinds of wheat.The monosaccharide composition,structural characteristics,group activity,particle size,solubility and viscosity of dietary fiber from different sources are different,and the structural characteristics of dietary fiber can affect its physicochemical properties.Dietary fiber from different sources has certain activities of lowering blood lipid,blood glucose and antioxidant,among which wheat SDF and IDF have the strongest adsorption capacity for cholesterol,while black wheat and highland barley dietary fiber have a higher adsorption capacity for fat(saturated and unsaturated).SDF of black wheat had the best ability to adsorb glucose and inhibit leude-amylase,while IDF had a significantly lower ability to adsorb glucose than SDF,and the inhibitory rates of wheat IDF on leude-amylase and leude-glucosidase were significantly higher than those of other wheat varieties.By measuring the scavenging rate of hydroxyl radical and DPPH radical,reducing power and FRAP value of four wheat SDF,the antioxidant capacity of black wheat SDF was compared.The antioxidant capacity of IDF was lower than that of SDF,and the antioxidant capacity of the residue of IDF was significantly lower than that of IDF after extracting and combining phenols,while the antioxidant capacity of the extracted conjugated phenols was significantly higher than that of IDF and residue,indicating that the antioxidant capacity of IDF was mainly derived from the polyphenols it combined with,and the hypoglycemic activity of IDF was also related to the polyphenols it combined.These functional properties are closely related to dietary fiber structure,physicochemical properties and conjugated polyphenols.