Effects Of Different Cereal Fiber Raw Materials On Biscuit Quality And Digestive Characteristic

In this study,wheat bran,oat bran,and rice bran were used as grain fiber raw materials.The cellulose of wheat bran,oat bran,and rice bran was extracted by nitric acid-ethanol method.The structure of cellulose was characterized by FT-IR,SEM,XRD and TGA.Different proportions of wheat bran powder,oat bran powder,and rice bran powder were added to prepare mixed powder,and the effect on dough characteristics and gluten protein structure was explored.MRI,RVA and dynamic rheometer were used to study the influence of dough moisture migration,gelatinization and rheological properties;the addition of 15% wheat bran powder,oat bran powder,and rice bran powder to the mixed powder the influence of gluten protein composition,water migration,and secondary structure of gluten protein.Study the effects of different addition amounts of wheat bran powder,oat bran powder,and rice bran powder on the sensory and texture of biscuits.The digestion characteristics of biscuits prepared by mixing wheat bran powder,oat bran powder and rice bran powder at 15% were analyzed.The main conclusions are as follows:(1)Using nitric acid-ethanol method to extract cellulose from wheat bran,oat bran,and rice bran,the changes in the internal structure of the cellulose of the cereal fiber raw material were observed,and the characteristics of the three celluloses were compared.The conclusions are as follows: SEM observation show: cereal fiber raw materials,namely wheat bran flour,oat bran flour,and rice bran flour have a loose structure and a smooth surface with more lumpy materials,while the extracted cellulose has a compact structure,rough surface and reduced lumpy materials,among which rice bran Cellulose is in the form of layers of stacked particles.The molecular structure of the cellulose in the cereal fiber raw material did not change during the extraction process,which was consistent with the infrared spectrum of the cereal fiber raw material,and the three cellulose structures were similar and the types were the same.The three types of cellulose are cellulose type I,and the crystallinity is 52%,57%,55.4%,which are 14%,20%,and 23.4% higher than that of cereal fiber raw materials.Therefore,the nitric acid-ethanol method can be effectively extracted Cellulose maintains the structure of cellulose,increases the stability of cellulose,and improves the crystallinity of cellulose.(2)The wheat bran,oat bran,and rice bran are crushed and sieved,and added to the wheat flour at different substitution ratios to prepare a mixed powder.The following conclusions are drawn: the greater the proportion of cereal fiber raw materials,the higher the ash,protein,fat content,water and oil holding capacity of the mixed flour,and the lower the moisture,crude fat,and wet gluten content.The weakly bound water in the dough increased first and then decreased,and was lower than that of the blank group.When the addition amount was about 15%,the water holding capacity of the dough was the strongest.With the increase in the content of cereal fiber raw materials,the storage modulus G’ value and loss modulus G " value of the dough gradually increase,and the storage modulus G’ value is always greater than the loss modulus G" value,the loss angle tangent value the tanδ first decreases and then increases,that is,the cereal fiber raw materials will increase the viscoelasticity of the dough and weaken the fluidity of the dough.The analysis of RVA characteristics shows that with the increase of cereal fiber raw materials,the peak viscosity,minimum viscosity,and end viscosity of the mixed flour all show a significant downward trend,indicating that the addition of cereal fiber raw materials leads to a decrease in the content of amylopectin in wheat flour;wheat bran The attenuation value of the hull group and the rice bran group decreased significantly,while the oat bran group showed a trend of first increasing and then decreasing;the dough retrogradation value of the wheat bran group decreased significantly,which may be related to the high cellulose content in wheat bran.(3)Exploring the influence of the addition of different grain fiber raw materials on the water distribution,gluten composition and secondary structure of gluten protein shows that: in the gluten protein added with grain fiber raw materials,water is more closely bound to protein or other macromolecules.The water holding capacity of gluten is enhanced.Among them,there are a large number of hydrophilic groups in the wheat bran,so that the water holding capacity of the wheat bran dietary fiber is greater than that of the rice bran and oat dietary fiber,so the water holding capacity of the gluten protein added with the wheat bran is increased.The addition of cereal fiber raw materials has little effect on the strong bound water in the gluten protein,but has a greater effect on the weakly bound water,and increases the content of weakly bound water.The content of glutenin and free sulfhydryl groups in gluten protein increased significantly,while the content of gliadin and disulfide bonds decreased significantly.The secondary structure of gluten protein is mainly α-helix and β-sheet.The content ofβ-sheet structure in gluten with wheat bran and oat bran is significantly increased,and the content of β-turn,α-helix and random curls Significant decline,while the secondary structure of rice bran gluten protein is not significantly different from wheat flour gluten protein.(4)Different addition amounts of wheat bran flour,oat bran flour,and rice bran flour are added to wheat flour to prepare biscuits.Studies have shown that with the increase in the amount of addition,the sensory score of biscuits increases first and then decreases.And when the addition amount of cereal fiber raw materials is 15%,the sensory scores of the three kinds of biscuits are the best;the hardness and chewiness of different biscuits first increase and then decrease with the increase of the addition amount,while the elasticity and adhesiveness of the biscuits gradually Decrease;at this time,the L*value and a* value of the biscuits are significantly reduced.Based on the abovementioned sensory,color and texture evaluation,the optimum addition amount of cereal fiber raw materials was determined.Exploring the effect of 15% addition of wheat bran powder,oat bran powder,and rice bran powder on the digestibility of biscuit starch and blood glucose index.It was found that the hydrolysis rate of biscuit decreased,and the content of SDS and RS increased,indicating the addition of grain fiber raw materials.Increase the content of slow-digested starch.The GI value of biscuits decreases with the addition of cereal fiber raw materials,and the lowest can reach 62.77.The effect of adding wheat bran and rice bran is particularly obvious.