Study On The Relationship Between Cell Wall Integrity Of Black Bean And The Physicochemical Properties And Starch Digestibility Of Cookies

In this study,black soybeans were used as raw materials,and black soybean powders of different particle sizes were obtained by a pulverizer.The integrity of the cell wall was evaluated by particle size analysis,optical microscope,electrical conductivity(CE)and iodine blue value(BVI),and X-rays Diffractometer(XRD),Fourier Transform Infrared Spectroscopy(FT-IR),Differential Scanning Calorimeter(DSC)and other measurement methods,to study the effect of cell wall integrity on starch structure,thermodynamic properties and functional properties;The black soybean powder was processed and its cell wall integrity was evaluated to further study the effect of cell wall integrity on starch structure and thermodynamic properties.At the same time,the cooked black soybean powder was mixed with wheat flour in equal proportions to analyze the functional characteristics of the cooked black soybean powder on the mixed powder.The effect of viscosity characteristics(RVA).Establish the correlation between the integrity of the cell wall and the physical and chemical quality and digestion characteristics of cookies.The main results are as follows:1.As the particle size of black soybean powder decreases,the specific surface area increases,and the average surface diameter and volume average diameter decrease.The dissolved starch,protein and ions increase accordingly,and the morphology and dense packing structure of large particle aggregates gradually weaken.It is a small particle aggregate,rich in more broken cells,showing greater conductivity and iodine blue value.The coarse fraction black soybean flour is rich in more intact cells,and the cell wall and specific surface area have the effect of limiting water absorption,oil absorption,swelling,dissolution and gelatinization of internal substances.Therefore,the coarse fraction black soybean powder has greater crystallinity,smaller water holding capacity,oil holding capacity,swelling power and solubility,and larger initial,peak,end gelatinization temperature and enthalpy change value.2.The cell wall integrity,crystalline structure and thermodynamic properties of cooked black soybean powder found that the cells are elliptical or elongated,the outline of a single cell is clearly visible,and the dense structure is gradually lost from coarse to very fine fractions,and starch in the cells is gelatinized to a certain extent.The number of rich intact cells gradually decreases,the dissolved starch,protein and ions increase,and the conductivity value and iodine blue value increase accordingly.Due to the changes in the cell wall pores caused by the cooking process,the electrical conductivity and iodine blue value of cooked black soybean powder are overall greater than those of raw black soybean powder;the cell wall barrier inhibits the gelatinization of the internal starch,causing the starch of the coarse-fraction cooked black soybean powder to show greater Crystallinity,but DSC does not detect gelatinization peak.3.The functional characteristics and viscosity characteristics of the mixed powder found that as the particle size decreases,the water holding capacity,oil holding capacity,swelling power and solubility increase,all viscosity parameters increase,and the gelatinization temperature decreases.It shows that adding cooked black soybean powder changes the functional properties and viscosity properties of the mixed powder,while the cell wall limits the water absorption and secondary gelatinization of the internal starch,and hinders the swelling of wheat flour.Therefore,the gelatinization temperature decreases from high to low.Analysis of the physical and chemical quality and digestive characteristics of biscuits found that crude and intermediate biscuits are easily liked and accepted by consumers.Coarse fraction biscuits are rich in intact cells,and dissolve less starch and protein.The Maillard reaction that occurs is conducive to changing the color,the browning index is the smallest,and the brightness is whiter.The hardness and breaking force are affected by the particle size and protein content,and the coarse fraction has a smaller hardness.The greater the water holding capacity of the biscuits,the lower the baking loss rate.The extension coefficients of coarse and intermediate fractions are lower than those of the control group,while the extension coefficients of the fine and very fine fractions are higher than those of the control group.Regarding the digestive properties of starch,biscuits rich in intact cells have lower digestibility,lower RDS content,higher RS content,and lower predicted glycemic index,even when compared to biscuits rich in broken cells.This result indicates that cell wall integrity can effectively reduce starch hydrolysis in complex matrix foods.In addition,the specific surface area,functional properties and crystallinity will also affect starch hydrolysis.Based on the above results,it can be seen that the biscuits prepared by adding the coarse and intermediate mixed powder have better physical and chemical quality,closer to the control group,and show higher nutritional value.