Effects Of Germinated Brown Rice Flour And Improver On Dough Characteristics,Steamed Bread Quality And In Vitro Digestion

Germinated brown rice and its products are widely recognized by the public and the scientific community.They contain high levels of vitamins,proteins,minerals,cellulose,and ?-aminobutyric(GABA)and other biologically active substances.Postprandial blood glucose balance and other physiological functions.Studies have shown that the addition of sprouted brown rice flour to the traditional staple food can significantly improve the nutritional value and functional quality of the product.However,the germinated brown rice flour without have the viscoelastic properties of gluten protein,and the dough is not easy to form,resulting in a decline in the quality of the staple food product of germinated brown rice with a high ratio.Adding suitable modifiers to its staple food products can solve this problem well.In this paper,brown rice is used as the raw material to determine the optimal germination process of brown rice.The germinated brown rice flour and wheat flour are mixed in different proportions to make mixed flour dough and Chinese steamed bread(CSB).The effects of the amount of germinated brown rice flour and the types of improvers on the dough's rheological properties,alveograph characteristics,damaged starch content and CSB quality were explored.The aroma and taste of germinated brown rice-wheat CSB were revealed by electronic nose combined with GC/MS.Finally,through the in vitro simulated digestion method,the effect of in vitro digestion of germinated brown rice-wheat CSB starch was determined,which provided a theoretical basis for the development of germinated brown rice staple food products.The results are as follows:(1)Optimize the germination process of brown rice by single factor combined with orthogonal test.The optimal germination process of brown rice is as follows: the soaking solution is 3 mmol/L calcium chloride,the soaking time is 11 h,the soaking temperature is 30 ?,the germination time is 30 h,and the germination temperature is 28 ?.Under this condition,the germinated brown rice has high GABA content,good germination rate,bright and warm color,and suitable moisture content.(2)Study the effect of different proportions(0%,30%,40%,50%,60%,70%)of the amount of germinated brown rice flour added on the characteristics of dough and the quality of CSB.The results showed that with the increase of the proportion of germinated brown rice powder,the water absorption rate,formation time,and protein weakening degree of the mixed powder increased significantly.The stabilization time,starch gelatinization rate decreased.The tenacity and resistance to deformation(P)and the ratio of dough toughness to ductility(P/L)of the mixed dough increased significantly,while the extensibility of dough(L)and deformation energy(W)decreased significantly.The content of ethanol,2-pentyl furan,benzaldehyde,2-octanone flavor substances increased significantly,and SB rice has a strong fragrance.When the proportion of germinated brown rice exceeds 50%,the specific volume,elasticity,and sensory scores of CSB decrease significantly,and the hardness and chewability increase.The comprehensive selection of germinated brown rice flour is up to 50%.(3)The effect of improver on the quality of germinated brown rice-wheat dough and the characteristics of CSB.Taking the substitution ratio of 50% germinated brown rice flour as an example,the effects of hydroxypropyl methylcellulose(HPMC),xanthan gum(XG)and glucose oxidase(GOX)on dough properties and SB quality were explored.The results show that the binding ability of the improver to water is: HPMC>XG>GOX,and the effect on dough performance: XG>GOX>HPMC.HPMC significantly reduces the peak gelatinization viscosity,gelatinization stability,starch retrogradation performance,and increases the protein weakening rate.XG and GOX increase the dough's high temperature resistance and mechanical stirring ability.3%,4% HPMC,XG significantly increase P,L,W and damaged starch content of flour.The added XG SB have richer volatile flavor components,which are expressed as rich rice fragrance and sweetness.Combined with the influence of modifiers on dough properties and SB quality,when 0.3% XG is added,the dough performance is better,the aging rate is reduced,the specific volume is 2.53 mL/g,the hardness is low,and the sensory acceptance is the highest.(4)The in vitro digestion test of germinated brown rice CSB showed that the content of resistant starch(RS)gradually increased with the increase of the amount of germinated brown rice flour added,and the content of rapidly digested starch(RDS)and slow digested starch(SDS)gradually decreased.The in vitro starch digestion rate was also significantly lower than that of wheat CSB.Adding germinated brown rice flour to the main food CSB can improve the diet structure of diabetes patients.The digestible starch(DS)content of HPMC and XG CSB decreased significantly,the RS content increased,and the starch digestion rate decreased.The effect was HPMC>XG,while GOX showed the opposite trend.Adding 3% HPMC has the best effect on improving blood sugar after CSB.The in vitro digestion test of germinated brown rice CSB showed that with the increase of the amount of germinated brown rice flour,the resistant starch content(RS)gradually increased,and the contents of rapid digestion starch(RDS)and slow digestion starch(SDS)gradually decreased.In vitro starch digestion rate is also significantly lower than wheat CSB.Adding germinated brown rice flour to the main food CSB helps to stabilize the body's blood sugar balance after meals.The digestible starch(DS)content of HPMC and XG steamed CSB decreased significantly,the RS content increased,the starch digestion rate decreased,the effect was HPMC>XG,and the addition of GOX showed the opposite trend.Adding 3% HPMC has the best effect on improving blood sugar after CSB.