Study On The Effect Of Germination Degree On Macro Components Of Pea And Processing Characteristics Of Pea Whole Flours

Pea is not only rich in nutrients,but also contains a variety of bioactive substances which are potentially beneficial to human health.Pea has the functions of antioxidation,lowering blood pressure,improving liver and kidney function,inhibiting tumor,etc.However,there are some antinutritional substances in pea,such as protease inhibitor,phytic acid and lectin,which affect digestion and absorption;peas themselves contain heavier bean flavor,which limits the wide application of peas in food processing.Therefore,improving the nutritional value of pea foods,reducing or removing the fishy smell of pea to improve the sensory experience of products is an important issue in pea food processing.In this paper,peas were used as raw materials.The peas germinated at 25? until the bud length was less than 1 cm,the bud length was 1~2 cm,the bud length was 2~4 cm,and the bud length was 4~5 cm.Then the peas were dried to constant weight by blast drying.The effects of germination degree on the nutritional components(starch,dietary fiber,protein,total phenol content)of pea and the processing characteristics(hydration characteristics,gelatinization properties,gel texture properties,rheological properties,thermodynamic properties and farinograph property)of pea whole flours were studied,and the influencing mechanism was discussed.Meanwhile,the dough characteristics and bread quality of the pea whole flours were analyzed.The main conclusions are as follows:(1)With the increase of germination degree,the content of starch and lipid in pea decreased gradually,the content of protein and soluble dietary fiber(SDF)increased gradually,the content of total dietary fiber(TDF)increased first and then decreased.There were no significant changes in the particle morphology,crystal structure and functional group structure of pea starch before and after germination.The pea starch is round or elliptical,most of the surface is smooth,a few of the surface has dents;with the increase of germination degree,some dents and pits appear on the surface of the starch granules,and the starch granules gradually decrease,and the content of damaged starch gradually increase.The crystalline form of pea starch is C type,and the crystallinity of pea starch after germination decreases,and gradually decreases with the increase of germination degree.After germination,pea starch had no new functional groups,but its double helix structure decreased.With the increase of germination degree,the content of rapid digestion starch(RDS)of germinated pea increased significantly,the content of resistant starch(RS)decreased significantly,the molecular weight of isolate protein gradually decreased,and the total phenol content increased.(2)Germination changed the hydration characteristics of pea whole flour,after germination,the water absorption and swelling capacity of the pea whole flours decreased,and the water solubility decreased and then increased.Short-term germination(bud length <2 cm)significantly increased the gelatinization viscosity of pea whole flours;long-term germination(bud length > 2 cm)reduces the gelatinization viscosity of the pea whole flours.Germination increased the onset temperature(To)and the peak temperature(Tp)of the pea whole flours,and decreased the enthalpy change(?H).Germination increased the hardness,adhesiveness and chewiness of pea whole flours,and the recovery was decreased.There was no significant difference in elasticity and cohesion.The gel strength of pea whole flours decreased as the germination degree increased.Through the study of rheological properties,it was found that the pea whole flours fluid with 5% mass fraction is a typical pseudoplastic fluid,which shows a solid like elastic behavior,and germination improves the viscoelasticity of pea whole flours.With the increase of the amount of pea flour,the water absorption,formation time and stability time of the pea-wheat mixed flours decreased,and the degree of weakening increased.When the addition amount of the pea whole flours is 5%,the farinograph property of the pea-wheat mixed flours is improved,but the germination degree of pea has a great influence on the quality of pea-wheat mixed flours.(3)Adding 5% of the pea whole flours to the wheat flour could significantly change the moisture distribution of the free water,the hard flowing water and the combined water of the dough,increase the stickiness of the dough,reduce G',G''and Tan?,decrease the viscoelasticity of dough,and enhance the gas production and holding capacity of dough.Compared with the raw pea whole flour,the proportion of bound water in the dough with 5% of the germinated pea whole flours increased,the proportion of the hard flowing water decreased,the viscosity of the dough decreased,and the gas production and gas holding capacity of the dough decreased,the G',G'' and Tan? increased,the viscoelasticity of the dough is improved,and the bread aging speed was slow(in the storage period of 1-7 days,the hardness change range was small).After adding the pea whole flours,the color and smell of the bread changed.After adding pea whole flours,the color and smell of bread changed.Adding germinated pea whole flours improved the dough processing characteristics and bread quality,and effectively reduce or remove the beany smell of bread.This study provided theoretical basis and experimental basis for promoting the processing and application of beans,increasing the intake of dietary fiber,and developing high-nutrition functional foods.