Effect Of Germination On Characteristics Of Starch Isolated From Waxy Brown Rice And Its Application In Glutinous Dumplings

As a traditional glutinous rice food in China,tangyuan is deeply loved by people.Quick-frozen glutinous rice balls have many shortcomings,such as large adhesion,sticky teeth after re-cooking,difficulty in swallowing,etc.,which is especially not good for the elderly and children to eat.During the processing of glutinous rice balls,due to the poor water retention and ductility of the glutinous rice balls themselves,the quick-frozen rice balls are prone to cracking,shape collapse,dedusting,cooking quality decline and other phenomena,which seriously affect the quality of the quick-frozen rice balls.After Germination,waxy brown rice is expected to improve the starch characteristics of rough glutinous rice,so as to provide new ideas for improving the product quality of tang yuan.In addition,the germinated waxy rice flour may also improve the variety and content of nutrients,making nutrients of the dumplings become more balanced.Therefore,the purpose of this study is to adopt the germination treatment of waxy brown rice,and systematically study the changes of the nutritional composition,starch multi-scale structure and physicochemical properties of waxy brown rice at different germination stages,and the application of germinated waxy rice powder in quick-frozen glutinous rice dumplings.The main conclusions are as follows:?1?The effects of different germination conditions?time,temperature and humidity?on the gelatinizing viscosity of starch in rough glutinous rice were studied.It was found that the effect of germination time on the gelatinizing viscosity of starch in rough glutinous rice was relatively stable,which could be used as the optimal process condition to regulate the characteristics of starch in rough glutinous rice.With the prolongation of germination time,the enrichment of nutrients such as thiamine-aminobutyric acid,ferulic acid and total phenol in waxy brown rice and the increase of?-amylase activity.Germination improves the nutritional value of waxy brown rice.?2?It was found that the molecular chain structure,crystalline structure,lamellar structure and granular structure of starch in waxy brown rice were changed after germination treatment.Among them,germination caused the side chains of amylopectin in glutinous rice to break,and the contents of B₁,B₂ and B₃ chains of amylopectin decreased,while the contents of A chain increased.The content of double helix structure decreased and the content of amorphous structure increased.The amorphous structure of starch increased and the ordering degree and relative crystallinity of starch granules decreased.The thickness of semi-crystalline layer of starch decreased and the thickness of amorphous layer increased.The surface of starch particles became rough and the regularity decreased,and pits and holes appeared,and the particle size decreased.?3?It was found that the germination treatment increased the swelling degree and solubility of the starch granules and enhanced the coagulation characteristics.The peak viscosity,final viscosity,retrogradation value and disintegration value in starch gelatinization were decreased.The consistency coefficient of starch paste decreased,the fluidity increased,and G'and G'decreased.Starch paste hardness,cohesion,viscosity and masticatory decreased.Starch T_o,T_P increased,T_C decreased,starch particles heat stability enhanced.?4?It was found that adding germinated brown rice flour could reduce the water loss rate and freezing crack rate of the dumpling,and improve the deterioration of the dumpling in the freezing process.However,the addition of germinated brown rice flour also reduced the transmittance of the soup during the cooking process and the stability of the dumplings during the cooking process.In addition,the addition of the right amount of germinated brown rice flour resulted in the decrease of hardness,adhesion,elasticity,cohesion and recovery in the gelatinous texture characteristics of the dumpling,which made it refreshing and non-sticky,and improved the edible quality of the dumpling to some extent.The addition of germinated brown rice flour in simulated in vitro digestion led to the increase of RDS and SDS content in tangyuan powder,and the decrease of RS,which made tang yuan easier to be digested.Sensory evaluation,the integrity of the germination of waxy rice flour add make dumplings,viscosity,taste and total sensory scores increased,but the excessive germination of waxy rice powder added to cause a decline in tang yuan the overall quality,tang yuan present rice smell is not obvious,color slants yellow,surface crack,eat no texture,the phenomenon such as low viscosity,has a bitter taste,sensory score decreased significantly,the serious influence the edible quality of sweet dumpling.