The Study On The Yam Flour Properties And It’s Application On Biscuit Processing

Yam is one of the traditional Chinese medicine of“medicine food homology”.It’s also one of the important staple food in tropical countries.It has rich nutritional and medicinal value,contain a variety of bioactive components.But the application degree of yam flour was low,most of yam flour as functional component addition in relative product researches.To rich scope of yam flour application in the food industry,this study researched physicochemical properties,farinograph parameters and Alveograph parameters of yam flour.To explore the application of yam flour in biscuits,this study researched biscuit formula and technology optimization,and also took quality evaluation for yam biscuit.The main research contents were as follows:（1）Yam flour properties research.Chemical characteristics indexes results showed that all the varieties yam flour contain starch 60⁶5%,total sugar 70⁸0%,ash 3%,fat 0.5%,protein 12¹3%,moisture 2⁴%.The results of microstructure feature and starch particle diameter showed that the starch granule in yam storage root was 10⁴0μm in diameter,and it had a unimodal number distribution,the yam flour starch granule of Gui Yam No.4,Gui Yam No.6 and Gui Yam No.7.In addition,Gui Yam No.7 flour had better whiteness,litter flours granularity,better water absorption capacity,the best oil holding capacity,lower water separation ratio and the shortest dispersion time.Through farinograph properties researching,based on Gui Yam No.7,with the increase of yam flour proportion,the formation time of dough gradually grow;the changed trend of softness first increase,then decline,rise again;stabilization period and farinogragh quality number first decline,and increase,and then decline.Alveograph properties data showed,with the increase of yam flour proportion,P-value first increase,then decline,got the maximizing 86.61mmH₂O when yam-wheat flour proportion is 6:4;L-value was divided in two stages,79⁸7mm and 34⁴0mm.（2）Through single factor experiment and orthogonal test,it obtained yam biscuit basic formula:proportion of yam-wheat mixed power 1:4,water 18%,sugar 33%,butter 30%,milk powder 3%,baking powder 1%.And yam biscuit technology optimization:dough mixing time 4min,baking time 4min,surface layer temperature 220℃,bottom layer temperature170℃.Through quality assessment of the yam biscuit,it obtained water absorption 51.20%,alkalinity 0.22%,acid value 2.66mg/g,peroxide value 0.19g/100g,hardness 973.3g.