The Application Of Mixolab And RVA On The Detection Of Glutinous Rice Flour Quality

This paper studied on the correlation between the main continents ofglutinous rice flour, the characteristic values of Mixolab and RVA and thequality indexes of glutinous rice four including the water-holding ability,the freeze-thaw ability, the light transmittance of their tangyuan soup andthe sensory evaluation scores of tangyuan. Establish the mathematicalmodel of predicting these quality indexes through Mixolab and RVA. Theresults showed as follows:(1) The moisture content of glutinous rice flour has a verysignificant positive correlation with the color and the gloss of tangyuan.The starch content has a significant positive correlation with theadhesiveness, the tenacity, the gloss and the total score of tang yuan.(2)Both RVA and Mixolab cannot be used to predict thewater-holding of glutinous rice flour. C3-C4, the characteristic values ofMixolab, reflecting the deliquesce degree of glutinous rice flour gel, canbe used to predict the freeze thaw of glutinous rice flour separately, theless its value is, the worse the freeze thaw is. Using Mixolab and RVAtogether to predict the freeze-thaw can promote the accuracy degree to93.1%, but it need more parameters, including C1(the top torque after thedough is mixed uniformly), the stability time of the dough, C2(theminimum torque of the dough after its protein structure is destroyed bythe mixing force), T2(the starting temperature of the gelatinization ofglutinous rice flour), C4(the minimum torque after the glutinous riceflour gel is deliguesced), β (the gelatinization speed of gluninous riceflour), γ(the enzymolysis speed of amylase), C5-C4(the torque changeafter the glutinous rice flour is cooled), the setback and the pastingtemperature.(3)The minimum viscosity is a key parameter to predict the color, the gloss and the total score of tangyuan. The final viscosity can also predictthe gloss of tangyuan. The pasting temperature can predict the smell oftangyuan. The less their values are, the better the color, the gloss and thetotal score of tangyuan are, together with the peak time, the accuracydegree can be higher. C3-C2and C2of Mixolab can together pedict thegloss of tangyuan, the less the value of C2and the more the value ofC3-C2are, the better the gloss of tangyuan is. The model of setback, peaktime, pasting temperature and t1(the time before the dough becomeuniformly under mixing) together predict the smell of tangyuan canpromote the accuracy degree to86.9%. The model of minimum viscosity,setback, pasting temperature, T2and β together predict the color oftangyuan can promote the accuracy degree to72.9%. However, the predictmodel of the light transmittance of tangyuan soup is not significant, thatis, both Mixolab and RVA are not suitable to predict the lighttransmittance of tangyuan soup.