The Study Of The All-grape Juice On The Preparation Process Parameters And Formulation

First of all, this experiment the best process paramenters and the basic formula of theall-group juice was determined based on the viscosity, pH value, precipitation rate, stability,soluble solids content and sensory evaluation index. The basic formulas were: sugar wasadded9%, citric acid0.105%, and lactic acid0.095%. The optimum processing parameterswere:refiner two times；homogeneous twice，homogeneouspressure of the first time was20MPa, the second time was30MPa, homogenization temperature was60℃, and the optimalsterilizing parameter was121℃, one second. The soluble solids content of all-group juice wasmore than10%and pH value was3.03at this time.Secondly, texture properties of nine kinds of hydrophilic colloid were studied,ecperimental results show that: the springiness oder of2%hydrophilic colloid was: Xanthangum＞Agar＞Xanthan gum＞Konjac gum＞Guar gum＞CMC＞High ester pectin＞Low-fatpectin=PGA, The springiness of Gellan gum and Agar were the greatest，a jelly-like gel state;The hardness order of the hydrophilic colloids was: Agar＞Xanthan gum＞Guar gum＞Xanthan gum＞Konjac gum＞CMC＞PGA＞High ester and low-fat pectin; And thedeformation was: CMC＞Konjac gum＞Guar gum＞High ester pectin＞low-fat pectin=PGA＞Xanthan gum＞Gellan gum＞Agar.Moreover, selected monomer hydrophilic colloid of better stability of all-group juice andcompleted the orthogonal experiment based on the viscosity and precipitation rate indexalthough the single experiment to the hydrophilic gel and salts. The best compound stabilizerformula was: High ester pectin, Gellan gum, Xanthan gum, Guar gum and sodiumtripolyphosophate, their add volume ratio was:5:3:2:5:6, compound stabilizer was added to2.1%. At this time, the viscosity of product was25.1mPa·S, pH3.03, precipitation rate6.05%,soluble solids content≥10%, and stability98.16%, the all-group juice system was stability,taste tastily, proper viscosity and aroma.Finally, the stability mechanism of the stabilizer and homogeneous process parameter onall-group juice was studied preliminarily by the microscope observation with camera, laserparticle size analysis and rheological method. The results indicated that, increasinghomogenization pressure and frequency, improve the homogenization temperature wereconducive to particle size reduction and the system more stable of the all-group juice; whenthe system of the shear stress increased gradually, the viscosity of product decreased gradually; when the shear time increased gradually, the viscosity of product decreased gradually and theshear-thinning phenomenon of all-group juice was obvious.