The Application Of Soybean Soluble Polysaccharide In Acidified Milk Beverage

Soybean soluble polysaccharide (SSPS) is extracted from soybeanby-product--Okara. It has a pectin-like structure. SPSS could be used to stabilizecasein at its isoelectric point and to prevent the aggregation and precipitation ofacidified milk beverage. Under the acidic conditions, SSPS is adsorbed onto thesurface of casein micelles by electrostatic attraction and could stabilize casein by asteric stabilizing effect of neutral sugar side chains. SSPS has a low viscosity, whichis suitable for adding to a refreshing acidified milk beverage as stabilizer.The effect of processing conditions to the stability of acidified milk beveragewhose stabilizer is SSPS was studied.Two different kinds of acidic beverage,including the direct acidified milk and fermentative milk were studied.The precipitation quantity,the stability coefficient and the particle sizedistribution of acidic beverage were determined as indexs of stability. The effect ofdirect acidified milk beverage processing conditions to the stability of acidic beveragewhose stabilizer is SSPS was researched.The optimum process parameters of thedirect acidified milk beverage (protein content1.5%) for SSPS as stabilizer was:acidification temperature5℃, acidification stirring rate1000r/min, homogeneouspressure30MPa, concentration of SSPS0.5%.The effect of concentration of SSPS to the stability of direct acidified milkbeverage was studied. SSPS as a stabilizer was added into the different type of thedirect acidified milk beverage under the optimum processing condition. The effect ofSPSS quantity on the stability of those different acidified milk was studied. Theconcentration of SSPS decreased with the rise of fat content, When there didn’t existfat separation, the fat is beneficial for stability. The concentration of SSPS increasedwith the rise of protein content, but it didn’t have a good stability when added to highprotein content. SSPS just suitble for low protein content refreshing acidic beverage.Acidified soy protein milk beverage had a high precipitation quantity. SSPS didn’t fitfor acidic beverage which had pure soybean protein or high adding amount ofsoybean protein as stabilizerThe precipitation quantity and the particle size distribution of acidic beveragewere determined as indexs of stability. The effect of fermentative milk beverageprocessing conditions to the stability of acidic beverage whose stabilizer is SSPS wasreasearched. The effect of fermentative process to the casein gel structure by measurethe rheology property was studied. The relation of stability of acidic beverage to therheology property of solidify yoghurt was found. The optimum process parameters of the fermentative milk beverage (protein content1.0%) for SSPS as stabilizer was:fermentative solids concent21%, fermentative temperature35℃, fermentativebacteria proportion S:L=2:1, fermentative time7h, homogeneous pressure40MPa,concentration of SSPS0.5%. The storage modulus G’ of solidify yoghurt is inproportion to the stability. The stability of SSPS is superior to pectin after theoptimum process conditions. The stability of SSPS is favorable during the storageperiod.