Research On The Preparation Process Of Juice-oat Beverage

Juice-oat beverage, mainly made up of oat and juice, is a kind of new healthy cerealbeverage with balanced nutrition, exquisite taste and full aroma, whose process contains roasting,grinding, boiling, mixing, high-pressure homogenizing, UHT sterilizing and hot filling.Firstly, the two methods, grinding and enzymolysis process were used and compared toprepare the oat plasm. Results showed that when the grinding method was used, solid extractionrate, protein extraction rate, beta-glucan content and raw material utilization ratio reached84%,51.29%,55.6mg/L,87.30%, respectively. As for the enzymolysis method, these values were79.84%,36.72%,103.48mg/L,81.48%, respectively. In consideration of test goal, grindingmethod was more effective and the optimized process technology was as follows: whole oat wassoaked in0.5%NaHCO3solution at oat/water ratio1:3(w/w), at20℃for about10hours; afterthat, oat was ground with95℃hot water for12minutes at oat/water ratio1:20(w/w).In addition, the results of organoleptic evaluation experiments showed that the best beverageformulation consisted of oat-milk(78%), apple juice(15%)and sugar(7%)with pH at5.1.Secondly, the influence of food additives on beverage’s stability and anti-retrogradationwas studied. The SR was used to evaluate thickener’s effect on stability. The ratio of CMC, PGAand xanthan gum was obtained by the simplex centroid design. The results showed that theadditive dosage of CMC, PGA and xanthan gum was0.107%,0.069%and0.098%; amount to0.274%(mass fraction). Then the retrogradation degree was used to choose the suitableanti-retrogradation agents. The result indicated that the most suitable anti-retrogradation agentsfor the beverage was the mixture of sugar ester-15(0.15%), DMG(0.05%) and compoundphosphate (0.03%)(mass fraction).Moreover, effects of homogenization pressure, temperature and times on the diameter ofparticles and stability were also investigated. The optimum homogenization condition was that thebeverage was homogenized2times at60MPa and60℃.Then, effects of high temperature sterilization, PEF sterilization, UHT sterilization threedifferent sterilizations on colour, pH, SR, particle size and rheological behaviour was studied. TheUHT sterilization technique has minimum influence on the product.Finally, the shelf life of the beverage was forecasted through accelerated shelf life testing.The aerobic plate count, centrifugation sedimentation rate, viscosity, diameter of particles, pH andsensory scores were all determined. The research indicated that correlation coefficient betweensensory scores and centrifugation sedimentation rate was the highest. Centrifugationsedimentation rate was used for the parameter to establish the prediction modelSS=-0.2719×{SR×exp[t×(k_bT)／h×exp-(140.6T+43661)/RT]}+5.9978. According to the model, the shelf life of the juice-oat beverage was about191days.