Research And Development Of Whole Soybean Milk And Instant Whole Soymilk Powder

Soybean milk is not only a kind of high-quality vegetable protein drink but also an intermediate product in the preparation of a variety of soybean products.At present,there are many problems in soybean milk industry,such as the quantity of dry soybean soaking wastewater and the quantity of okara.The fresh okara is easy to rot and difficult to preserve,and the drying cost is huge,which brings great pressure for processing to soybean products manufacturers.At the same time,okara contains a large amount of dietary fiber and protein.Filtering out okara could improve the texture and stability of soybean milk,however,its nutritional value reduces concomitantly.In this research,the production process of whole soybean milk was optimized,the storage quality of whole soybean milk was investigated,and different instant whole soybean powder formulations were compared.The preparation of whole soybean milk and instant whole soybean powder is expected to provide some reference for the development of whole soybean food.First of all,peeled soybeans were selected as raw materials without soaking,and pilot wet pretreatment equipment and industry-scale microfluidization were used to prepare liquid the whole soybean milk without any stabilizer or emulsifier added.The levels of orthogonal factors were determined by taking soluble protein content,stability index and sensory evaluation results as indicators.Through orthogonal test,the optimal process conditions for the pilot production of the whole soybean milk were determined:soluble solids content of 10%(soybean water ratio of about 1:8),industry-scale microfluidization treatment of 90 MPa,cooking at 95? for 5 min,adding 4%granulated sugar.The whole soybean milk with good stability and taste can be prepared by this process.On the basis of process optimization,the storage properties of the whole soybean milk were investigated at different storage temperatures(4?,28?,38?)for 90 days.The apparent stability,centrifugal precipitation rate,soluble solids content,pH,particle size,viscosity,color difference,total number of bacterial colonies and urease activity were determined.The experimental results showed that the whole soybean milk stored at 4? could maintain a good stability within 90 days,as the quality indexes of the samples were hardly changed,and the total number of bacterial colonies and urease activity were in line with the national standards for soybean milk products.The whole soybean milk stored at 28? for 90 days showed a small amount of fat floating without any precipitation and deterioration,so it is still qualified for normal consumption.For the sample at 38?,the total number of bacterial colonies exceeded the standard after 90 days storage,which lead a significant increase of the viscosity.Meanwhile,the sample showed obvious liquid faults,indicating its rancidity and metamorphosis.The whole soybean milk was used as raw material,and granulated sugar and malt syrup with mixing ratios of 2:2,2:5,2:8 and 2:11 were added,respectively.When the mixing amount was all limited at 15%,the increase proportion of malt syrup would decrease the concentration and accumulation density of whole soybean powder as well as wettability and dispersion,which was not conducive to the dissolution of the products.Sensory evaluation results also showed that the proportion of granulated sugar should not be excessively reduced.The ratio of granulated sugar and malt syrup was kept at 2:5,and the added amount of granulated sugar and malt syrup in whole soybean milk was adjusted to 5%,10%,15%and 20%respectively.The quality indexes of the whole soybean powder were optimized with the increase of the added amount of mixed ingredients,and the sensory score was also improved.The result of multiplicate experiments showed that the instant whole bean powder with good solubility and taste could be prepared by adding 15%granulated sugar and malt syrup with 2:5 ratio.In addition,according to the provisions of GB 7718-2011 national food safety standard "general principles for pre-packaged food labeling" and other standards,the pre-packaging labels of whole soya-bean milk and instant whole soya-bean powder were preliminarily designed to form the final product form.