Influence Of Ultrasonic Treatment On Structure And Functional Properties Of Low Purine Defatted Soybean Power

Low purine defatted soybean milk was developed by our team, which was used ultrasonic anddefatted soybean meal as raw material in the preliminary work. The influence of ultrasonictreatment on structure and functional properties of low purine defatted soybean power wasstudied by this article, the results of this study were as follows:1After testing analysis, the contents of purine, protein, fat and total sugar of defatted soybeanmeal were253mg/100g,47.90%,2.97%,31.60%. The contents of purine, protein, fat and totalsugar of defatted soybean power were145.00mg/100g,54.30%,1.32%,29.31%.2When ultrasonic power was450W, ultrasonic time was40min, ultrasonic temperature was50℃, the maximum of the protein nitrogen solubility index oflow purine defatted soybeanpower was69.24%, the maximum of foaming and foam stability were22.3%å'Œ35.6%, themaximum of oil absorption of low purine defatted soybean power was11.06g·g-1. Whenultrasonic power was405W, ultrasonic time was30min, ultrasonic temperature was50℃, themaximum of the emulsification was75.6%. When ultrasonic power was450W, ultrasonic timewas40min, ultrasonic temperature was40℃, the maximum of emulsion stabilitywas39.2%,the maximum of water absorption was5.64g·g-1. After ultrasonic power treatment, whenultrasonic power was360W, ultrasonic time was30min, ultrasonic temperature was50℃, theprotein of low purine defatted soybean power was formed a gel; After ultrasonic time treatment,when ultrasonic time was50min, ultrasonic power was450W, ultrasonic temperature was40℃,the protein of low purine defatted soybean power was formed a gel; After ultrasonic temperaturetreatment, when ultrasonic temperature was40℃, ultrasonic power was450W, ultrasonic timewas40min, the protein of low purine defatted soybean power was formed a gel.3When ultrasonic power was450W, ultrasonic time was40min, ultrasonic temperature was60℃, the lowest of viscosity oflow purine defatted soybean milk was0.1mpa·s. Whenultrasonic power was450W, ultrasonic time was40min, ultrasonic temperature was40℃, themaximum of water retention was92.38%. When ultrasonic power was450W, ultrasonictemperature was50℃, ultrasonic time was30min, the maximum ofsulfhydryl was8.75umol·g-1. When ultrasonic power was450W, ultrasonic temperature was40℃, ultrasonic timewas60min, the maximum of the surface hydrophobicity of protein was3.86%. After ultrasonic treatment, the volume average particle size of the low purine defatted soybean power was higherthan not ultrasonic treatment. Particle size distribution width greater than1.5, indicated the lowpurine defatted soybean power distributed unevenly. Ultrasonic power was from270W to405W, ultrasonic time was from20min to40min, ultrasonic temperature was from20℃to40℃,with the increase of ultrasonic power, time, temperature, the volume average particle size of thelow purine defatted soybean power reduced. Ultrasonic power was from405W to450W,ultrasonic time was from40min to60min, ultrasonic temperature was from40℃to60℃, withthe increase of ultrasonic power, time, temperature, the volume average particle size of the lowpurine defatted soybean power increased.4Using infrared spectroscopy (FT-IR) to measure the protein secondary structure of lowpurine defatted soybean power after different ultrasonic treatment. The results showed that:ultrasonic treatment changed the protein secondary structure of low purine defatted soybeanpower, when ultrasonic power was360W, ultrasonic time was30min, ultrasonic temperaturewas50℃, the maximum of the total content ofβ–folding and random coil structure were71.35%; The results of scanning electron microscopy (SEM) showed that the particle of lowpurine defatted soybean power was exhibited shriveled shape and the rugged ball structure,degree of aggregation was changed better, dispersion was changed poor.