| In the traditional tofu making process, not only soybean residue is generated, but also whey water discharges, which reduces the utilization of nutrients contained in soybeans, and the discharge of waste water has caused severe environmental pollution. Main research objective of this paper was to explore the new tofu processing of non-residue and free compression with low temperature meal to improve the use of soy nutrients, the further purpose was conducive to environmental protection, as well as providing a new way of in the development and utilization of soybean meal.Due to explore the non- residue process conditions, the experiment started with the theoretical analysis of the effect of dietary fiber on protein gel network formation. The micro-grinding bean dregs were added to the soy protein isolate serous to produce tofu, and the effects of amount of dietary fiber on tofu-gel and retention was examined. The results showed tofu color became pale yellow from creamy white as the okara content increased. When the dietary fiber content was about 12%, the insoluble fiber ingredients had seriously affected the gel properties of soy protein, the overall acceptability was poor. The paper also measured the tofu-gel properties, in the main indicators, the breaking stress of 15-23Kpa, flexible 0.75-0.95, retention 78%-82%, the quality of measurement were consistent with the traditional tofu-gel results. Taking the value of dietary fiber on human health into account, content less than 10% would not affect the sensory acceptability of tofu products.This study also examined the effect of type and content of lipids on the quality of tofu gel. Results showed the products added with lipids were more slippery, chewiness was improved, and the network structure was more closely. Content of 0.25%-0.5%, the tofu had higher gel strength and water retention, and the hardness of tofu was more acceptability, also viscoelasticity was better; main function of lipid on the protein gel was to improve taste and chewiness, and to increase gel rupture stress, flexibility and retention.According to the above theoretical analysis of effect of dietary fiber on soybean protein gel texture, the new tofu processing technology (non-residue-free pressed) was feasible, so this paper explored the processing conditions using low-temperature soybean meal as a raw material: 1.First of all, through orthogonal experimental design, the most suitable pulping conditions filtered were: soybean crushing 40 mesh, soaking temperature 40℃, soaking time 5h, the amount of alkali 1.0%; 2.The compound additive ratio of the production process of tofu was 0.45% calcium sulfate, magnesium chloride 0.3%, agarose 0.8%, and 1.5% sodium alginate; 3.The best conditions for freezing tofu obtained: feed-water ratio was 1:5, boiled pulp temperature 95℃, boiling syrup time 15min, solidification temperature 90℃; regarding to tofu hardness, gel strength and water holding capacity, solidification temperature was the most influential factor, followed by pulp cooking time, and milk concentration and boiling slurry temperature was less affectedWhen lipid was added to meal tofu, there was some improvement in the quality of gel, and the gel properties, such as breaking stress, flexibility and retention improved. In addition, the results were consistent with the theory above, the effect of lipids on the quality of tofu gel with soy protein isolate. Adding 10% of the amount of the sweet potato starch, taste of soybean meal tofu was improved, their degree of lubricants increased. The soybean products with this process compared with compared tofu with soy beans by the traditional system, was low in fat and high dietary fiber content, better retention of nutrients. The process used to make tofu and its products by soybean meal is promising.
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