Study On The Fabrication Process And Mechanism Of Symplocos Sumuntia Tofu

Tofu, which is a high-quality plant protein food, nutrient-rich and unique flavor, as a traditional food of our country, has more than two thousand years of history. There is a a kind of traditional tofu in Hakka mountainous area of Fujian province, which is characterized by using the water boiled with leaves to pointing soymilk. In this way, not only made out of tofu contain food additives, but also having good water retention properties, microstructure and delicate and rich flavor. Local people believe that it’s fit for gallbladder and kidney stones patients to eat. In order to develop this traditional food, in this paper we used DNA barcode technology to identify leaves and ICP-MS to study its extract composition, optimizing the production process parameters and discussing the coagulation mechanism of Symplocos Sumuntia tofu. The main contents are as follows:(1) Identification of Symplocos sumuntia leavesIt met Symplocos Sumuntia botanical characteristics for morphological identification and identified by molecular biology, using DNA barcoding analyzed DNA fragments, whose results supported the species as ’Symplocos sumuntia Buch.-Ham. ex D. Don’. Identification accuracies were respectively100%,100%and99%. Combination of ancient literature, we confirmed this tradition was Symplocos sumuntia tofu.(2) Optimization of the production process for Symplocos Sumuntia tofuIn the basis of single-factor test, we researched the effect of the amount of Symplocos Sumuntia extract, temperature of pointing soymilk and coagulation time to the texture, water holding rate and sensory evaluation of Symplocos Sumuntia tofu. And we found the impact of various factors on hardness and sensory quality of Symplocos Sumuntia tofu were consistent, and the order from small to large was the amount of Symplocos sumuntia extract> coagulation time> temperature of pointing soymilk. While considered holding water, coagulation time was the most effecting factor, followed by Symplocos sumuntia extract, and the minimum impacting factor was temperature of pointing soymilk. By comprehensive analysis, we determined the optimum production process for Symplocos sumuntia fofu was1.5%,80℃,60min. Tofu has good quality and flavor in this process conditions. (3) Analysis the component of Symplocos Sumuntia leaves, Symplocos Sumuntia extract, Symplocos sumuntia tofu, and discussing the coagulation mechanism of Symplocos Sumuntia tofu.By analysis the composition Symplocos Sumuntia leaves, extract and tofu, the result showed that Symplocos Sumuntia leaves and extract had high levels of aluminum, the pH of Symplocos Sumuntia extract and recycling extract were4.4and5.7. So we suggested that Symplocos Sumuntia extract composite coagulant (acids coagulant and salts coagulant); but the aluminum residues in the tofu was higher than191mg/Kg, which would lead to health risks need further evaluation.(4) Quality comparison of Symplocos Sumuntia tofu, brine tofu and lactone tofuCompare the differences of Chemical composition among Symplocos Sumuntia tofu, brine tofu and lactone tofu, it showed that there were not significant (p>0.05) except moisture and protein content (p<0.05). Symplocos Sumuntia tofu had the highest protein content and the moisture content, and its moisture was between the brine tofu and lactone tofu. Compared with the other two tofu, we found tofu made with Symplocos Sumuntia extract had delicate structure, higher water holding rate, higher elasticity and was moderate hardness, and soft but not loose.