Study On The Bio-coagulants Of Tofu And Its Application

This study investigate the main effects and interaction of MTG and several water-soluble edible hydrocolloids on hardness of LAB-contained tofu with whole soy cotyledon.Then chose the best carrageenan that was used to LAB-contained tofu with whole soy cotyledon together with MTG.Tofu gel had improved and the cost was reduced. Main results were as follows:1.The producing method of tofu prepared with whole soy cotyledon: Soybeanâ†'cleaningâ†'immersion(15℃,12h)â†'peelingâ†'grind to slurryâ†'add 7%of the sugar(m/v)â†'colloid milling(twice)â†'high pressure homogenizer(35 Mpa twice)â†'108℃, 10min sterilizingâ†'soybean milk with whole soy cotyledonâ†'add coagulant(MTG and suitable edible hydrocolloids),inoculate LABâ†'mixed evenlyâ†'42℃fermentâ†'4℃,12h ripeâ†'products2.Two factors factorial experiment design was used to investigate the main effects and interaction of MTG and various edible hydrocolloids(including carrageenan,pullulan, xanthan,pectin)on hardness of LAB-contained tofu with whole soy cotyledon.The results showed that:the gel hardness of tofu significantly increased with increasing MTG levels.Carrageenan addition had a significant impact on the gel hardness of tofu dealed with MTG,and in the range of experimental concentration,the hardness value was higher.Pullulan addition could significantly increased the gel hardness of tofu dealed with MTG,But in the range of experimental concentration,the hardness value was lower.Xanthan and pectin addition could significantly destroyed the gel of tofu dealed with MTG,respectively.3.Carrageenan was applied to LAB-contained tofu with whole soy cotyledon,together with MTG.On the basis of single factor experiments,we determined the optimal range of the carrageenan concentration,MTG concentration,the ratio of water to bean and the amount of inoculation.The optimal production formula by the orthogonal experiment was:carrageenan dosage was 0.05%,MTG dosage was 0.1%,the ratio of water to bean was 9:1,the amount of inoculation was 10~5cfu/mL.After optimized,the average hardness of tofu was 46.016g,the ratio of water holding was 86.5%,and the logarithm of the concentration of LAB was 7.601 after storage at 4℃for 70 days.4.The survival ability of LAB in tofu prepared with whole soy cotyledon was observed every 10 days during the storage at 4℃.The result showed that,the LAB counts increased in the beginning,then decreased.At the beginning of storage,the LAB counts could get to 10~8cfu/g.It could reach the largest counts after 10 days,then decreased slowly.It was 10~7cfu/g after 80 days,then decreased fast.After 10 days,it was less than 10~5cfu/g.