Nutrition And Safety Study Of Rhizopus Fermenting Soybean Food-tempe

In our experiment, fermenting measure of tempe could be definited initially as that soaking soybean for 18~24h——steaming soybean for 20min by 0.08Mp——mixing 0.8% lactic acid——suppling fungal inoculum——fermenting at 36(±1)℃ for 30h By way of measurement of the content of nitrogen-contained nutrition in tempe,it could be seen that both non-protein-nitrogen(N.P.N) ingredients and soluble protein in tempe increased significantly, comparing with that in the sample was not fermented．The N.P.N, α amino- nitrogen, peptide Nitrogen, the total content of its free amino acid and the NSI, water, ethanol soluble protein, in tempe increased about 12.7, 6.6, 38.9 times, 3 times, 4.51, 1.94, 1.30 times respectively. For tempe fermented for 48h, nitrogen contained-nutrition contents had not dramatic change, compared with tempe fermented for 30h． By virtue of measurement to content of lipids nutrition in tempe,it could be known that the total content of lipids in tempe fermented for 30h was almost the same as in the sample was not fermented．But the acid valve and iodine valve of lipids in tempe increased about 3.7 times and 0.15 times,and the contents of some kinds of free unsaturated fatty acids including oleic,linoleic,arachidonic,linolenic acids,improved 6.9, 3.4, 9.3 and 7.1 times respectively, comparing with that in the sample was not fermented．The change of them was not significant after tempe was fermented for 30h．By measurement to content of some water soluble vitamin in tempe,it could be found that vitamin B1,B2,B12 in tempe which had been fermented for 30h were 2.16, 1.71, 3.33 times of ones of beans not fermented, respectively. For tempe fermented for 48h, contents of vitamin B1, B2, B12 did not change significantly, compared with tempe fermented for 30h．Through some kinds of safety tests on tempe,it could be seen that lethal does 50%(LD50) >15.0g/kg,the results of microkermel test,spermatocytes chromosome aberration test,sperm malformation test and ames test all were negative．The contents of Pb,As and AFB1 all were beneath the standard of nation food safety. So,tempe was a kind of safe food．It could be known that total bacteria quantity and coliform group most probable number (MPN) of tempe that had been fermented for 30h are 4.1×107,<30 respectively, measuring them. However, they both increased and were 2.1×109,120 respectively, and MPN exceeded the standard of food fermented safety (MPN≦30), when tempe had been fermented for 36h.Candidate:Hao ChunleiSupervisor:Prof. Wang LiqunSpeciality:Preventative Veterinary Science...