EVALUATION OF TEMPE PRODUCED BY FERMENTATION OF SOYBEAN USING TWO SPECIES OF Rhizopus

Soybean was de hulled. soaked. autoclaved and fermented by two species of Rhizopus namely. R. o/igosp < /em>orus and R. arrhlzus .to produce tempe. Chemical. nutritional. microbiological and organoleptical evaluation of soybean lempe groducts were investigated. The best products were obtained after 26 and 30 hrs at ~1. 32·C by R. oligosporus end R. entuzus. respectively. II was noticed that. soaking and autoclaving processes decreased significantly (P S 0.05) contents of ether extract, ash, total carbohydrate, lotal solids, soluble solids. insoluble solids. TP, minerals. number of yeasts and lactic acid bacteria. On the contrary, moisture, crude protein and NPN contents were increased signifICantly (P ~ 0.05) in soaked-au oelaved soybean grits, while crude fiber content and total bacterial spores count did not change in the same grits. However, fermentation process either by R. o/lgosp < /em>orus or R arrhizus elevated Significantly (P s 0.05) contents of moisture. crude protein. NPN. crude fiber, soluble solids, counts of lactic acid bacteria and total bacteria spores. Conversely, ether extract, total carbohydrate, total solids, insoluble solids and TP contents were diminished significanlly (P !> 0.05) in tempe products. Fe and K contents increased slightly after fermentation process, but Ca, Cu and Na contents decreased slightly after this process. Conlents of Mg, Mn, Zn and yeasts cou~t did not alter appreciably after fermentation. Slight or no changes in the essential amino acids content were occurred as a result of tempe production. The most of essential amino acids were close to the amounts needed for protein balance according to t e FAO I WHO (1973)' reference protein. Sulfur-conlanirig amino acids gave the lowest score, although they were increased by fermentation. Chemical scores of essent (amino acids for lempe produced by R. arrhiws were higher than those for tempe fermented by R.o/igosporus with the exception of leucine. Data also indicated th t tempe produclion process improved significantly (P 50.05) the protein digestibility, C-PER and biological value. Moreover. trypsin inhibitor and phytic acid conte ts were diminished significantly (P s 0.05) as a result of tempe production. Finally sensory evaluation established that all fried tempe products were accepted.