Document Type : Original Article
Authors
1
Food Science and Techno!. Dept., Fact. of Agric., Tanta, Tanta nlv.
2
Home Economics Dept., Fact. of Specific Education, Tanta Uni ., Egypt.
Abstract
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.
Keywords
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