A variety of indigenous fermented foods exist today; however, tempeh has been one of the most widely accepted and researched mold-modified fermented products. Tempeh is a traditional fermented food made from soaked, dehauled, and cooked soybeans inoculated with a mold, usually of the genus Rhizopus. The soybeans placed into a perforated type bag to make a compact cake for fermentation to occur. The soybean and/or other grains will turn the cake into a dense cottony mycelium form. An important function of the mold in the fermentation process is the synthesis of enzymes, which hydrolyze soybean constituents and contribute to the development of a desirable texture, flavor, and aroma of the product. The mold also forms the ‘cake’ for easy use in cooking.
Enzymatic hydrolysis also may decrease or eliminate anti-nutritional constituents; consequently, the nutritional quality of the fermented product may be improved. Current technology and new scientific advancements have enabled researchers to examine specific strains of Rhizopus and new substrates such as cereal grains. Because Kansas produces numerous cereal grains, production of a fermented tempeh-like product using wheat, sorghum (milo), oats, rye, barley, corn, and triticale is a definite possibility for generating a Kansas Value-Added Product. In this study, several different tempeh-like products were produced using various cereal grains inoculated with Rhizopus oligosporus NRRL 2549 or R. oligosporus NRRL 2710.
Grains used included hard red winter wheat, triticale, yellow sorghum (milo), and red sorghum (milo). The grain source as well as the strain of R. oligosporus used influenced the product's appearance, flavor, and patty integrity. Results showed that R. oligosporus NRRL 2549 produced more mycelium at a more rapid rate than did the R. oligosporus NRRL 2710 strain.
The combination of red sorghum and R. oligosporus NRRL 2549 yielded a product with good patty texture, aroma, and appearance. Furthermore, the red sorghum fermented product was well suited for slicing. On the other hand, yellow sorghum inoculated with either R. oligosporus NRRL 2549 or R. oligosporus NRRL 2710 failed to produce an organoleptically suitable product.
Triticale is an unacceptable substrate for the production of a tempeh-like product. Although the fermented wheat product had a desirable aroma and flavor, it lacked patty integrity and crumbled when sliced. Further research will evaluate the economic significance and industrial applications of these tempeh-like products.
Formation of vitamins by pure cultures of tempe moulds and bacteria during the tempeh solid substrate fermentation.
The formation of water soluble vitamins (vitamin B12, vitamin B6, riboflavin, thiamine, nicotinic acid and nicotinamide) during the tempe solid substrate fermentation was investigated. The role of several strains of Rhizopus oligosporus, R. arrhizus, and R. stolonifer and the role of several bacteria in the vitamin formation process were checked. All fungal and bacterial strains were isolated from Indonesian tempe and soaking water samples. The Rhizopus strains formed riboflavin, nicotinic acid, nicotinamide and vitamin B6. The final concentrations of these substances depended on the different strains involved and on the fermentation time. Isolates of R. oligosporus were generally the best vitamin formers. The moulds did not produce physiologically active vitamin B12. The thiamine content decreased during fermentation. The addition of bacteria, which had been selected in a screening for vitamin B12 production, resulted in an increase of physiologically active vitamin B12. Citrobacter freundii and Klebsiella pneumoniae showed the best formation capabilities. Furthermore, the bacteria produced riboflavin and vitamin B6 in addition to the moulds. The influence of Rhizopus on the vitamin B12 formation of Cit. freundii was also investigated. The vitamin content of tempe that was fermented with the mould and the bacterium was
three times as high as a control fermentation with
Cit. freundii only.
Got Culture Questions? Call the Culture Hotline...
Please Call 1+ 231.269.3261 Between 4PM - 8PM, GMT -5/EST. Copyright 2010-2016 Organic Cultures - Water Kefir Grains, Dairy Kefir Cultures, Kombucha/JUN strains, Japanese culture
spores for home food culturing.
Copyright protected under state, national, and international laws. All rights reserved. Images may be used/copied if www.organic-cultures.com
is quoted or linked as the source.
Contact webmaster at: webmaster (at) organic-cultures.com