Tempeh

Tempeh. DehuUed cooked soybeans are inoculated with the mold, Thi pus oligosporus packed in perforated plastic bags, and allowed to ferment for 18 h. The mold mycelium overgrows the soybean cotyledons and forms a compact cake. When sHced and deep-fried in oil, a crisp and golden brown product is obtained. Although native to Indonesia, tempeh has become popular with vegetarians in the United States and other Western countries (93). 

Herbal products used for the relief of menopausal symptoms are purported to act by a number of different mechanisms. Phytoestrogens are plant sterols that are structurally similar to human and animal estrogen. Soy protein is a common source of phytoestrogens and can be found in products such as tofu, soy milk, soy flour, and tempeh. Various studies have demonstrated conflicting results as to the efficacy of... 

Uses of Soybeans as Foods in the West with Emphasis on Tofu and Tempeh... 

Soybeans have been used as food in the Orient since ancient times and various methods have been developed to make soybeans as palatable as possible. In recent years, a large number of these simply processed soyfoods are emerging in the West. Tofu and tempeh are the most popular and have the fastest growth rate of any soyfood in America. Tofu is made by coagulating the protein with a calcium or magnesium salt from a hot-water extracted, protein-oil emulsion of whole soybeans. 

It is a highly hydrated gelatinous product with a bland taste. The texture characteristics of the curds vary from soft to firm, depending on the processing conditions. Thus, tofu can be easily incorporated with other foodstuffs and used in nearly every culinary context from salad to dessert and from breakfast foods to dinner entrees. Tempeh is made by fermenting cooked soybeans with a mold, Rhizopus oligosporus. 

The white mycelium covers the bean mass and binds it into a firm cake that can be sliced, seasoned, and cooked just like meat. Tempeh is becoming a hamburger alternative for vegetarians. 

Tempeh Cooked soft beans bound together by mycelium as a cake, clean fresh and yeasty odor. Cooked and served as main dish or snack. 

Preparation. Traditionally, soaked, hand-dehulled and briefly boiled soybeans are inoculated with small pieces of tempeh from a previous fermentation, wrapped in banana leaves which also serve as a source of inoculum, then left at room temperature for 1-2 days. 

Niacin, riboflavin, pantothenic acid and vitamin B6 contents are greatly increased in tempeh during fermentation, whereas thiamin exhibits no significant change. H. oligosporus appears to have a great synthetic capacity for niacin, riboflavin, pantothenic acid, and vitamin B, but not for thiamin. 

Tempeh can be successfully fermented with common beans and bean/corn mixtures. However, the protein digestibility or nutritional quality of beans is not improved substantially by tempeh fermentation. 

Before 1990 the composition of isoflavones in soy foods was thought to be largely determined by whether the food had been fermented. Fermented foods (e.g., miso and tempeh) contain the unconjugated isoflavones agycones, while non-fermented food (e.g., tofu, soy flower, and soy milk) contain the conjugated glucoside. Subsequent experiments have demonstrated that fermentation of soy decreased the isoflavone content of the food product, but increased the urinary isoflavonoid recovery, suggesting that fermentation increases availability of isoflavones in soy (Slavin et al., 1998). 

Stillings and Hackler (54) studied the effects of the tempeh fermentation, the action of Rhizopus oligosporus on dehulled, soaked, and sterilized soybeans. The PER of tempeh reached its peak after 24 hours fermentation and then dropped. They ascribed the changes to an increase and then a decrease in tryptophan chemically present. The PER decrease after 24 hours was also attributed to an increased quantity of mold protein, which is lower in sulfur amino acid concentration than the original soy protein. Free amino acids increased markedly, presumably due to the action of the mold proteolytic enzymes. Free methionine was present in the largest amount, and as such was highly available, thus partially accounting for the initial increase in PER. 

Removal of the hulls is important to reduce oxalic acid content, increase protein content (72) and increase digestibility (74). Sesame proteinTas low solubility, and one method of increasing solubility is with partial enzymatic hydrolysis (75,). Hydrolysis with fungal enzymes increased the soluble protein content of sesame meal from 7.21 to 64.14%, values considered comparable to those in soy due to the tempeh fermentation. Increased lysine in the hydrolysis extract was accompanied by decreased methionine. 

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