Interesting Facts About Tempeh
Tempeh is an indigenous food from Indonesia, where it has been consumed as a staple for more than 300 years. It is a significant source of protein, vitamin B12, and other healthy bioactive compounds. Tempeh is made by fermenting various nuts, grains and beans with the Rhizopus species of filamentous fungus.
Fermentation Studies have shown that fermentation is the key that makes the food we eat super nutritious. Specifically, tempeh fermentation decreases anti-nutrient and allergen contents, whereas it increases essential micronutrient content, for example vitamin B12 and health-promoting compounds.
Sensory Characteristics The color of tempeh should be white, due to growth of Rhizopus, and limited black spots indicating the completely natural spore-phase of its life-cycle. The spores are completely safe to consume and lend tempeh an increased depth of flavor similar to aged camembert cheese. The flavor of tempeh should be meaty, mushroom-like, and nutty; never bitter. The odor of tempeh should be fresh, without a hint of ammonia. These are the qualities of fresh, high-quality tempeh.
Origin The earliest reference of tempeh was found in the Serat Centhini, a 17th century compilation of Indonesian legends, traditions, and teachings published in 1815 under the supervision of King Pukubuwono V of Surakarta Kingdom, Central Java, Indonesia.
Production The production of tempeh involves soaking the raw beans, cooking the beans along with any grains or seeds to be added, cooling the beans, grains and/or seeds, inoculating them with the Rhizopus culture, and then incubating the ingredients under specific environmental conditions (e.g. temperature, moisture, pH, oxygen and time) to facilitate the growth of Rhizopus. This growth increases the health-promoting potential of the beans, grains and seeds used to make tempeh by enhancing nutrient bioavailability and eliminating anti-nutrients by breaking down protein into amino acids, digesting lipids into fatty acids, transforming iron(II)-species into iron(III)-species, breaking down isoflavone glycosides into aglycones, reducing phytate content, as well as producing vitamin B12 through symbiosis.
Nutritional Content Compared to beef, tempeh is observed to be more favorable having more protein, less total fat, less saturated fat, more fiber, lower cholesterol, and higher calcium & iron levels and lower sodium content.
Effects of Tempeh Fermentation on Nutritional Content of Ingredients Tempeh fermentation is found to drastically increase the amount of soluble protein in tempeh made from chickpeas by 62.7%. In chickpeas, tempeh fermentation is also found to increase antioxidant activity and fiber content as well as decrease anti-nutrient (oligosaccharide) levels. In white and colored quinoa, tempeh fermentation increased the levels of protein by 15-20%, fiber by 48%,and free amino acids 5.5-9 %. A decrease in crude lipids is observed in chickpeas to be 38.9%, in peas 37.5,% and in black beans 12.5-25%. Tempeh fermentation also increases chickpeas’ total phenolic content 2.78 fold and antioxidant capacity 1.80- to 1.94-fold.
Health Benefits. The literature body on tempeh consists of evidence on the potential health benefits of tempeh on gut health, cancer, cognitive function, lung health, cardiovascular health, anemia, liver health, bone health, type 2 diabetes mellitus, obesity, skeletal muscle recovery, and malnutrition. Most of these health benefits in tempeh are linked to the isoflavone, protein, mineral, as well as para- and probiotic contents in tempeh.
Sustainability. The protein delivery energy score of tempeh is highly efficient compared to animal-based proteins showing to be 2 to 4-fold higher than various animal-based protein products. Similarly the protein delivery efficiency score of tempeh is 2 to 22-fold higher than animal-based protein products depending on the source.
Sources:
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Ahnan-Winarno AD, Cordeiro L, Winarno FG, Gibbons J, Xiao H. Tempeh: A semicentennial review on its health benefits, fermentation, safety, processing, sustainability, and affordability. Compr Rev Food Sci Food Saf. 2021;20:1717–1767. https://doi.org/10.1111/1541-4337.12710
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Photo Source:
Ahnan-Winarno, A., Winarno, W., & Nanere, M. (2019). Can tem- peh be greenly marketed by the Indonesian Tempeh Movement (ITM)? Proceedings of the Proceedings of the 1st Sampoerna University-AFBE International Conference, SU-AFBE 2018, 6-7 December 2018, Jakarta Indonesia. https://doi.org/10.4108/eai.6- 12- 2018.2286267