Tempeh is one of the most popular soybean-based food products and is known to have several health benefits. Although several studies have analyzed the antioxidant properties of tempeh, the effect of different soybean varieties on the antioxidant properties of tempeh has not been studied. The aim of the present study is to evaluate the effect of different soybean varieties in Taiwan, namely Kaohsiung No. 9, Kaohsiung No. 10, Tainan No. 10 and Tainan No. 4, on the antioxidant compounds (phenolic and isoflavone contents) and antioxidant activities (ferrous ion chelating activity and ABTS radical scavenging activity) of tempeh. Tempeh made from Tainan No. 10 and Kaohsiung No. 9, which had bigger seed size, had the highest mold growth, while Tainan No 4 produced tempeh with the least mold. Tainan No. 10 showed the highest increase in total phenolic compounds after fermentation, while Tainan No. 4 showed the lowest increase. Moreover, pre-fermented soybean and tempeh made from Kaohsiung No. 9 showed the highest ferrous ion chelating properties but the lowest ABTS radical scavenging activity, while Tainan No. 4 showed the highest ABTS radical scavenging activity but lowest ferrous ion chelating properties. Of the four soybean varieties, Tainan No. 4 is the least suitable soybean for tempeh production.
View Full Article