Tempeh Antioxidant Activity using DPPH Method: Effects of Fermentation, Processing, and Microorganisms

Abstract

Tempeh is the main type of traditional Indonesian food that is processed from soybeans fermented by Rhizopus microsporus. This study aims to measure the antioxidant activity of some kind tempeh using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Measurement of antioxidant activity toward tempeh took directly from the producer, tempeh produced on a laboratory scale using Rhizopus spp., Bacillus spp., and Klebsiella sp. K110, tempeh fried and steamed, and tempeh during the fermentation stage. The results showed that the fermentation process soybeans into soybean increase antioxidant activity. The antioxidant activity of tempeh from producers varies between approximately 52-70%. It is because of tempeh fermented at uncontrol conditions so that the microorganisms involved in the fermentation time is also uncontrol. Potential microorganisms vary in determining antioxidant activity. In the group of Rhizopus spp. (ATH 35, ATH 24, ATH 53), it showed that the highest antioxidant activity was found in ATH 35 (84%). In the group of Bacillus spp. the highest antioxidant activity produced by B. megaterium (76%) and higher than the Klebsiella sp. K110 (75%). Thus, the fermented soybeans into tempeh increase antioxidant activity. The existence of the antioxidant activity of tempeh was affected by strains of microorganisms involved during fermentation and processing time that will be consumed.