Antioxidant Activities of Tempeh prepared with Black Soybeans

This study aimed to evaluate the potential of black soybeans (Seoritae) as a probiotic food ingredient through the preparation of tempeh. Seoritae, a black soybean variety, is known for its high content of anthocyanins and glycitein compared to white soybeans, and these compounds are widely reported to exhibit potent antioxidant properties. Tempeh was prepared using white soybeans as the control group (CON), while varying proportions of Seoritae and white soybeans were used to produce additional tempeh samples. The total polyphenol and flavonoid contents, antioxidant activity, pH, and color properties of the tempeh were analyzed. The results showed that the total polyphenol and flavonoid contents significantly increased with higher proportions of Seoritae. Furthermore, DPPH and ABTS+ radical scavenging activities, along with reducing power, demonstrated a proportional increase. The lightness (L* value) decreased as the Seoritae content increased, while the pH remained unaffected. This study provides foundational data for the development of probiotic food ingredients by assessing the antioxidant activity and quality characteristics of tempeh made with Seoritae as a fermented food.