Physical characteristics of the seeds of soybean (Glycine max) varieties and the effect of fermentation time on the chemical characteristics of tempeh

Abstract

Abstract. Suhartanti PD, Handajani S, Nandariyah. 2019. Physical characteristics of the seeds of soybean (Glycine max) varieties and the effect of fermentation time on the chemical characteristics of tempeh. Cell Biol Dev 3: 13-18. Soybean is the main raw material for making tempeh, and so far, the raw material for tempeh is imported soybeans. Therefore, Indonesia needs to develop soybean varieties to overcome this matter. The soybean varieties are expected to be processed into tempeh with good physical and chemical properties. This study aims to determine the effect of different varieties on the physical characteristics of soybean seeds and fermentation time on the chemical characteristics of tempeh. The research design was a completely randomized design (CRD) with a factorial pattern consisting of two factors, namely soybean varieties (Grobogan, Argomulyo, Seulawah, Anjasmoro, Burangrang, and Galunggung) and variations in fermentation time (30, 42, and 54 hours). The results showed that the difference in varieties did not affect the color of the tempeh. Different varieties affect seed weight, water absorption, and swelling power of soybeans. Soybean varieties that have the best physical characteristics (highest water absorption and swelling power) are Grobogan. Variations in fermentation time affect the chemical properties of tempeh. Longer fermentation time will increase the tempeh's water, ash, and total protein content but decrease the fat and carbohydrate content. The soybean variety with the best chemical characteristics (highest protein content) is Galunggung. The soybean seed coat is yellow and greenish-yellow, and the color of the tempeh is white. The biggest weight is the Grobogan var of 24.14 g, and the largest water absorption capacity of the Grobogan var is 188%. Therefore, the biggest swelling power of Grobogan var is 150%. Based on the time of fermentation, the highest water content of tempeh was found in Grobogan var (54 hours), with 67.33%. The highest ash content of tempeh was in Anjasmoro var (30 hours), with 1.97%. The highest fat content of tempeh was in Galunggung var (30 hours), with 8.89%. The highest protein content of tempeh was in the Galunggung var. (54 hours) with 25.17%%. The highest carbohydrate content was in the Seulawah var (42 hours), with 11.43%.