Functional properties of tempe protein isolates derived from germinated and non-germinated soybeans

Abstract

Tempe is an indigenous Indonesian soybean fermented food. Tempe is a source of protein which can be used as a raw material for making protein isolate. In this study, the tempe was produced from Grobogan local soybeans with two types of treatment, germinated and non-germinated. The two types of tempe produced were then processed into protein isolates, namely tempe protein isolate from non-germinated soybeans (NGTI) and tempe protein isolate from germinated soybeans (GTI). This research aimed to measure the functional properties of NGTI and GTI and then compared them to CSI (commercial soy protein isolate). The results of this study showed that the functional properties of GTI and NGTI were not significantly different. Still, GTI had significantly higher values (p < 0.05) than CSI on the parameters of water absorption capacity (5.86 and 1.57 g water/g sample), oil absorption capacity (2.48 and 1.19 mL oil/g sample), foam capacity (133.50 and 120.00%), foam stability, emulsion stability, and gel strength. From this study, it can be concluded that GTI and NGTI have good functional properties that have an opportunity to be applied in the food industries as a substitute for CSI.

Tempeh: A semicentennial review on its health benefits, fermentation, safety, processing, sustainability, and affordability

“…Compared to tempeh flour, tempeh protein isolate had higher protein content (by 50.5%) and amounts of essential as well as nonessential amino acids and lower levels of crude fat, total carbohydrate, total ash, moisture, and crude fiber (Syida et al., 2018). Germinating soybean before being processed into tempeh protein isolate increased protein content by 5% to 7% and protein digestibility by 1.2%, while decreasing fat content by 1.3% to 1.5% (Astawan et al., 2019).…”

“…Germination also lowered phytic acid content and increased antiradical activity in soybean (Puteri et al., 2018). In a protein isolate form, tempeh made of germinated soybeans had significantly higher in vitro protein digestibility by 1.2% compared to tempeh made of nongerminated soybeans (Astawan et al., 2019).…”

Penambahan putih telur sebagai peningkat protein pada tempe kedelai

“…Asam amino yang terdapat di dalam tempe cukup tinggi dan lengkap jenisnya, serta mudah dimanfaatkan oleh tubuh, salah satunya yaitu mampu mengatur rasio hormon insulin. Tempe juga mengandung mineral yaitu kalsium, magnesium, zat besi, kalium, natrium, mangan dan tembaga yang penting dibagi metabolisme tubuh manusia (Astawan et al, 2020).…”

Effect of Tempeh and Daidzein on Calcium Status, Calcium Transporters, and Bone Metabolism Biomarkers in Ovariectomized Rats

“…Astawan et al [25] conducted a 90-day intervention study investigating the impact of various protein sources and levels on calcium absorption and retention, as well as serum and bone calcium content. Interestingly, their findings indicated no significant differences in these parameters across different protein sources and levels in the diet.…”