Exploring the profile of amino acids and ethnography study in the biodiversity of tempeh as fermented foods of Indonesia

Tempeh has been world widely known as a functional food for several health benefits such as ACE inhibitory, hypotensive, and antioxidative. Although soybeans contained opioids, a peptide that affects mental state, there was no report on the potential of tempeh as a source of peptides with affective or cognitive function. This study examined the protein quality of tempeh as indicated by the amino acids profile and its possible role in improving depression, as indicated by the concentration of tryptophan and its ratio to large neutral amino acids (LNAA). Fresh tempeh types of different raw materials (soybean, okara, velvet bean, lablab bean, fresh coconut press cake) were collected from production areas. Samples were run for high-performance liquid chromatography. Results showed that protein and amino acid concentrations in tempeh ranged respectively from 13.97 and 8% ( gembus tempeh) and 45.5 and 18% (Malang tempeh). The amino acid score in all tempeh met the WHO standard for nine amino acids, indicating good quality of amino acids. Tempeh made from peanut press cake showed all amino acids scored higher than 100, while gembus tempeh showed three amino acids with a score of less than 100. Methionine was the limiting amino acid while glutamate was the predominant amino acid of tempeh. Except that in koro , gembus , or dage tempeh , tryptophan in tempeh samples showed the ability to serve as an anti-depressant activity.