Influence of size reduction variation and fermentation time towards cyanide acid contents and phenolic compound in faba bean (Vicia faba) tempeh

Abstract

Indriyani CS, Handayani S, Rachmawati D. 2010. Influence of size reduction variation and fermentation time towards cyanide acid contents and phenolic compound in faba bean (Vicia faba) tempeh. Biofarmasi 8: 31-36. Tempeh is fermentation product wich very known by Indonesian society and has been familiar with various western society. Tempeh can be made from various ingredient, but usually, tempeh is made from soybean. Due to the increasing soybean price, it has been found another Leguminosae to substitute soybean. One of legume was faba bean, Leguminosae, that generally contains phenol as antioxidant and cyanide acid as antinutrient and toxic material. The aim of this research was to determine the effect of size reduction variation and fermentation time variation of faba beans tempeh production to cyanide acid and total phenol contents. This research used a factorial experiment that arranged in a Randomized Complete Design (RCD) with two experimental factors including size reduction (chopped and sliced) and the time of fermentation (0, 30, 36, 42 and 48 hours). The result showed that cyanide acid content in fermentation of 0, 30, 36, 42 and 48 hours on faba beans tempeh by chopped seeds were 0.060 mg/g, 0.048 mg/g, 0.036 mg/g, 0 mg/g and 0 mg/g, respectively, then on faba beans tempeh by sliced seeds were 0.072 mg/g, 0.036 mg/g, 0.036 mg/g, 0 mg/g and 0 mg/g, respectively. Meanwhile, the content of total phenol on faba beans tempeh by chopped seeds were 0.014750%, 0.149900%, 0.201825%, 0.170400% and 0.234400%, while on faba beans tempeh by sliced seeds were 0.014750%, 0.152650%, 0.178300%, 0.162750% and 0.192620%, respectively. The fermentation time and the size of faba beans seeds affected on cyanide acid and total phenol contents of faba beans tempeh. The longer fermentation time of faba beans tempeh caused lower cyanide acid content and higher total phenol content. The smaller size of faba beans seeds on tempeh caused lower cyanide acid content and higher total phenol content. The lowest cyanide acid content was contained in faba beans tempeh with chopped and sliced seeds with 42 and 48 hours fermentation reached 0 mg/g. The highest total phenol content was contained in chopped faba beans tempeh with 48 hours fermentation reached 0.234400%.