Preparation and components of Okara-ontjom, a traditional Indonesian fermented food

Abstract

In order to utilize okara (the insoluble residue of homogenized soybean) as a food stuff, scientific preparation and specificity of chemical components of Okara-ontjom (Ontjom, a traditional Indonesian food which was fermented by Neurospora intermedia) were studied. Prepared Ontjom was a porous compact block as like as a sponge cake, the surface of which was covered with orange colored spores of N. intermedia. The mycelium of the mold proliferated on and in the wall of soybean cells and connected with each pieces of okara, and consumed some components of the cell wall of soybean. Fundamental conditions of Ontjom's preparation were established as follows. Okara containing 60% moisture was pressed by 1.1 g/cm2 to give 2.5 cm in thickness and was sterilized at 121°C for 20 min, and then ontjom starter containing N. intermedia mold spores was evenly sprinkled over okara. After germination of spores, at 30°C for 18 hours with a fitted cover, the incubator cover was changed with a double layer nylon gauze (30 denier, 105×99/inch2) and incubation was continued at 25°C in 65% humidity for about 11 hours. Detecting sporulation, the medium was inverted. After the change of surface color to orange, the medium was allowed to stand for about 35 hours more. The component changes from okara to Ontjom were as follows. The protein content increased to 27% from 22% and was digested to smaller particles. The fat content decreased to 9% from 15% and the insoluble dietary fiber content decreased also. Ontjom had not the soybean-like flavor. The touch in mouth was smooth. The taste of fried Ontjom was resembled that of chicken. Consequently, Ontjom should be useful as a new tasted low-energy food material.