Composition and nutritional evaluation of Aspergillus oryzae biomass grown on palm oil processing effluents

Abstract

Aspergillus oryzae biomass grown on effluents produced during the extraction of palm oil was found to have a crude protein content of 39.6 g 100 g⁻¹ and a ‘true protein’ content of 32.1 g 100 g⁻¹. Amino acid analysis showed that the essential amino acid content was 58.2 g 16 g⁻¹ N and the essential amino acid index was calculated to be 87.4. The sulphur‐containing amino acids were present at a combined level of 2.8 g 16 g⁻¹. In rat feeding trials the biomass had a biological value of 0.68 ± 0.03, a net protein utilisation of 0.65 ± 0.05 and a true digestibility of 0.96 ± 0.05 based on its crude protein content. No unusual fatty acids were detected in the biomass.