Effect of dehulling, cooking and roasting on the protein quality of Perilla frutescens seed

The effect of processing on the protein quality of Perilla frutescens was investigated. The amino acid scores for Perilla wholeseed and dehulled seed (kernel), as compared to the FAO/WHO/UNU (1985) amino acid requirement for preschoolers were 63 and 66, respectively. Net protein ratio (NPR), net protein utilization (NPU) and true digestibility of protein (TDP) of Perilla wholeseed as well as kernel in the raw, roasted or cooked forms were evaluated using rat balance assay. Compared to the casein based control diet (NPR 4.8, NPU 79.8, TDP 94.2), all the parameters examined were significantly (p<0.05), lower in the Perilla diets (NPR 1.7-3.9, NPU 36.2-65.9, TDP 72.8-87.9). Cooking increased the NPR, NPU and TDP significantly (p<0.05), whereas roasting exerted a negative effect. Dehulling significantly (p<0.05) increased the NPR, NPU and TDP. This study demonstrates that Perilla seed is a source of good quality protein that could be used in both human and animal nutrition. (C) 1998 Elsevier Science Ltd. All rights reserved.