Bombyx mori Silkworm Pupae Protein Isolate and Its Application on High Protein Powdered Milk

Abstract

High protein food consumption is a new trend in society with busy life to fulfill the balance of daily protein need. A product with high protein content is high protein powdered milk (HPPM) for instance which commonly use high protein fortificant added through its processing. Bombyx mori silkworm pupae (BSP), by-product of silk spinning industry, has potential to be developed as an alternative for cheaper high protein fortificant. Previous research had isolated BSP protein to obtain protein isolate then fortified it into powdered milk. The continuing study is needed to produce pure protein isolate in order to produce HPPM with better characteristics. The two inventions applied in this protein isolation method were defatting and modifying pH on protein extraction and precipitation process. Hexane was used to extract powdered pupae fat. Protein extraction by NaOH 2N until pH 11 and precipitation by HCl 2N until pH 4.1 were used in this research to make sure all the protein fractions of BSP were dissolved in alkaline condition and precipitated as below its isoelectric pH. The objective of this research was to study the properties of Bombyx mori silkworm pupae protein isolate (BSPPI) and its application on HPPM. The results showed that defatting process could decrease 60.87% fat content of powdered pupae. The modified protein isolation method was able to produce pure BSPPI with 81.84% protein content. Fortification of 20% BSPPI showed very high significant difference (P<0.01) on protein content and protein digestibility of powdered milk, 40.44% and 95.15% respectively.