Inhibiting post-harvest perishability of edible beetle grubs (Oryctes spp) by blanching and pre-treatment with sodium metabisulphite and ascorbic acid

Abstract

Although edible beetle grubs (Oryctes spp) are highly nutritious, post-harvest perishability limits their utilization in food processing. This study investigated the effects of blanching singly or in combination with either ascorbic acid or sodium metabisulphite or a blend of the two chemicals, on colour, microbial quality, protein quality, total phenol content and amino acid composition of the grubs after harvest. All the pretreatments effectively preserved the colour of the grubs, reduced protein oxidation and inhibited most harmful microbes to food safety limits. The treatments had insignificant effect on amino acid profiles of the larvae. Combining blanching with ascorbic acid eliminated Staphylococcus aureus from the larvae and outperformed the other treatments in enhancing the content of total phenols. The findings provide prospects for preservation of the edible beetle grubs using the affordable, readily available, and easy-to-apply heat and chemical pretreatments prior to processing into other palatable food products.