Microbiological Assessment and Shelf-Life Determination of Wheat Muffins Enriched with Domesticated African Emperor Moth (<i>Gonimbrasia zambesina</i> Walker) Caterpillar Flour

Abstract

African emperor moth (Gonimbrasia zambesina) caterpillars are considered healthy food as they are rich in protein and unsaturated fats. In Kenya, G. zambesina caterpillars are predominantly found along the coastal region, where they emerge in during the short and the long rains. The caterpillars forage in the wild on mango (Mangifera indica) leaves and Euclea natalensis (Ericales: Ebenaceae) leaves. The caterpillars are consumed whole or may be transformed into fine flour. The caterpillars’ flour can be utilized in the bakery industry for the enrichment of bakery products since wheat (the major component of bakery products) is low in protein. However, consumers are concerned about the microbiological quality of bakery products enriched with insect flour. There are also concerns about the effect of these insects’ flour on the shelf life of bakery products since they have unsaturated fats. Therefore, this study evaluated the microbial quality and shelf life of wheat muffins enriched with G. zambesina caterpillar flour at 0%, 5%, 10%, 15%, and 20%. For all the samples analyzed, total viable count (TVC) was Salmonella spp, and Staphylococcus aureus were not detected. The colonies for yeast and moulds were an increase in the substitution level. The PVs of enriched wheat muffins increased with an increase in storage time and temperature. The shelf-life of the wheat muffins decreased with an increase in the substitution level of wheat flour with G. zambesina caterpillar flour. The predicted shelf life of 0%, 5%, 10%, 15%, and 20% wheat muffins was 120.0 days, 111.0 days, 103.0 days, 102.0 days and 90.0 days, respectively. Therefore, wheat muffins enriched with G. zambesina caterpillar flour have good microbiological quality and shelf life.