Rhinoceros beetle (Oryctes sp.) larvae as a nutrient rich delicacy: a comparison of nutrient profiles from four counties in western Kenya

Abstract

The nutritional value of larvae of the rhinoceros beetle, Oryctes sp., a popular delicacy and source of animal feed in western Kenya is unknown. This study aimed to determine the nutritional composition of Oryctes sp. larvae consumed in western Kenya and compare the nutrient values across four sampling counties i.e. Busia, Bungoma, Trans Nzoia and Kakamega. The hypotheses tested were: (1) the beetle larvae were rich in nutrients including moisture, crude protein, crude fibre, crude fat, carbohydrates, minerals, flavonoids and vitamins; and (2) these nutrient values were not affected by the county of collection of the samples. The nutritional values of triplicates of larval samples collected from the four counties were analysed using standard chemical procedures and compared using one-way analysis of variance. The larvae contained approximately 18, 42, 2, 1, and 19% moisture, crude protein, crude fibre, crude fat and carbohydrates on dry matter basis, respectively. Nine minerals namely magnesium, iron, zinc, calcium, copper, aluminium, cobalt, manganese and sodium were detected in the larvae at approximately 493, 26, 14, 267, 3, 14, 1, 9 and 221 mg/100 g, respectively. Furthermore, appreciable levels of flavonoids and vitamins A, E, nicotinic acid, nicotinamide, B2, B5, B6 and B9 were recorded in the larvae. The nutritional composition of the larvae was unique in each county, thereby providing opportunity to use insects from different sites for specific nutritional needs of consumers. The nutrient contents of the larvae were comparable or superior to that of conventional food sources. The larvae were particularly richer in flavonoids than most conventional foods which are currently relied upon as sources of dietary flavonoids. The beetle larvae are therefore vital in fighting malnutrition.