Nutritional properties of giant water bug, Lethocerus indicus a traditional edible insect species of North-East India

Abstract

Edible insects play an important role in human health and food security. Among those, the Giant water bug, Lethocerus indicus (Lep.& Ser.) is a widely used edible insect known for its aroma, flavor, and therapeutic purposes. In the present study, we investigated the nutritional profile, natural habitat, and feeding behavior of L. indicus in aquarium conditions. A comparative analysis of male and female insects’ aroma contents and fatty acid (FA) profiles was also conducted. A dry fried male insect yielded volatile oil of 0.96%/2 g body weight, whereas a dry fried female yielded 0.48%/5.36 g of body weight. In terms of lipids, fresh male insects had 0.15%/5.42 g of body weight and fresh female insects had 0.28%/9.48 g of body weight. There are 24 volatile compounds specific to males, 37 specific to females, and 13 commons to both were identified. 2-Hexen-1-ol, acetate, (Z)- which smells like banana, was prevalently found in males while 4-Octene, 2,6-dimethyl-, [S-(Z)] was prevalently found in female insects. Fatty acids profile analysis detected 32 FA with 12 unique FA from males whereas 22 FA and 3 unique FA were identified from female insects. The SFA percentage present in males and females was 77.44% and 85.21%. Males had 6.78% MUFA content while females have 4.75%. Males have 18% PUFA content enriched with DHA, and EPA, while females had 10.04%. This study revealed that with the presence of a banana-like smell of volatile compound and more MUFA and PUFA in males, the native people of North-East India preferred male over female insects for entomophagy.