Impact of different preparations on the nutritional value of the edible caterpillar Imbrasia epimethea from northern Angola

In contrast to most European countries, raw and processed insects are a part of the traditional diet in Africa, especially among poor people in rural areas. This paper presents a first nutritional analysis of the caterpillar species Imbrasia epimethea (Drury), which is widely collected and eaten in the Uige Province, northern Angola. Major nutrients were analysed with focus on the impact of different traditional preparation techniques (evisceration, cooking and/or drying). The native larvae revealed similar nutritional values (protein and fat content, amino and fatty acid composition) as Gonimbrasia belina, another member of Lepidoptera, and a higher quality than mealworms and crickets. With respect to more Western diets, the protein content of I. epimethea was found to be similar to tuna, chicken and beef, while essential amino acid were lower, resulting in lower essential amino acid indices. Fat contents were lower than in chicken, tuna and beef. Its fatty acid profile, with high percentages of polyunsaturated fatty acids, makes it a valuable contribution to human nutrition. The different preparation methods had only limited impact on the nutritional composition of the caterpillars. The removal of the gut reduced carbohydrates originating from the leaves of the host plant, and thus significantly raised protein and (non-significantly) fat contents. Thermal processing had no significant negative effect on the nutritional value except for the decrease of monounsaturated fatty acids. Thus, I. epimethea represents a valuable traditional alternative to food from other animal sources, especially with regard to its fatty acid composition.