Insect Lipids as Novel Source for Future Applications: Chemical Composition and Industry Applications-A Comprehensive...

Nutritional values of some insects are correlated with species, developmental stages, temperature, reproduction, flight, migration, and their diet. Insect oil may be utilized as an ingredient in feed and food, in the cosmetic industry, or as biofuel. Lipid content is composed mainly of fatty acids (FAs) of nutritional importance. Insects' fat body (FB) is crucial for lipid synthesis, accumulation, and hydrolysis. Triacylglycerol (TAG) accumulation occurs mainly in adipocytes. The major transported lipid is diacylglycerol, which is carried by high-density lipoprotein (lipophorin [Lpp]) from the gut into a trip to tissues for storage and utilization. About 1900 insect species, mainly from the Coleoptera, Lepidoptera, Hymenoptera, Orthoptera, Hemiptera, Isoptera, Odonata, and Diptera orders, were recorded to be consumed by humans in the world, particularly in Asia, Latin America, and Africa. Different methodologies used to extract lipids are currently applied to insects, such as the aqueous extraction, the Soxhlet method, the Folch method, the Matyash method, the supercritical fluid extraction method, the Aqueous Enzymatic method, and the acid fermentation method. This review shows that the Coleoptera, Lepidoptera, and Isoptera orders contain the higher amount of fat/oil at the same level as palm and palm kernel oil. In the larval stage, Samia ricini had the higher fat content in terms of crude fat, followed by Rhynchophorus phoenicis, Rhynchophorus ferrugineus, commercial palm oil, Aspongopus viduatus (adult), Oryctes owariensis (Larvae), and Macrotermes nigeriensis (Adult) and palm kernel oil. Understanding lipid metabolism, composition, and physiological implications is fundamental for insect mass rearing and harvesting according to the final use target. This review aimed to contribute to knowledge about insects as sources of fats and FAs. Lipids from insects could play an important role as a source of energy if incorporated into human diets and make a valuable integration into feed and food as long as they are safe, legal, and accepted.