Lipid and amino acid profiles support the potential of Rhynchophorus phoenicis larvae for human nutrition

Abstract

In view of future use of insects in the diet, Rhynchophorus phoenicis larvae were evaluated for their potential as protein and lipid sources. Their lipid and protein contents represented 21.35±2.01g/100g and 8.18±0.44g/100g fresh weight (FW), respectively, with energy content of 940.0kJ (224.9kcal)/100g FW. Indispensable amino acids were in higher amounts than in Food and Agriculture Organization (FAO) reference protein, with remarkably high scores for tryptophan and sulfur amino acids. Total lipids comprised neutral lipids (97.53±0.05g/100g lipid), glycolipids (0.59±0.04g/100g), phospholipids (1.88±0.06g/100g) and tocopherols (146±13μg/g). Total and neutral lipids had palmitic and oleic acids (38 and 46g/100g total fatty acids, respectively) as main fatty acids, and palmitoyl, dioleylglycerol (POO) (36.4±0.3%) and dipalmitoyl, oleylglycerol (PPO) (30.3±0.3%) as main triacylglycerol molecular species. This composition explains the lipid melting/crystallization profile. Polyunsaturated fatty acids represented 0.76±0.17g/100g fresh larvae (linoleic acid: 0.58±0.11g/100g; alpha-linolenic acid: 0.17±0.06g/100g). They concentrated in the phospholipids, characterised by a majority of choline-carrying species and high levels of lyso-phospholipids. These results confirm that Rhynchophorus phoenicis larvae are a potential alternative source of dietary fat and proteins that can be used to address under-nutrition and malnutrition.