Abstract
The proximate composition, fatty acid profile, and lipid nutritional indices of the edible Huhu grub development stages (small, medium, large larvae, and pupae) of the New Zealand endemic beetle (Prionoplus reticularis), were investigated. Ash (1.5–3.2%, dry weight (DW)) and crude protein (26.2 – 30.5%, DW) contents were similar across the development stages. Lipid content was highest in pupae (58.4%, DW). Between 10 and 13 fatty acids were found in each of the four development stages. Palmitic acid (7.45 – 13.95 g/100 g DW), oleic acid (22.04 – 40.54 g/100 g DW), and linoleic acid (0.82 – 1.47 g/100 g DW) were the most abundant saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), and polyunsaturated fatty (PUFA) acid, respectively. The PUFA/SFA ratio ranged from 0.07 to 0.09, while the ω6/ω3 ratio ranged between 16.23 and 29.54. The hypocholesterolemic/hypercholesterolemic acid ratio ranged from 2.89 to 3.15. The atherogenicity indices ranged between 0.32 and 0.37, the thrombogenicity index range was 1.63 – 1.99, and the health-promoting index range was 0.07 – 0.11. Overall, the results of this study indicate that Huhu grub larvae and pupae contain relatively high levels of lipids, but they differ in their fatty acid profile and lipid nutritional indices.
•Proximate and lipid nutritional indices are reported for Huhu developmental stages.•Crude lipid was highest in pupae.•The abundant fatty acids were palmitic acid, oleic acid, and linolenic acid.•Huhu grubs at all development stages had high MUFA contents.•Small grub had the highest ratio of omega 6 to omega 3.