No abstract

No abstract

No abstract

The amino acid profile, techno-functionalities (foaming stability/capacity, emulsion stability/capacity, solubility, and coagulation), and physicochemical characteristics (colour, particle size, surface hydrophobicity, Fourier-transform infrared spectroscopy, and differential scanning calorimetry) of protein extracts (PE) obtained from Prionoplus reticularis (Huhu grub) larvae (HLPE) and pupae (HPPE) were investigated. Total essential amino acid contents of 386.7 and 411.7 mg/g protein were observed in HLPE and HPPE, respectively. The essential amino acid index (EAAI) was 3.3 and 3.4 for HLPE and HPPE, respectively, demonstrating their nutritional equivalence. A unique nitrogen-to-protein conversion constant, k, and the corresponding protein content of the extracts were 6.1 and 6.4 and 72.1% and 76.5%, respectively. HLPE (37.1 J/g) had a lower enthalpy than HPPE (54.1 J/g). HPPE (1% w/v) exhibited a foaming capacity of 50.7%, which was higher than that of HLPE (41.7%) at 150 min. The foaming stability was 75.3% for HLPE and 73.1% for HPPE after 120 min. Both protein extracts (1% w/v) had emulsifying capacities that were 96.8% stable after 60 min. Therefore, protein extracts from Huhu larvae and pupae are of a good nutritional quality (based on their EAAI) and have techno-functional properties, such as foaming and emulsification, that afford them potential for certain food technology applications.

Prionoplus reticularis larvae ('Huhu grubs'), a traditional food in New Zealand, have been grown commercially. However, no information is available on the composition or safety of the larvae as a food. A proximate analysis (58.7-75.2% moisture, 26.2-30.5% protein, 32.1-58.4% fat, and 1.5-3.2% ash dry weight basis) found that Huhu grubs contain substantial amounts of nutrients. Forty minerals were investigated for four different development stages of wild harvested Huhu grubs (small, medium, and large larvae and pupae). ICP-MS detected 28 minerals, (11 essential, 13 non-essential, and four heavy metals). The most abundant minerals were manganese, magnesium, phosphorus, iron, copper, and zinc. The heavy metal content of Huhu grubs was found to be below detection levels for arsenic and vanadium, but cadmium and lead were detectable. The results indicate, on the basis of proximate analysis and mineral content, that moderate consumption of New Zealand wild harvested Huhu is safe and nutritious.