The use of seaweed as sustainable feed ingredient for the house cricket ( Acheta domesticus): ): investigating cricket performance and nutritional composition

The house cricket ( Acheta domesticus) ) is considered one of the most promising farmed insect to be used as novel food, thanks to its attractive nutritional profile and its great taste. To the best of our knowledge, crickets in Europe are reared on soybean meal-rich feed which won't be sustainable in the long run. Insect producers have shown interest in using more environmentally friendly substrates for cricket's rearing. Among these, seaweed has been investigated as feed ingredients for insect rearing. However, no studies on crickets are available. We aimed to evaluate the potential use of the alga Palmaria palmata in the diet of house crickets (5%, 10% and 20% of the diet), in terms of insect performances and nutritional composition (protein, lipid, amino acids and fatty acids). Crickets fed seaweed-enriched diets showed good performance parameters (individual weight, cricket yield and survival) compared to crickets fed the control diet without presenting statistically significant differences (P P > 0.05), while their nutritional composition changed significantly for some components. Protein content of the crickets increased when more seaweed was added to their diets (P P = 0.0115), while the fat content decreased (P P = 0.0451). Also, the amino acid composition of the crickets remained stable between dietary groups, except for histidine, methionine and lysine which increased in crickets fed more seaweed in the diet (P P = 0.0430, P = 0.0342, P = 0.0302, respectively). Finally, the presence of seaweed in the diet led to a transfer of the omega-3 eicosapentaenoic acid from the seaweed to the crickets (P P < 0.0001), which are naturally lacking this fatty acid. Based on this study, we conclude that the red alga Palmaria Palmata is a suitable substrate for cricket mass rearing up to 20 g/100 g of the diet. However, higher seaweed inclusion and longer dietary administration time could affect the nutritional composition of the house cricket differently, therefore they should be investigated.