Title : The insects as a novel protein source: Nutritional, physicochemical properties and allergenicity of Mexican sphenarium purpurascens
Abstract:
The edible grasshopper Sphenarium purpurascens has emerged as a sustainable source of protein in Mexico. This study characterized the morphometric parameters (weight, length, width, and thickness), pH, physicochemical properties, and allergenicity of adult specimens collected from three locations in central Mexico (State of Mexico: M, Puebla: P, and Tlaxcala: T). Significant differences (p ≤ 0.05) were observed in size and weight among grasshoppers from the three regions, with specimens from P being heavier and longer than those from T. There was no difference in pH values among the samples (5.71–5.78), suggesting a minimal impact of geographic origin on acidity. The protein content on a dry matter basis was 70–79%, ash 4.0– 4.3%, fat 7.5–11.5%, fiber 7.8–10.1%, and carbohydrate 1.2–7.1% in the different grasshoppers; these results suggest a significant impact of location. The proteomic profile of S. purpurascens identified 37 proteins with allergenic potential, predominantly muscle proteins (myosin, tropomyosin, and troponin), which is consistent with their biological function and nutritional value, given that these proteins are rich in essential amino acids and contribute significantly to the overall desirable protein content in edible insects. A comparative analysis revealed that 86.5% of these proteins were present in all populations, suggesting that the allergenic profile is independent of geographic origin. It is noteworthy that peptidyl-prolyl cis-trans isomerase was detected exclusively in M, while hexamerins, tropomyosins, and myosins were present in all samples. Reports indicate the presence of these allergens in edible insects and arthropods, associated with potential cross-reactivity risks. These results contribute to understanding the variability in the composition and properties of S. purpurascens and provide data for risk assessment, offering reference information for its incorporation into insect-based foods. The results also highlight the importance of regional selection for standardizing proteins from this insect for food applications.
