Impact of Conventional Processing on Allergenic Proteins in Grasshopper-Based Meat Analog

Abstract

Edible insects are increasingly recognised as sustainable protein sources due to their high nutritional value and low environmental impact. However, the allergenic potential of insect-derived ingredients, particularly after processing, is still not well understood. This study assessed the effect of conventional processing on protein distribution and allergenicity in grasshopper (Valanga nigricornis) based meat analog compared with unprocessed grasshopper powder. Protein extraction using PBS (pH 7.4) separated samples into supernatant and pellet fractions, followed by protein quantification, SDS-PAGE profiling, and immunodetection with anti-tropomyosin and anti-arginine kinase antibodies. Pellet fractions showed higher protein concentrations in both grasshopper powder (48.56 mg/mL) and meat analog (69.04 mg/mL) than supernatants (4.03 mg/mL and 2.39 mg/mL), indicating predominance of insoluble proteins. SDS-PAGE revealed reduced solubility and increased aggregation in the processed analog. Western blotting detected tropomyosin (~36–38 kDa) mainly in the supernatant, with decreased intensity after processing. Arginine kinase (~40 kDa) appeared in both fractions, suggesting partial entrapment in the insoluble matrix. Overall, processing reduces but does not eliminate allergenic proteins, highlighting the need for thorough allergen risk assessment in insect-based meat analog development.