Toward the design of insect-based meat analogue : The role of calcium and temperature in coagulation behavior of Alphitobius diaperinus proteins

Abstract This study focused on the coagulation behavior of protein from larvae of Alphitobius diaperinus . The effect of incremental CaCl 2 concentration (10, 15, 20 and 20 mmol/L) and temperature (90, 100 °C) on physical-chemical properties of insect coagula was investigated. A yield between 76 and 83 g of coagulum was obtained from 100 g of fresh larvae, decreasing with higher temperature and CaCl 2 . Protein-protein interactions and microstructure of coagula were analyzed respectively by means of protein solubility, SDS-PAGE and SEM. When higher temperature was applied, hydrophobic interactions and disulphide bonds increased due to a larger degree of protein denaturation, thereby contributing to the formation of large protein aggregates. Thus, significant increase in hardness of the coagula was observed, with specimens at 20 mmol/L CaCl 2 being more than twice harder at 100 °C than at 90 °C. Moreover, proteins homologous to actin and tropomyosin contributed to the coagulum structure by hydrophobic interactions, whereas hemolymph proteins formed disulphide bonds. Increasing concentration of CaCl 2 from 10 to 20 mmol/L, at 100 °C, displayed a smoother network that increased coagula hardness from 1200 to 2900 g respectively. Results of this study provide important information for the product development in relation to insect protein-based meat analogues.