Physicochemical properties of cricket (Gryllus bimaculatus) gel fraction with soy protein isolate for 3D printing-based meat analogue

Abstract

Cricket (Gryllus bimaculatus) gel was fractionated and mixed with different soybean protein isolate (SPI) concentrations, and its characteristics were evaluated to determine its potential use as a meat analog. Crushed crickets were separated into the filtrate, supernatant, and pellet fractions by centrifugation and freeze-drying, and powdered and mixed with 18% SPI at different concentrations (5%–20%). The filtrate fraction had the lowest protein content and the highest fat and carbohydrate content among the nutrient fractions. Conversely, the supernatant and pellet fractions had high protein, low fat, and low carbohydrate content. SDS-PAGE detected relatively low-molecular weight proteins. Numerous muscle proteins were identified, including actin, myosin, and hemocyanin, a protein that transports oxygen in insects. Regarding the rheological characteristics of the cricket fraction, the entire fraction exhibited G'>G" in both the frequency and the temperature sweep tests, revealing a tendency for gel-like viscosity. In all cricket fractions, both G' and G" increased with increasing fraction powder concentration. When printed, supernatant fractions had no structural stability, pellet fractions had 5%–15% stability, and filtrate fractions had 5%–20% stability. The three interval thixotropy test revealed that the pellet fraction had a recovery rate of over 90% after high shear deformation. Texture profile analysis showed an increase in both hardness and chewability. After heat treatment, cohesiveness was higher than adhesiveness, indicating greater elasticity. Field-emission scanning electron microscopy results revealed that the pellet fraction was denser than the other fractions, particularly at higher concentrations. Based on the overall characteristics, 15% pellets were found to be the most appropriate fraction and concentration.