Effects of mealworm larva composition and selected process parameters on the physicochemical properties of extruded...

Mealworm larva (Tenebrio molitor), the most promising edible insect species with low cost and less environmental pollution, can fulfill the flavor and nutrition which are deficient in soy-based meat analog. Consumers who might have the sensitivity and reluctance to the intact form of edible insect could be offered the high-quality extruded meat analog. Therefore, this study aimed to investigate the effects of different mealworm larva contents and extrusion process parameters using twin-screw extruder on the physicochemical properties of the extruded meat analog. Mealworm larva was added to the base formulation at the rate of 0, 15, and 30%. Extrusion process parameters were varied as die temperature (140°C and 150°C) and moisture content (40% and 50%). The integrity index, texture profile analysis, and oxidation activity (TBARS) of extruded meat analog decreased with increase in mealworm larva content. However, water holding capacity, nitrogen solubility index, protein digestibility, and DPPH radical scavenging activity significantly increased (p < .05) as the mealworm content increased. Lower die temperature and higher moisture content enhanced the textural properties, but reduced nitrogen solubility index and protein digestibility. At higher die temperature, DPPH activity increased but TBARS showed the opposite result. After extrusion cooking, the total amino acid levels of extruded meat analog were 585.21 g/kg in 30% mealworm larva content that level was lower than 591.43 g/kg in raw mixture while the sulfur-containing amino acids and glutamic acid were higher than that of raw mixture. In conclusion, addition of mealworm larva could improve the nutritional value, antioxidant functionality, and taste of extruded meat analog under controlled extrusion process conditions.