Characteristics of Oils Extracted from Yellow Mealworm (Tenebrio molitor L.) Dried with the Infrared-Convective Method

Edible insects are a nutritionally attractive food product, also due to their high fat content and high levels of unsaturated fatty acids. In this work, the effect of pulsed electric field (PEF) pretreatment and infrared-convective (IR-CD) drying on the oil properties extracted from yellow mealworm (Tenebrio molitor L.) larvae was investigated. The oil from raw and dried insects was extracted via the Soxhlet method for yield determination and via the Folch method for quality analysis. The acid value (AV) and peroxide value (PV) via the titration method, fatty acid composition and its distribution in triacylglycerol (TAG) molecules via the gas chromatography method, calculation of nutritional value indices, oxidative stability via pressure differential scanning calorimetry (PDSC) method, and antioxidant activity of methanol extracts were examined. The results show that PEF may enhance the oil extraction yield from dried insects by up to 29.2%. The PEF treatment and drying method made insect oils more valuable by lowering their acid and peroxide values, increasing the MUFA content, and improving oxidative stability. Nonetheless, the nutritional properties of oils deteriorated. Our study demonstrated that oils extracted from dried yellow mealworm could be used as an ingredient in other food products to improve their nutritional value. However, more research in this area is needed to assess the impact on quality properties.