CHARACTERIZATION OF THE COMPOSITION OF TENEBRIO MOLITOR LARVA UNDER DIFFERENT OIL EXTRACTION CONDITIONS: COMPARISON OF OFFICIAL ANALYTICAL METHODOLOGIES

The Tenebrio molitor larva is a good source of proteins, lipids, carbohydrates, vitamins, and minerals. Edible insect proteins have been proposed as a functional food ingredient. Fat removal is considered a crucial processing step, as the T. molitor larva is rich in fat; this fat content can interfere with protein concentrate preparation and lead to undesirable flavors caused by lipid oxidation. The objective of this research was to characterize the T. molitor larva and different flours derived from it. Therefore, the larva and three types of flour were evaluated: T1: Tenebrio molitor larva; T2: defatted flour (cold-pressing method); T3: full-fat flour; and T4: micronized flour. The flours and the larva were subjected to proximate composition analysis (protein and ash) in accordance with AOAC methods; lipid content was evaluated using both the Bligh & Dyer and Soxhlet methods to compare the official methodologies and determine which yielded the best results. Moisture content was determined using infrared analysis and oven drying at 100 °C. The results indicate that the moisture content of the flours and the larva ranged from 2.88 to 4.37 g/100 g, while the ash content ranged from 3.06 g/100 g to 4.14 g/100 g. It was observed that the micronized flour (T4) exhibited the highest protein content (57.63 g/100 g), whereas the lowest protein levels were found in the full-fat flour (44.17 g/100 g) and the larva (T1; 45.35 g/100 g). This is attributed to the respective low and high lipid contents found in these treatments (T4: 15.34 g/100 g and T2: 18.69 g/100 g and T3: 28.58 g/100 g and T1: 27.69 g/100 g; p < 0.05). When comparing official lipid determination methods, it was found that the Soxhlet method extracted between 3.41% and 5.88% more lipid (p < 0.05) than the Bligh-Dyer method. It is concluded that given the differences found, the Soxhlet method is recommended, but infrared and the Bligh-Dyer method are simpler methodologies and need to be compared to ensure reliable results for future studies on technological applications in various food products.