Evaluating protein quality in edible insects: A comparative analysis of house cricket, yellow mealworm, and migratory locust using DIAAS methodologies

Edible insects have garnered attention as a sustainable and nutritious food source, offering a solution to food security challenges. They are rich in protein, healthy fats, and essential nutrients like vitamins and minerals. This study investigated the protein quality of three edible insect species—Acheta domesticus (house cricket), Tenebrio molitor (yellow mealworm), and Locusta migratoria (migratory locust). The results demonstrated that all insects are rich in protein, ranging from 67.49 to 72.36 g per 100 g of dry weight, with a complete profile of essential amino acids, notably high in leucine. The total protein digestibility, reflecting the percentage of absorbed protein, ranged from 74.47% to 85.18%, indicating efficient utilization by the human body. In order to provide a more comprehensive assessment of protein quality, this study employed the digestible indispensable amino acid score (DIAAS), offering a comprehensive approach to protein quality assessment based on the human body's requirements for essential amino acids. For DIAAS, three calculation methods were used, incorporating a universal conversion factor of 6.25, an insect-specific conversion factor of 5.33, and the sum of amino acids. Using a conversion factor of 5.33 for protein calculation resulted in higher DIAAS values than using a factor of 6.25. The method based on the sum of individual amino acids in the dry matter provided the DIAAS values in the following order: 96.61 ± 8.86% for house cricket, 89.71 ± 9.22% for migratory locust, and 103.32 ± 10.11% for yellow mealworm, indicating good to excellent protein quality for all insect species. These findings highlight the importance of accurate protein content determination and its impact on assessing the nutritional quality of edible insects.