An innovative strategy to accurately quantify protein content in insect meals

The nitrogen-to-protein conversion factor is widely used to estimate crude protein content in edible insect meals. However, reported values vary widely across studies, raising concerns about their reliability. This study investigates using an alternative conversion factor, , applied to protein-derived nitrogen, to more accurately measure the true protein content in insect meals. Ten commercial insect meals, including five cricket-based ( Acheta domesticus , Gryllodes sigillatus ) and five mealworm-based ( Tenebrio molitor ) meals marketed in Canada were analysed. The and factors were calculated from amino acid profiles, and nitrogen distribution was determined. The non-protein and non-chitin nitrogen (N NP,NC ) was removed through protein precipitation using trichloroacetic acid and acetone. Then, protein nitrogen (N P ) was separated from chitin-bound nitrogen (N C ) through chemical deproteinisation. While values varied significantly between the commercial meals, values were consistent, averaging 5.61 for cricket meals and 5.69 for mealworm meals. Protein nitrogen constituted approximately two-thirds of the total nitrogen in the meals, while the N NP,NC fraction represented 13-24% of the total nitrogen, and varied significantly, even among products from the same species. An additional 8-17% of the total nitrogen remained uncharacterised. Using the conventional value of 6.25 resulted in a 35-46% overestimation of protein content compared with using applied to N P , while the commonly accepted insect meal-specific value of 4.76 still led to a 15-29% overestimation. These findings support using factors (5.61 for orthopterans, 5.69 for coleopterans) applied to protein-derived nitrogen as a more accurate approach to quantify proteins in insect-based ingredients.

• Publication year

  2025

• Venue

  Journal of Insects as Food and Feed

• Publication date

  2025-10-28

• Fields of study

  Not labeled

• Identifiers
  DOI 10.1163/23524588-bja10321
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar

• No claims are published for this paper.

• No concepts are published for this paper.

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