Protein fortification with mealworm (Tenebrio molitor L.) powder: effect on textural, microbiological, nutritional and sensory features of bread

In the present study, inclusion of mealworm (Tenebrio molitor L.) powder into bread doughs at 5 and 10% substitution level of soft wheat (Triticum aestivum L.) flour was tested to produce protein fortified breads. The addition of mealworm powder (MP) did not negatively affect the technological features of either doughs or breads. All the tested doughs showed the same leavening ability, whereas breads containing 5% MP showed the highest specific volume and the lowest firmness. An enrichment in protein content was observed in experimental breads where the highest values for both these parameters were recorded in breads containing 10% MP. Breads fortified with 10% MP also exhibited a significant increase in the content of free amino acids, and especially in the following essential amino acids: tyrosine, methionine, isoleucine, and leucine. By contrast, no differences in nutritional quality of lipids were seen between fortified and control breads. Results of sensory analyses revealed that protein fortification of bread with MP significantly affected texture, colour (crust), and overall liking of breads depending on the substitution level. Finally, the occurrence of spore forming bacteria in fortified breads highlighted potential spoilage and safety issues that need to be further considered. Overall, proof of concept was provided for the inclusion of MP into bread doughs started with different leavening agents (sourdough and/or baker’s yeast), at 5 or 10% substitution level of soft wheat flour. Based on the Technology Readiness Level (TRL) scale, the proposed bread making technology can be situated at level 4 (validation in laboratory environment), thus suggesting that the production of breads with MP might easily be scaled up at industrial level.