The observed growth of the global population and concern for the natural environment require the supply of inexpensive food with a low-carbon footprint. These requirements can be met, among others, by insect-derived raw materials, such as insect powders commonly referred to as flours. The aim of this study was to compare and assess the effects of four-month storage of insect powders (cricket, mealworm) and cereal flours (millet, oat, rice) under conditions similar to household storage (room temperature, partially emptied packages) on selected quality characteristics. It was assumed that, due to their different protein–fat composition and high degree of comminution, insect powders may exhibit a different dynamic of changes compared to flours in which starch is the dominant matrix. The scope of the research included the assessment of moisture content, acidity, ash content and total protein content, analysis of the amino acid profile, color parameters in the CIE L*a*b* space, changes in volatile compounds, and determination of heavy metal content (Cd, Pb, Hg, As). The obtained results enabled a comprehensive characterization of the quality stability and nutritional value of the tested raw materials after the storage period. The analyses revealed clear differences between cereal flours and insect powders, resulting from differences in chemical composition and production technology. Insect powders were characterized by a higher protein content and a more favorable amino acid profile compared to cereal flours. In addition, they exhibited lower moisture content, different color, and a distinct aroma profile, which can be attributed both to their production technology and to a higher proportion of hydrophobic components. It was shown that during storage the amino acid composition of the tested flours remained relatively stable, as did color; however, mealworm powder exhibited the lowest color stability. It was also demonstrated that cereal flours are characterized by a greater capacity for water sorption, which is related to their starch matrix, whereas insect powders undergo processes related to lipid degradation, leading to increased acidity and changes in the profile of volatile compounds. Certain safety concerns may arise from the exceeded permissible cadmium content observed in mealworm powder.
Mierzejewska et al. (Thu,) studied this question.