Evaluation of the partial substitution with cricket flour (Acheta domesticus) on the physicochemical, protein and starch digestibility characteristics of corn tortillas

Abstract

Edible insects have gained attention as an alternative and sustainable source of protein. One of the challenges is making it attractive for consumers; for this reason, it is often mixed with other ingredients. This thesis research aimed to evaluate how the addition of cricket flour (Acheta domesticus) chemical, nutritional, and digestibility characteristics of corn tortillas. Nixtamalized corn flour (NCF) tortillas with 5%, 7.5%, and 10% A. domesticus flour (AD) were formulated, elaborated, and characterized. Addition of AD caused significant visual differences in samples in terms of color and particle content. Addition of AD increased protein and lipid content while decreasing carbohydrate content. AD addition impacted carbohydrate composition by increasing the fiber portion and reducing the starch content. Furthermore, starch composition was also affected, AD increased RS (resistant starch) content. The in vitro starch digestibility was affected with the substitution of AD, which was strongly negatively correlated (R=-0.99) with the substitution percentage of AD. The presence of amylose-lipid complex, a type of resistant starch, was observed in differential scanning calorimetry, with a second transition at temperatures above 100oC. Principal component analysis (PCA) showed an important cluster between lipid content and resistant starch content which also supports DSC findings. The lowest glycemic index (GI) in vitro was observed in tortillas substituted at 10% with AD. In vivo, results differed, and the lowest GI value was observed in the samples with 7.5% of AD.