Effect of Mealworm Powder Substitution on the Properties of High-Gluten Wheat Dough and Bread Based on Different Baking Methods

Abstract

Mealworms (Tenebrio molitor) are protein-rich edible insects that have been regarded as novel food ingredients. In this study, high-gluten wheat flour was formulated with dried mealworm powder at various levels (0%, 5%, 10%, 15%, and 20%) to study its influence on the pasting, farinograph, and extensograph properties and microstructure of the dough. A subsequent decrease in the pasting parameters was observed due to starch dilution. The water absorption, dough development time, and dough stability time decreased gradually from 71.9% to 68.67%, 13.6 min to 10.43 min, and 14.1 min to 5.33 min, respectively, with the increase in the substitution of mealworm powder from 0% to 20%. The farinograph characteristics corresponded to a weak gluten network formed through the dilution of gluten by the replacement of wheat flour with a non-gluten ingredient. The stretch ratio of the high-gluten dough increased gradually from 4.37 (M0) to 6.33 (M15). The increased stretching resistance and extensibility of the dough with 5% and 10% mealworm powder indicated that mealworm powder can act as a plasticizer in the gluten network, which might contribute to the decreased strength and increased elasticity and flexibility of the dough network. The bread made with three different baking methods showed similar increases in specific volume and decreased hardness up to the 10% substitution level, owing to the increased elasticity and flexibility of the dough. The GB/T 35869-2018 Rapid-baking method, GB/T 14611-2008 Straight dough method, and automatic bread maker method exhibited the highest specific volumes of 3.70 mL/g, 3.79 mL/g, and 4.14 mL/g when the wheat flour was substituted with 10% mealworm powder. However, 15% and 20% mealworm powder substitution markedly reduced the bread quality owing to the dilution effect and mealworm powder phase separation. These results provide a perspective on the relationship between the rheological properties of mealworm powder-substituted high-gluten dough and application suggestions for insect food development in the food industry.

Characterization of wheat dough and Chinese steamed bread using mealworm powder formulated with medium‐gluten and whole wheat flour

“…The specific volume of medium‐gluten wheat steamed bread and whole wheat steamed bread significantly decreased, indicating that high concentration (>15%) of mealworm powder inhibited the formation of a better gluten network structure. In our previous study, 31 the specific volume of bread with increased mealworm powder concentration exhibited a similar trend. The specific volume of whole wheat steamed bread was lower than that of medium‐gluten wheat steamed bread, indicating that whole wheat flour has a detrimental effect on the strength and gas retention ability of steamed bread dough.…”

“…The pasting temperature of medium‐gluten wheat flour did not exhibit any significant changes after mealworm powder addition but that of whole wheat flour significantly increased upon addition of 20% (w/w) mealworm powder. This may be because the high dietary fiber content of whole wheat flour alters the solid heat transfer rate, leading to an increase in the pasting temperature 30,31 …”

“…The dough development time and stability time of whole wheat dough significantly decreased with an increase in the concentration of mealworm powder, which was similar to the effect observed on high‐gluten flour. This is because the interaction between mealworm powder and gluten prevents complete hydration of proteins, thus hindering the correct formation of the gluten matrix during dough mixing 31 . Fang et al 34 .…”

“…This is because the interaction between mealworm powder and gluten prevents complete hydration of proteins, thus hindering the correct formation of the gluten matrix during dough mixing. 31 Fang et al 34 reported that the addition of isomaltodextrin to high-gluten flour significantly reduced the dough development time and stability time, which may be because of the inability of overdiluted gluten to form a strong and elastic network structure. This hypothesis is supported by the study by Roncolini et al, 15 who reported that mealworm powder negatively affected the dough development time and stability time of high-gluten dough.…”

“…This may be because the high dietary fiber content of whole wheat flour alters the solid heat transfer rate, leading to an increase in the pasting temperature. 30,31…”