Physicochemical, Rheological, and Structural Changes in Corn Tortilla Chips Partially Substituted by Soy and Opuntia Flour Dehydrated by Infrared Radiation

Abstract

The development of a tortilla-type product based on corn flour and the partial substitution of Opuntia flour (OF) and soy flour (SF) emerged from the need and demand of the snack sector for a product of better nutritional quality. This study evaluated the effect of substitution of OF and SF in the tortilla–chip process and the effect of infrared dehydration on the process. Nixtamalized corn flour (NFC) was replaced by 5% and 10% of OF, 4%, 5%, and 6% of defatted SF, and a mix of 5% and 4% of OF and defatted SF, respectively. High protein content is observed in raw SF (52%) and fiber content in raw OF (43%). Pasting properties and the water solubility index (WSI) were diminished by the substitutions. Infrared dehydration considerably affects water and moisture content and reduces the oil absorption rate. The color analysis revealed that increasing OF substitution decreased luminosity (L∗) and intensified greenish tones, while defatted SF maintained color stability. The highest total color difference (ΔE) was observed in formulations with 10% OF, especially after frying, indicating significant pigment interactions and thermal effects. Plasticity, elasticity, and the fracture force of the material were influenced by OF and SF. In texture properties, significant differences were observed; for OF, the greater the substitution, the less force the piece required for fracture; on the other hand, the soybean demonstrated a considerable increase in strength for the level of 1% (p < 0.001). In conclusion, it was found that SF and OF are viable for replacing NCF in combined percentages of no more than 10%, in that it can be processed at an industrial level without modifying the representative characteristics of the product and improving nutritional quality by increasing the fiber and protein content.