Effect of reactive extrusion processing conditions on the production of potato-resistant starch and its use as an additive in yogurt

• Published in: International journal of biological macromolecules 2024-12, Vol.287, p.138472
• Main Authors: Rosa, Fitch-Vargas Perla, Fernando, Martínez-Bustos, Diego, Osaki-Labrada Juan, de Jesús, Zazueta-Morales José, Ariadna, Ruiz-Armenta Xochitl, Ernesto, Aguilar-Palazuelos
• Format: Article
• Language: English
• ISSN: 1879-0003

Starch has multiple uses in the food industry as a stabilizer, adhesive, gelling agent, thickener, and water retention agent. Nonetheless, native starch presents limitations that restrict its applications. Thus, starch can be chemically modified by reactive extrusion (REX) to overcome these disadvantages. Additionally, resistant starch (RS) can be obtained by REX and used as an additive to improve the nutritional quality and physicochemical properties of foods. Hence, this research aimed to determine the optimal processing conditions of REX to obtain RS with an adequate degree of substitution (DS) for use as an additive in yogurt. Potato starch was modified with sodium trimetaphosphate and sodium tripolyphosphate. The effects of extrusion temperature (ET = 90.00-160.00 °C) and moisture content (MC = 18.00-30.00 %) on the physicochemical properties (water absorption, solubility index, color, and DS) of extrusion-phosphated potato starch (EPPS) were studied. A single-screw laboratory extruder and a central composite rotatable design were employed. Natural yogurt was prepared with EPPS and conventionally phosphorylated starch, and their physicochemical and sensory properties were evaluated. EPPS showed a higher percentage of RS, which can be attributed to mechanical damage and loss of crystallinity due to REX and the formation of phosphodiester bonds and cross-linking. The optimization analysis identified the best processing conditions (107.40 °C ET and 30.00 % MC) to obtain EPPS with high RS and WAI values and a DS = 0.02. This study demonstrated that ET and MC during REX are crucial for obtaining starch with a high percentage of RS. Adding RS obtained through REX improved the yogurt's physicochemical properties and enhanced its sensory characteristics.