Calcium chloride impregnation of potato slices using ultrasound to reduce oil absorption during frying

Abstract

Abstract Ultrasound was used to deliver Ca +2 ions to specific parts of the potato tissue (lamella‐media in inner cells) to stabilize the cellular material during deep‐fat frying, thus minimizing oil absorption. Potato slices were soaked in a solution of CaCl 2 (1, 5, 10, 20, and 50 × 10 3 ppm) at different times (5, 10, and 30 min) using ultrasound (47 kHz, 240 W) before frying (165°C, 85 s). At a CaCl 2 concentration of 50 × 10 3 ppm and 30 min of sonication, the samples had a reduction of 43% in oil content when compared to the control (fried chip without pretreatment). Response surface methodology studies predicted an oil content of 0.21 kg oil/kg dry matter (DM) for nonsonicated chips soaked in 50 × 10 3 ppm solution of CaCl 2 for 16.5 min, and 0.16 kg oil/kg DM for sonicated samples impregnated for 23 min. Higher CaCl 2 concentrations yielded darker samples, lower porosity, and higher degree of shrinkage for the sonicated and nonsonicated samples. The sonicated treatment scored the highest values for texture, flavor, and overall quality from a sensory consumer test. Micrographic images of potato slices revealed that the cellular structure was stabilized when the samples were treated with solutions of 20–50 × 10 3 ppm of CaCl 2 using sonication for 30 min. Practical Applications Sonication with CaCl 2 impregnation of potato tissue effectively reduces oil absorption in potato chips during deep‐fat frying by 43% when compared to untreated controls. By physically and/or chemically altering the structure of raw materials, achieving the desired final product quality attributes—color, texture, odor, and flavor—should be more tunable by the manufacturing process. This technology will bring versatility to the use of raw materials into the development of new products without the need of altering the already established conventional unit operations and equipment. Therefore, this combined technology should attract a great deal of interest not only from the scientific community, but also from the food and snacks industry.