Leveraging the Mass Transfer Characteristics During Frying of Texturized Meat Analogs From Manila Tamarind Seed Protein Isolate

Abstract

The present study investigated the kinetics of moisture loss and fat absorption in texturized protein-based meat analogs developed from Manila tamarind seed protein, a novel, underutilized plant-based protein source. The texturized protein samples were deep-fat fried at three distinct temperatures (150°C, 160°C, and 170°C) and various time intervals (30, 60, 90, 120, 150, and 180 s). Moisture-content, fat-content, cooking-yield, cooking-loss, textural properties, color, and in vitro protein digestibility were among the properties analyzed. The moisture-content decreased significantly (p < 0.05) with increasing frying time and temperature, while the fat-content exhibited a corresponding increase. The First-order kinetic model effectively described the moisture loss, with the highest moisture diffusivity observed at 160°C (2.67 × 10⁻⁷ m²/s). Textural analysis revealed a significant increase in hardness (from 614.9 to 1908.82 g) and a slight decrease in springiness (0.97 to 0.89) during frying. The color analysis showed a progressive decrease in lightness (L*) (from 52.46 to 34.5), redness (a*) (from 7.6 to 1.5), and yellowness (b*) (from 13 to −0.5) values, with the total color change (ΔE) increasing (0 to 21) with frying time and temperature. The in vitro protein digestibility improved significantly during frying, with the highest value (84.98%) observed at 170°C after 180 s. Microstructural analysis showed that frying created irregular pockets and fragmentation, transforming the initial uniform structure. These findings offer a novel framework for optimizing frying parameters to reduce oil uptake during deep-fat frying of plant-based meat alternatives to enhance their quality and nutritional value, thus providing a practical tool to food manufacturers.