Air-frying of meat analog based parfried frozen batter coated foods

Abstract

Air-frying (AF) is a novel method of producing low-fat containing fried foods using hot-air. This study investigated the effects of AF parameters on mass-transfer, texture, surface microstructure and color changes during air frying of meat-analog based batter coated parfried frozen products, and mathematically modeled their kinetics. Wheat and rice flour-based batters were used to coat a meat-analog model. Coated products were partially-fried at 180 °C for 1 min in canola oil and subsequently frozen at −18 °C for 7 days. Frozen-products were fried for different time (0, 5, 10, 15, 20 min) by hot-air of different temperature (160, 170, 180, 190 °C). Mass-transfer, texture and color development during AF of parfried-frozen coated products were dependent on both AF parameter and batter-formulations. At varied temperature, moisture content of frozen-products declined with AF time. Non-linear regression analysis outcome (R2, sum square error) showed that Newton, Page, modified Page, and Henderson & Pabis model satisfactorily predicted moisture-loss of parfried-frozen products. Zero-order kinetic model satisfactorily characterized the changes in textural (hardness, brittleness, crispiness) and color (L, a*,b*, ΔE) traits. Rate-constant (min−1) of moisture, texture and color changes were positively correlated with AF temperature. Arrhenius model sufficiently characterized the temperature-dependency of rate constants. Higher moisture diffusivity (Deff, m2/min) and rate constant (k, min−1) of textural changes were estimated for rice-flour based batter coated products, whereas higher rate of total color change (ΔE) and activation energy (Ea, kJ/mol) were estimated for wheat-flour based batter coated products. Surface microstructure (openings, roughness) of air-fried products were impacted by batter-formulation and parameters of AF. Overall, batter formulations and AF parameters are the key to customize both macro and micro quality attributes of meat-analog based batter coated product.