Effects of microwave pretreatment on the physicochemical properties of enzyme-infused carrots

Abstract

We investigated the possibility of textural modifications in older individuals with dysphagia by administering microwave treatment to enzyme-infused carrots. Microwave pretreatment conditions, including processing time and power levels (120, 400, 640, and 800 W), were examined for their impact on texture softening efficiency, microstructure, β-carotene content, and color. Regression analysis confirmed that processing time substantially influenced carrot hardness, with higher the softening rate increasing as microwave power levels rose from 120 to 800 W. The log-linear model demonstrated a strong correlation coefficients (R² = 0.9732–0.9407) across different power levels, confirming its reliability in achieving the target texture. The derived times, based on a log-linear model, successfully reached a target hardness of 5.0 × 10⁴ N/m² (KS level 2), with times of 371 s at 120 W, 198 s at 400 W, 72 s at 640 W, and 61 s at 800 W. The samples pretreated for the derived times corresponding to 120, 400, 640, and 800 W exhibited varying porosity levels, influencing the quality of enzyme-infused carrots. With increasing microwave power, the microwave-pretreated carrots showed improved color (more yellow and red) and preservation of β-carotene, potentially linked to shorter processing times. These results suggest that microwave pretreatment followed by enzyme infusion is an efficient approach to softening carrot texture without compromising its quality, and the log-linear model offers a predictive framework for modifying food textures in dysphagia management.