Modeling of peroxidase inactivation and temperature profile during infrared blanching of red bell pepper

Abstract

Infrared (IR) blanching resulted in moisture loss (~1.6%), whereas fat, crude fiber, protein and carbohydrate contents were not affected. Retention of ascorbic acid (94.3%) and β-carotene (108.4%) was found to be high after IR blanching. Inactivation of peroxidase (POD) and temperature profile in red bell pepper was predicted by employing different models. Fractional conversion model and multiple regression analysis were used to predict the POD inactivation at different temperatures (130, 150 and 170C). The time–temperature–distance relationship and multiple regression analysis were used to predict the temperature at different points (0.5, 2.5 and 4.5 mm from top) of red bell pepper subjected to IR blanching at 150C. The multiple regression analysis was found to fit well (R² = 0.996–0.997) with the experimental values for predicting POD inactivation than fractional conversion model (R² = 0.868–0.943). The temperature profile during blanching of red bell pepper was predicted well by using time–temperature–distance relationship (R² = 0.996–0.999) and multiple regression analysis (R² = 0.979–0.989).