Optimization of Process Conditions (Blanching Time and Temperature) on the Beta Carotene Content of Diced Orange Flesh Sweet Potato

Abstract

Optimization of process condition (blanching and drying) on the beta-carotene content of orange fleshed sweet potato (mother delight) using response surface methodology was studied. Sweet potatoes were washed, peeled, diced, blanched, and dried at various temperature ranges. Nutritional composition of the fresh and dried samples was determined using standard methods. A three-factor central composite rotatable design (CCRD) was used to study the effects of blanching time (X1), blanching temperature (X2), and drying temperature (X3) on the beta-carotene content of the orange fresh sweet potato. Fourteen experimental combinations were produced with six replicates at the center point to generate twenty (20) runs. The sweet potato was blanched at a temperature range of 60-900C for 3-5 minutes and dried at a temperature ranging between 70-800C. the result showed that the beta-carotene content of fresh sweet potatoes was 8403µg and dried ones ranged from 4401µg to 2826µg. Sweetpotato processed for 3mins (blanching time), at 900C (blanching temperature) and 700C (drying temperature) produced the maximum beta carotene. The experimental data was fitted to a second-order polynomial equation using multiple regression analysis and the quadratic model was highly significant (p<0.05).