Improving the Beta-carotene Content of Carrots through Process Optimization

Abstract

Response surface methodology was used to optimize the process conditions (blanching and drying) on the beta-carotene content of carrots. Carrots were washed, peeled, diced, blanched and dried at various temperature ranges. The 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 carrot. Fourteen experimental combinations were produced with six replicates at the centre point to generate twenty (20) runs. The carrot was blanched at a temperature range of 60-800C for 2-5 minutes and dried at a temperature ranging between 50-700C. The result obtained indicated that the beta-carotene content of fresh carrot was 5738 µg. The processed carrots ranged from 2478 µg to 1060 µg. It was observed that carrot processed for 2 mins (blanching time), at 800C (blanching temperature) and 500C (dryingtemperature) produced the highest 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).