Impact of processing of red beet on betalain content and antioxidant activity

Red beet has high concentration betalains that are used as food colorants and food additives due to their health promoting properties. Redbeet is generally processed before consumption which influences the stability of betalains in turn which affects the acceptability and health properties. The objective of the study was to investigate the influence of processing techniques as microwaving, boiling, roasting and vacuuming on the red beet. The impact of processing was evaluated on the basis of belatains content and antioxidant activity of the processed samples. With spectrophotometric results betalains content were found to add up to 20% with vacuum treatment and also with microwave treatment of 900 W and 1800W for 30s up to7% and 19% respectively, however there was decrease in boiling and roasting treatments. With HPLC analyses the content of betanin seems to increase in microwave treatments with 450W and 900 W but reduced with 1800 W. In the case of antioxidant activity there was 2 to 3 fold increase in boiling, roasting and microwave treatments as compared to the control. (C) 2011 Elsevier Ltd. All rights reserved.