Polyphenolic content, antioxidant activity and organoleptic evaluation of bitter gourd Momordica charantia L. Tea

Bitter gourd or Karela (Momordica charantia) belongs to the family cucurbitaceae. It is high in vitamins and an excellent source of iron and calcium. It is also known to cure diabetes, arthritis, rheumatism, asthma, warts, abscesses and ulcers. In the present study bitter gourd tea was developed and its sensory evaluation was conducted. The bitter gourd tea was screened for possible antioxidant activities by free radical scavenging activity (DPPH) and reducing power assay. The total phenolic content was also determined. The results of the investigations on appearance, color, flavor, taste and overall acceptability values ranged from 6.1 to 8.5. The amount of total phenolic contents found in bitter gourd tea extract was (264 ± 1.63) mg/g gallic acid equivalent (GAE). The bitter gourd tea exhibited antioxidant activity in the range from 18.35 ± 0.80 - 65.96% ± 2.50 at the concentrations (20-100µg/ml) in DPPH radical scavenging method. A concentration dependent reducing potential were exhibited by the bitter gourd tea which was compared with BHA and it was found that its antioxidant activity was higher than standard antioxidant BHA. The bitter gourd tea extract and standard BHA showed antioxidant activity with IC50 value of 72.04 ± 3.25 μg/ml and 98.75 ± 3.92 μg/ml, respectively. These results indicated that bitter gourd tea may be used as a potential source of natural antioxidant.