Isolation and use of bitter gourd polysaccharide in formulating dietetic soft drinks

Abstract

This study was conducted to determine the polysaccharide components of bitter gourd and dietetic soft drinks developed using crude bitter gourd polysaccharides. Both water insoluble materials (WIMs) and alcohol insoluble materials (AIMs) were prepared from bitter gourd flesh and AIMs were fractionated for pectin, hemicelluloses and cellulose. Major parts of bitter gourd flesh were found cellulose (27.5%), followed by hemicelluloses (13%) and the lowest parts were pectin (12%). Hot water extraction method was used to isolate crude bitter gourd polysaccharides and heating for 60 min at 90°C, resulting in the highest solid release (1.73%). In case of formulating dietetic soft drinks, optimum condition for hot water extraction as well as the best acid-sweetener ratio was used to formulate the dietetic soft drinks. Three samples were prepared using crude polysaccharides isolated by heating of 0, 5, 7.5 and 10% bitter gourd slices at optimum condition. Significant differences were observed among the samples in terms of color, flavor, taste and overall acceptability. Samples prepared using 7.5% bitter gourd slices into optimized solution secured the highest scores (60%). Key words: Bitter gourd, water extraction, polysaccharides, dietetic drinks, high sweeteners.