Effects of operating conditions during hollow fiber ultrafiltration of bitter gourd (Mormordica charantia) extract and analysis of nutritional qualities in subsequent storage study

Abstract

Bitter gourd extract was clarified by cross flow ultrafiltration using a hollow fiber module under total recycle mode using polysulfone based membrane. The 70 kDa membrane was found to be the most suitable among the 10-, 44-, 70-, and 120 kDa molecular weight cut-off membranes. Variations of various resistances, viz. membrane hydraulic resistance, pore blocking resistance, and fouling layer resistance with operating conditions were examined. Effect of transmembrane pressure and cross flow rate on flux and quality parameters were examined and based on these results 138 kPa transmembrane pressure and 30 L/hr cross flow rate were found suitable operating conditions for processing of extract. Storage study revealed that the ultrafiltered extract could be successfully stored for 20 weeks without any additive, preservative and flavoring agent, maintaining its natural taste, aroma, nutrition, flavor, color, smell, and other nutritional qualities at par to fresh extract.