Microwave-assisted extraction of pectin from unutilized pumpkin biomass

• The optimal condition for isolation of pumpkin pectin with microwave was obtained.
• Microwave treatment can be used to pectin modification.
• A medium Mw pectin (139 kDa) was isolated.
• Microwave heating reduced the extraction time in comparison to conventional heating.

Microwave-assisted extraction was employed to extract polysaccharides from pumpkin biomass and compared to the usual extraction by conventional heating. The effect of microwave heating time, liquid/solid (L/S) ratio and extraction temperature on the yield and molecular mass of extracted pectin from the seeded oil pumpkin biomass was investigated. Heating times ranged from 2 to 10 min, L/S ratio from 30/1 to 50/1 and temperature from 80 to 120 °C. The response surface methodology was used to optimize the effects of processing parameters to isolate pectin with medium molecular weight and with the highest yield. The retained conditions were as follows: liquid/solid ratio 50/1, microwave heating time of 10 min and a temperature of 102.2 °C. Among the studied factors, the liquid/solid ratio had the greatest influence on yield and molecular mass, respectively.