Optimization of microwave assisted acid extraction and characterization of pectin from saffron flower waste (Crocus sativus L.)

Saffron flower waste is a new source of pectin and response surface methodology (RSM) was used to optimize the microwave-assisted acid extraction process. The optimal extraction conditions of pectin obtained from saffron flower waste were in microwave power of 700 W, irradiation time of 2.43 min, and pH of 1.5. The physicochemical and functional properties of pectin was evaluated and the results demonstrated that pectin extracted under optimal conditions was low methoxyl with emulsifying activity of 67.97%, surface activity of 36.89 mN/m and 33.24 mN/m at 0.10 and 0.50 % w/v, total phenolic content (TPC) of 2.86 mg EGA/g pectin and degree of esterification (DE) of 40.99%. In addition, the FT-IR and 1H-NMR spectra were used to identify the functional groups existing in the structure of extracted pectin.