Study on the Effect of Extraction Parameters and Precipitation Solvents on Pectin Yield from Lemon Peels

This study was aimed to extract pectin from lemon peel and investigates factors affecting the percentage yield of pectin. Pectin is extensively employed in a variety of food processing procedures as a gelling agent, thickening, emulsifier, and stabilizer. Chemically, it is a polysaccharide, which is a compound that all land plants' cell walls contain in varying amounts. The extraction conditions, such as extraction time, temperature, pH, MLR, and type of extraction solvents, significantly affect the yield of pectin. Pectin was extracted with acid hydrolysis techniques and the extracts were then precipitated with methanol, ethanol and acetone solvents and the effects of these factors on pectin yield were studied. Optimization of extraction parameters has been carried out with OFAT experimental design based on maximum yield. Higher yield of pectin were obtain at extraction temperature of 90°C (36.5%), extraction time of 90 min (38%), material-to-liquor ratio of 1:40 (34.75%) and pH of 2 (31%). Ethanol precipitation has given higher pectin yield than methanol and acetone. The extracted pectin was characterized for its chemical composition, solubility of dry pectin in cold and hot water and alkali, color and thermal properties. It was revealed from this study that dry pectin dissolves in hot water and alkali as well as in cold alkali. The extracted pectin shown moisture content of 13.4%, volatile compounds of 82.3%, ash content of 3.1%, fixed carbon of 14.6% and pH of 3.5 at 30°C were obtained. Hence, it can be concluded that the citrus lemon peel is a potential source of pectin for commercial purpose.