Pectin from Sweet Lime (Mosambi) Processing Waste: Process Optimization, Characterization of Physico-Chemical and Functional Properties

Peel and pomace are the major processing waste of sweet lime juice industry which can be the major source of pectin which finds prime commercial use in food industries. In the present study, pectin was extracted from the peel and pomace of sweet lime (mosambi) using acidified water. Optimization of process parameters was done using Box-Behnken design of response surface methodology using 3 independent variables viz. time (30-90 min), temperature (30-90°C) and pH (1-2) and four responses viz yield, methoxyl content, anhydrouronic acid content (AUA) and degree of esterification (DE). Yield of pectin from both peel and pomace was significantly affected by pH of extraction medium. Optimized parameters of pectin extraction from peel and pomace were 78.64 and 56.87°C temperature, 59.12 and 68.45 minutes time and 1.32 and 1.58 pH, respectively, which gave 20.87 and 13.5% yield, 8.27 and 7.67% methoxyl content, 67.47 and 61.46 % AUA and 74 and 71 % DE, respectively. Water holding capacity (WHC) and oil holding capacity (OHC) were higher in peel than pomace. Our results indicated that mosambi peel can be utilized for extraction of pectin at commercial scale.