Method for extraction of pectin from apple pomace-waste generated from apple juice processing industries for
commercial adoption was optimized. Fresh pomace yielded 13.3% pectin on dry weight basis (dwb). Blanching of pomace
(boiling at 95oC for 5 minutes followed by cooling) and drying (at 50±2oC) was found to be a necessary pretreatment before
pectin extraction. Among different methods of pectin extraction and precipitation, extraction of apple pomace by using
0.05N HCl at 95oC for one hour followed by precipitation in 95% ethanol was found optimum with pectin yield of 10.5% on
dry weight basis. The resultant pectin was characterized by 59.1% anhydrogalacturonic acid content, 71.2% degree of
esterification (DE) and 110 jelly grade. Water and Ammonium Oxalate-oxalic acid extractions on the other hand yielded
very low 3.4 and 8.0% pectin, respectively. Sequential combination extractions, viz. water and acid or water and ammonium
oxalate-oxalic acid though yielded slightly higher amount of pectin yet the addition of a unit operation along with
comparatively low increase in pectin yield was found to limit their use for pectin extraction. Among precipitation methods,
precipitation of extract in 95% ethanol resulted in higher pectin yield with comparable quality of the pectin obtained by
using aluminium chloride precipitation. The cost of production of pectin calculated on the basis of input used and after
adding labour and processing charges worked out to be Rs. 808.30 per kg. The standardized method of pectin extraction and
precipitation can be used commercially by the processing industries for utilization of apple pomace.
Keywords: Apple pomace, Blanching, Pectin extraction, Waste utilization.
IPC code; Int. cl. (2014.01)−A61K 36/00