Malting process has minimal influence on the structure of arabinan-rich rhamnogalacturonan pectic polysaccharides from chickpea (Cicer arietinum L.) hull

The objective of the study was to determine the changes brought about by malting/germination on the pectic polysaccharides (PP's), the major components of soluble fibres present in chickpea (Cicer arietinum L.) hull. Chickpea hull PP's were extracted sequentially using ammonium oxalate (AO) and ethylenediaminetetraacetic acid (EDTA), and a comparative study was conducted in native (unprocessed, N–PP) and after subjecting to 48 h malting process (M–PP). Malting process did not show a significant change in the respective yields of AO and EDTA extracted pectic polysaccharides. The degree of esterification of N–PP–EDTA through Fourier transform infrared spectroscopy was found to be five times (~ 21%) more than N–PP–AO (~ 4%). AO isolated PP's have more complexed xylogalacturonan with relatively more galactan side chains compared to EDTA isolated PPs. Proton (¹H) nuclear magnetic resonance result further suggested the occurrence of arabinan rich rhamnogalacturonan in chickpea hull and malting process showed no significant changes in structure.