FT-IR and FT-Raman characterization of non-cellulosic polysaccharides fractions isolated from plant cell wall

• Spectral data analysis used for characterization of cell wall polysaccharides changes.
• The drop down of esterification degree of pectic polysaccharides during maturation.
• Pectins changes from long to short chains of polygalacturonic acid in WSP fraction.
• ISP contained certain amounts of RGI and different amount of pectic galactan.
• DASP fraction molecules length were shortened during tomato ripening.

The purpose of this work was to reveal the structural changes of cell wall polysaccharides’ fractions during tomato fruit development by analysis of spectral data. Mature green and red ripe tomato fruit were taken into consideration. The FT-IR spectra of water soluble pectin (WSP), imidazole soluble pectin (ISP) and diluted alkali soluble pectin (DASP) contained bands typical for pectins. Whereas for KOH fraction spectra bands typical for hemicelluloses were present. The FT-IR spectra showed the drop down of esterification degree of WSP and ISP polysaccharides during maturation. The changes in polysaccharides structure revealed by spectra were the most visible in the case of pectic polysaccharides. The WSP and DASP fraction pectins molecules length were shortened during tomato maturation and ripening. Whereas the ISP fraction spectra analysis showed that this fraction contained rhamnogalacturonan I, but also for red ripe was rich in pectic galactan comparing with ISP fraction from mature green.