Studies on cell wall polysachharides with special reference to pectin substances and their antioxidant activity during different stages of ripening in Prunus armeniaca

Abstract

newline This study was carried out to see the changes in the cell wall polysaccharides in Prunus armeniaca during different stages of fruit ripening. Also, the antioxidant activity during ripening was determined. The fruits during different stages of fruit ripening were collected and processed to obtain acetone insoluble solids named as AIS and the yield and sugar composition of AIS was determined. newline The AIS of all the stages of fruit ripening in Prunus armeniaca was subjected to sequential extraction on the basis of the solubility of pectic fraction into four fractions based namely chelator soluble pectic fraction, carbonate soluble pectic fraction, alkali soluble fraction and cellulosic residue fraction. Changes in sugar composition of all the four fractions of AIS were seen. newline The increase in the activity of Pectin Esterase, Beta galactosidase and Polygalcturonase was observed which is due to the increase in soluble polyuronides during ripening. In chelator soluble pectic fraction it was observed that the apparent viscosity increased from immature green to mature green stage and then consecutively decreased in pre ripe and ripe stages. In the carbonate soluble pectic fraction the pattern of apparent viscosity during ripening was same as chelator soluble soluble fraction. Similarly, in the carbonate soluble pectic fraction the weight average molecular weight was increased from immature green to mature green and then showed a decrease in pre ripe to ripe Stage. The percent moisture content per g and the percent ash content per g were found to be increased during ripening. The Soluble dietary fibre mg per 100g was decreased during ripening.The Insoluble dietary Fibre mg per100g was increased during ripening. The method for the extraction of pectin was optimised. All the stages of fruit ripening were assessed for antioxidant activity, and their antioxidant activity was expressed as mM AAE per 100g of fruit material. newline newline