Postharvest changes in white asparagus cell wall during refrigerated storage

The postharvest changes of the white asparagus cell wall have been studied in relation to the toughening process along the length of a spear that was divided into three sections: apical, middle, and basal. Polysaccharides und erwent significant turnover during storage. Uronic acid concentration decre ased in all sections and in almost all polysaccharide fractions, while neut ral sugars increased very slightly in the apical section, decreased in the middle, and increased in the basal one. Xylose, glucose, and galactose are the main neutral sugars implicated in the turnover; xylose accumulated in t he hemicellulose fractions of the middle and basal sections, glucose decrea sed in the hemicellulose and cellulose fractions of the middle section and increased in the cellulose fraction of the basal one, and galactose disappe ared mostly from the cellulose fractions of the three sections. Lignin incr eased most in the middle section and least in the basal one. No increase wa s detected in the apical one. No important increases of wall phenolics were detected in any part of the spear. The hardening process was Limited only to the basal section.