Changes in the pectic fraction of bush butter (Dacryodes edulis (G Don) HJ Lam) fruit pulp during ripening

Abstract

CDTA-soluble polysaccharides were extracted from cell wall material (prepared as alcoholinsoluble solids) of bush butter fruit endocarp tissue at three stages of ripeness. The amount of soluble pectins remained constant but they underwent a gradual depolymerisation during ripening. The CDTA extracts were fractionated by anion exchange and the subfractions were analysed for their sugar composition and molecular weight distribution. For all degrees of ripeness the extracts were composed of three minor peaks and two major peaks. The minor peaks appeared to be composed of xyloglucan and mannan-type polymers for the ®rst peak and arabinogalactan-type polymers for the other two peaks. The two main peaks were retained on the column. The ®rst was exclusively composed of homogalacturonan polymers and the second contained principally highly branched rhamnogalacturonan polymers. During ripening, both homogalacturonan and rhamnogalacturonan populations were modi®ed. Modi®cations in the rhamnogalacturonan fraction were principally marked by the accumulation of low-molecular-weight rhamnoglacturonan polymers in the course of ripening.

Pectic polysaccharides during ripening of mango (Mangifera indica L)

“…Such a decrease in molecular weight was also shown recently for the pectic fraction of ripening bush butter fruit. 13 An earlier observation on pectic polymers of ripening mango fruit also showed molecular weight changes 16 as well as loss of sugar residues, 15 indicating extensive depolymerisation in vivo.…”

“…Pectin regulation has been extensively studied in tomato, where expression of polygalacturonase (PG) and pectin methyl esterase (PME) enzymes was individually suppressed by antisense RNA technology, to obtain a desired end result of improved texture. 3,4 Qualitative changes in pectic polysaccharides during ripening have been shown in a number of fruits, eg kiwi fruit, 5 peach, 6 melon, 7 banana, 8 persimmon, 9 bell pepper, 10 apricot, 11 olive, 12 bush butter fruit 13 and some varieties of mango. 14 -16 Nevertheless, detailed investigations showing the entire spectrum of pectic polymers present and their extent of participation in textural softening, along with the corresponding enzyme profiles, are not well documented for fruits.…”

The regular consumption of a polyphenol-rich apple does not influence endothelial function: a randomised double-blind trial in hypercholesterolemic adults

“…Cell walls were quantified as alcohol insoluble solids from the freeze-dried apple powders (Renard 2005). Starch was quantified using an enzymic-colorimetric method (Missang et al, 2001). Sugars (glucose, fructose and sucrose), and L-malic acid were determined by kit enzymatic assays (Boehringer, Mannheim, Germany and R-Biopharm AG, Darmstadt, Germany) according to manufacturer's specifications.…”

Reduction of colonic inflammation in HLA-B27 transgenic rats by feeding Marie Ménard apples, rich in polyphenols

“…Cell walls were quantified as alcohol-insoluble solids from the freeze-dried apple powders, as described elsewhere ( 16 ) . Starch was quantified by an enzymic-colorimetric method ( 17 ) as described previously ( 18 ) . Sugars (glucose, fructose and sucrose) and l -malic acid were determined by enzymic assays by Boehringer Mannheim/R-Biopharm (R-Biopharm AG, Darmstadt, Germany) according to the producer's specifications.…”