Effects of pH, Temperatures and Metal Ions on the Degradation of Banana Pectin Polysaccharides by Polygalcturonase

Abstract:

Water-soluble pectin (WSP) and acid-soluble pectin (ASP) polysaccharides were isolated from pulp of banana at different mature stages, and then the effects of pH, temperatures and metal ions on the degradation of WSP and ASP caused by endopolygalcturonase (endo-PG) were studied. The results showed that the optimum pH of endo-PG was from 3.7 to 4.6. At the same pH, the degradation of WSP by endo-PG increased with banana maturity, but that of ASP decreased. The degradation of WSP and ASP by endo-PG increased with the temperature from 20℃ to 40℃. Moreover, Ca2+, Cu2+, Mg2+and Fe3+ inhibited significantly the degradation of WSP and ASP, but Fe2+and Mn2+ enhanced significantly. It was suggested that pH, temperatures and metal ions could cooperate the degradation of pectin polysaccharides of banana.

Key words:Endopolygalcturonase (endo-PG); Banana; Pectin; Polysaccharide; Degradation