Pectin from pods of Riang (Parkia timoriana (DC.) Merr.): chemical properties and jelly products

Abstract

      Pods of Riang (Parkia timoriana (DC.) Merr.) yielded 10.82% pulp. The pulp contained 27.86% dietary fiber, 5.49% ash, 5.04% protein and 0.77% fat (dry weight basis). Pulp of Riang pods was qualified as low methoxyl pectin with 4.13% methoxyl content. The equivalent weight of pectin was between 5300-5900 forming a good gel  in lime water with or without the addition of sugar. However, the mixture did not form a gel when it was boiled. The most accepted Riang jelly by panelists was formulated with pulp, water, sugar, and lime water with the ratio of 1.5: 35: 12: 30, respectively. The jelly with the addition of 0.15% citric acid resulted in precipitation of Riang pulp and the mixture did not form a gel when the citric acid was added ? 0.20%. The acceptance of Riang jelly increased significantly (p<0.05) when the color, flavor and citric acid were added. The jelly product with the addition of 0.10% citric acid and 0.03% strawberry flavor was the most accepted.
      The colored and flavored strawberry jelly kept for 12 weeks at room temperature showed that the gel strength decreased significantly (p<0.05) when the duration of storage increased (the strength of the gel was in the range from 0.045 to 0.063 N). The total microorganisms were found < 1?104 CFU/g, yeasts and moulds < 100 CFU/g and E. coli < 3 MPN/g. The colored and flavored strawberry Riang jelly product was the moderate and much liking accepted by a hundred general consumers.