Development of a sweetener from Black plum (Vitex doniana) fruit

Abstract

The Black plum (Vitex doniana) fruit was studied in respect of the chemical composition of its edible pulp, and syrup produced by concentration of extracted juice. Organoleptic evaluation was also conducted on the developed syrup. The results show that the edible pulp of the fruit is acidic (PH 5.20), high in moisture (67.9%), sucrose (12.5%) and reducing sugar (7.3%), and fairly rich in vitamin C (28.5 mg/100g). Temperature of water used for extracting juice from the pulp correlated positively with soluble solids (r = 0.86), titratable acidity (r = 0.91) and negatively with vitamin C (r = -0.61). The syrup contained higher reducing sugars (51.7%), lower moisture (25.0%), but similar sucrose (12.9%) content compared to the pulp. The soluble solids of the extracted juice and consequently the yield of the syrup varied with water temperature. An optimum temperature of 80°C gave 20% (w/w) syrup per pulp. The syrup compares favorably with sucrose in sensory properties in model foods.