THE POTENTIALS OF GINGER AND SELECTED CHEMICALS AS PRESERVATIVES ON THE SHELF LIFE OF GROUND SEEDS OF MELON (Colocynthis citrullus L.)

Abstract

The research examined the potentials of ginger and selected chemicals as preservatives on the shelf life of ground seeds of melon (Colocynthis citrullus L.). Due to increased search for natural antimicrobials and preservatives, the preservative effect of ginger was compared with that of sodium chloride, sorbic acid and calcium propionate in extending the shelf life of ground melon seed (GMS) at concentrations of 0.1%, 1%, 3% and 5%. The treated and untreated samples were stored at room temperature for 12 weeks. The bacterial counts during the 12 week storage ranged from 0.2×105 to 1.69×106 cfu/ml while the control recorded the highest microbial counts. The sample treated with 5% ginger exhibited the highest preservative action at 5weeks while, the samples treated with calcium propionate at all concentrations exhibited the least preservative action. A marginal decrease in pH was observed for all samples except for those treated with sorbic acid. Phytochemicals isolated from ginger include tannins, glycosides, saponins, flavonoids, coumarins, phenols and terpenoids which might be responsible for its antimicrobial properties. In conclusion, 5% ginger gave the best preservative action followed by 5% sorbic acid and 5% Sodium chloride while all concentrations of calcium propionate showed the least preservative action.