Abstract

In consideration of the medicinal and health benefit of picolinic acid (PA), this research work compared its effectiveness as a preservative with potassium sorbate and sodium benzoate in ginger juice. Concentration of 0.07, 0.067 and 0.073% of PA, potassium sorbate and sodium benzoate, respectively, were added to ginger juice, packed in polyethylene terephthalate (PET) bottles and stored for 12 weeks at ambient condition. Chemical properties (total soluble solids, total phenolic content, total flavonoids, titratable acidity and ascorbic acid), pH as well as microbiological properties (total viable count and total mould count) of the juice were observed on a fourth night basis. Total phenolic content and total flavonoids were best retained in the sample with PA than others. Higher values for pH and total soluble solids were recorded in the sample preserved with potassium sorbate and sodium benzoate. Proliferation of microbial growth was best controlled by sodium benzoate. PA could be used in preference to the other two preservatives due to its ability to preserve bioactive substances as well as its health and medicinal advantages over others.

Key words: Ginger juice, preservative, picolinic acid, potassium sorbate, sodium benzoate.