13. Study on storage stability of grapes juice preserved with sodium benzoate, potassium sorbate and potassium metabisulphite

Abstract

This study was carried out to find the effect of potassium metabisulphite, potassium sorbate and sodium benzoate on the preservation and overall quality of grapes juice. Total seven samples were made with this juice which were named as J₀, J₁, J₂, J₃, J₄, J₅, J₆. They were kept in plastic bottles and stored at room temperature. All samples were analyzed at fifteen days interval physiochemically (pH, total soluble solids, % acidity, ascorbic acid, reducing and non-reducing sugar) and organoleptically (color, flavor, taste and overall acceptability) for a total period of 90 days. Results obtained from statistical analysis (α  showed that storage interval and preservation had significant effect on physiochemical and organoleptic characteristics. Total soluble solids increased maximum in J₀ (7.46%) and minimum in J₄ (2.79%). Ascorbic acid reduced maximum in J₀ (70.40%) and minimum in J₂ (29.14%). pH reduced maximum in J₀ (17.23%) and minimum in J₄ (4.06%). Acidity increased maximum in J₀ (41.00%) and minimum in J₄ (11.18%). Reducing sugars increased maximum in J₀ (69.51%) and minimum in J₄ (8.81%). Non-reducing sugars decreased maximum in J₄ (83.33 %) and minimum in J₂ (36.22 %). Color score decreased maximum for J₁ (53.30%) and minimum for J₄ (8.00%). Flavor score decreased maximum for J₂ (50 %) and minimum for J₆ (12.43%). Taste score decreased maximum for J₂ (62.66%) and minimum for J₄ (8.00%). Overall acceptability score decreased   maximum for J₂ (54.35%) and minimum for J₄ (10.26%). J₄ [(grapesjuice + potassium metabisulphite (0.05%) + potassium sorbate(0.05%)] remained very acceptable during storage while J₀ [grapes juice + no preservative] was found very bad. Future study is recommonded on microflora assesment, micronutrients  assesment, flavonoids and polyphenols extraction which can be added to other food products to prevent cancer in population.

Keywords: Acidity; Ascorbic acid; Organoleptics; pH; Sodium benzoate; Total soluble solids

http://dx.doi.org/10.19045/bspab.2018.70013