Evaluation of strawberry juice preserved with chemical preservatives at refrigeration temperature

Abstract

This study was carried out to investigate the effect of chemical preservatives on strawberry juice. The samples were; pasteurized strawberry juice (T0), pasteurized strawberry juice with 20% sucrose (T1), pasteurized juice with 0.1% sodium benzoate (T0), pasteurized juice with 20% sucrose and 0.1% sodium benzoate (T3), pasteurized juice with 0.1% potassium sorbate (T4) pasteurized juice with 2% sucrose and 0.1% potassium sorbate (T5) pasteurized juice with 0.05% sodium benzoate and 0.05% potassium sorbate (T6) pasteurized juice with 20% sucrose, 0.05% sodium benzoate and 0.05% potassium sorbate (T7) pasteurized juice with 0.1% sodium benzoate and 0.1% potassium sorbate (T8) and pasteurized juice with 20% sucrose, 0.1% potassium sorbate and 0.1% sodium benzoate (T9). The samples were stored at 4 - 15°C for three months. T0and T1 were rejected soon due to spoilage. Minimum ascorbic acid content was reduced in T9 (9.8%), while maximum in T2 (26%). Acidity increased from 1.39 to 2.38% with maximum in T1 and T9. pH decreased from 3.29 to 2.22. Reducing sucrose increased from 15.7 to 17.8 and non-reducing sucrose decreased from 11.6 to 8.3. The total soluble solids (TSS) increased from 16.5 to 17.4° brix with maximum in T0 (60%) and minimum in T6 (5.6). Treatments T9, T7 T5 and T3 were found most acceptable in maintaining the sensory characteristics compared to others during storage. Minimum microbial load were observed in T9 and maximum in T0 and T1 (uncountable). Among all the treatments T9 were most effective in maintaining the sensory and nutritional quality during storage.   Key words: Strawberry juice, pasteurization, benzoate, benzoate, citric acid, sucrose.