Development, stability and sensory acceptibility of cucumber-basil juice blend

A blend of juices from Cucumber (Cucumis sativus) and Basil (Ocimum sanctum) leaves was formulated with the help of Response Surface Methodology (RSM) and its storage stability was evaluated. Large quantities of Cucumber get spoiled in India during harvesting season. Long term preservation method of Cucumber juice is useful to prevent the spoilage of Cucumber. Addition of Basil juice increases the nutrient value of the juice blend as well as provides health benefit to the consumer. However, excess quantities of Basil juice in the product lead to unacceptable sensory qualities. Therefore, ingredients composition of the juice blend was optimized by Response Surface Methodology (RSM), a statistical design tool in which a central composite rotatable design has been used. The responses were analyzed to fit a polynomial model by least square technique. Amount of Lemon juice, Basil leaves juice and Cucumber juice, were independent variables and the overall sensory scores and acidity of the product were selected as the response. Generally the coding is done for the uniformity within the design and to avoid the bias. The coding is from -1 to +1 through ′0′ for minimum, maximum and the centre point, respectively. The actual experimental ranges of the levels of the major ingredients (independent variables) used in RSM varied from 50 to 75, 25 to 50 and 5 to 10ml for Cucumber, Basil leaves and Lemon juices, respectively. The acidity response ranged between 0.2% and 0.42%, whereas the sensory score response ranged between 6.0 and 7.9 in the experimental design. The optimized juice blend was filled in sterilized 200 ml opaque white glass bottles. After filling, bottles were sealed with air tight cap and were pasteurized in hot water at 95° C for 15 minutes, and cooled.The physico-chemical, microbiological stability and sensory characteristics of the Cucumber-Basil juice thermally processed in glass bottle were evaluated during 6 months at room temperature (28° C ± 2° C). It was observed that mean pH values ranged from 3.89 to 4.00 during storage and the mean values of total acidity ranged from 0.25 to 0.36 g /100ml. Minor changes of total soluble solids (°Brix) values was observed during storage. Loss of vitamin C and β-carotene were 74.9% and 56.9% respectively after 6 months of storage. The result revealed that the optimized Cucumber-Basil juice is acceptable and can be preserved for 6 months with good acceptability.