A value-added functional beverage was formulated utilizing unprocessed whey with excellent nutritional qualities and bland flavors; along with banana juice and the required amount of sugar. Five different formulations were prepared with varying proportions of whey, banana juice, and sugar. Sensory analysis was carried out for all five formulations. The shelf-life of the final product was observed for 30 days at room temperature (25±5°C) and refrigerated temperature (7±1ºC). A significant variation in body, color, flavor, taste, and overall acceptability were observed by varying the composition of whey and banana juice (p<0.05). The beverage was pasteurized at 82.5°C for 20 min and stored at normal (25±5◦C) and refrigerated (7±1°C) for 30 days. The effects of storage time and temperature on physicochemical (TSS, pH, acidity) and microbial (TPC, yeast & mold count) properties were evaluated. Out of five formulations, the one selected via sensory analysis had TSS of 12.4°Bx, total solids 14.21%, 0.302% acidity, pH 5.72, 5.087 % reducing sugar, 0.53% protein, 0.56% ash, 0.87% crude fiber, 184.43 mg potassium (mg/100gm) and 0.912 mg vitamin C in 100 ml. The prepared beverage was stored for 30 days under refrigerated and normal conditions, and changes in TSS, pH and acidity were observed: 12.413.3 %, 5.72-5.214, 0.32-0.43 %, and 12.4-13.8 %, 5.72-4.64, 0.32-0.68 % respectively. Overall analysis showed that the beverage prepared with 85% liquid whey and 15% banana juice could be stored for 30 days under refrigerated conditions without the addition of preservatives.
Preparation of whey
Milk was heated at a temperature of 71°C and coagulated at that temperature using a 2% citric acid solution. Complete coagulation was obtained within a minute. The whey thus obtained was strained using a muslin cloth to get a clear liquid.
·Clarified and pasteurized Milk (3% fat, 8% SNF)
·Heating up to 80◦C
·Cooling (71◦C)
·Addition of 2% citric acid (2g per kg)
·Stirring (10 minutes)
·Cooling at room temperature
·Separation of whey from the curd
·Collection of whey for the sample preparation and analysis
Preparation of banana juice
Natural banana juice was prepared without imparting any chemical/ enzymatic. Ripe bananas were washed with chlorinated water followed by manual peeling and cutting into slices of 3 – 4 mm. The banana slices along with water in the ratio of 1:2 (banana slices: water, w/w) were heated at 100℃ for 45 minutes followed by cooling, pressing, filtration, pasteurization (at 90℃ for 10 min) and again cooling at room temperature. The prepared banana juice was stored at 7±1℃ in the refrigerator for further use.
·Ripe banana
·Washing (ripe banana was washed using chlorinated water)
·Peeling (peeling of banana was done manually)
·Slicing (banana was cut into slices of 3-4 mm)
·Adding water (1:2; slices/water w/w)
·Heating (heated at 100°C for 45 minutes)
·Cooling (room temperature)
·Pressing and filtration (muslin cloth)
·Pasteurizing (at 90°C for 10 minutes)
·Cooling at room temperature
·Banana juice (Stored at 7±1 °C)
Preparation of whey beverage
The prepared whey was filtered to remove foreign material and then the filtered whey was heated to about 45°C. Banana juice and sugar were added in the calculated amount in hot whey. The prepared compositions were filled hot and crown corked in 200 ml glass bottles. The bottles were pasteurized at 72 ºC for 30 min and let cool down to room temperature (28 ºC). Sensory analysis was done for all prepared compositions, and based on sensory score best sample was selected for further chemical and microbiological analysis.
·Whey
·Filtration (to remove foreign material)
·Banana juice Heating at 45 ºC Sugar
·Bottling and crown corking (200 ml glass bottle)
·Pasteurize & cool at room temperature
·Sensory evaluation
·Selection of best formulation
·Physio-chemical analysis of beverage (pH, acidity, TSS)
Physical and chemical examination of raw whey, banana juice, and RTS
The physicochemical properties such as total soluble solids, fat content, acidity, pH, ascorbic acid, and microbiological analysis were done for raw whey, banana juice, and prepared beverage. The proximate compositions such as protein content, crude fiber, total and reducing sugar, ash content, potassium were determined.
Sensory evaluation
The laboratory-prepared samples were evaluated for color and appearance, taste, body flavor, and overall acceptability on a 9-point hedonic rating scale (AOAC, 2005).
Conclusion
Sensory evaluation of the sample showed RTS prepared from 75% whey (V/V), 15% banana juice (V/V), and 12.4 ºBx TSS showed the highest acceptability in terms of the body, color, flavor, and taste. The physio-chemical analysis of the best-selected product was found to be corresponding to a standard RTS drink. The changes during storage for 30 days were observed which showed a significant rise in TSS and acidity. From a microbial point of view, the beverage could be stored for 10 days at ambient temperature and 30 days in a refrigerator. The product proved as a nutritionally as well as organoleptically desirable beverage with agreeable taste, flavor.
Reference:
Shrestha, K. and Dahal, A., 2021. Preparation of Whey-Based Banana Beverage and its Quality Evaluation. Himalayan Journal of Science and Technology, 5(01), pp.60-66.
