Study on Osmotic Dehydration of Kale (Brassica oleracea) and its Application in Beverage Development

ABSTRACT Osmotic dehydration is a technique that retains the nutritional attributes of the perishable food products especially vegetables and enhances their shelf life. This phenomenon is eco- friendly and is used to remove the water content leading to increased storage capacity. Kale is a leafy green vegetable that has gained attention of the scientific community due to its high content of bioactive compounds and health-promoting phytochemicals. The present study was undertaken to investigate the effect of two osmotic agents; NaCl and Sucrose in 1:1 ratio in combination with dehydration on the proximate and mineral composition of selected vegetable. Further the study focussed on formulation and sensory appraisal of juices prepared from kale. The proximate composition (Moisture, Ash, Protein, Fat, Fibre and Carbohydrates) was analysed by standard procedures given by AOAC and minerals were determined by AAS. The findings showed osmotic agents with 40° Brix significantly increased Ash (3.73 ± 0.05), Fat (0.7 ± 0.3) and Fibre (9.28 ± 0.02) while 70° Brix significantly increased Protein (2.28 ± 0.12) and Carbohydrate (9.73 ± 0.17) content. While mineral content determination showed osmotic agents with 70° Brix significantly increased all minerals except Iodine. Furthermore, kale juice with 60% concentration had significantly higher scores in sensory evaluation as compared to other variants. Thus, the current study recommends application of osmotic dehydration technique that results in reduced moisture content, leading to longer shelf life and enhancing the quality attributes indicating its multirole consumption, moreover the study also suggests that kale is a healthy choice for consumption that can be included into human diet.