Development of a UV coupled indigenous hydrophilized polyamide membrane system for enhanced shelf life of mature coconut water

The demand for mature coconut water is growing tremendously in beverage industries due to its high salubrious value and potential healing properties. Many coconut processing industries that manufacture products such as coconut oil, coconut milk, and desiccated coconut generate a massive volume of unutilized mature coconut water. Thus, the discharged liquid waste of valuable food products causes severe environmental pollution. Therefore, there is a need to develop a strategy to treat the unused liquid discharge that can improve shelf-life, natural freshness, flavor, aroma, and recovery of value-added products. In the present investigation, mature coconut water (CW) was concentrated by a UV coupled hydrophilized polyamide (HPA) reverse osmosis (RO) membrane. Experiments were conducted by varying functional parameters like applied pressure and operating time on flux, percentage water recovery, and salt rejection. From experimental observations, the membrane was found to exhibit 62.50% water recovery and 86.35% salt rejection with a maximum water flux of 4.85 L/m².h at an optimized feed pressure of 8 kg /cm². Further research was carried out by passing the concentrate solution through a UV module at 254 nm to prevent bacterial contamination. Additionally, the physicochemical parameters were assessed, and sensory evaluation studies were conducted to explore the final product's properties. The concentrate and permeate CW shelf-life was enhanced from 2 h to 30 days by refrigerating the samples at 4°C. Finally, the cost estimation of the designed system is provided to verify process scale-up and commercialization feasibility.