Enhancing the nutritional quality and concentration of noni, pineapple, and dragon fruit juice mixture using osmotic membrane distillation

Abstract

This research investigates the mixing of dragon fruit, noni, and pineapple juices to create a more nutritious functional beverage, followed by the concentration of the mixed juice using osmotic membrane distillation. The optimum mixture formulation concerning the nutrient value of the juice was 58.2 % dragon fruit, 25 % noni fruit, and 16.8 % pineapple juice. During the concentration process using osmotic membrane distillation, feed temperature positively impacted membrane flux, while the concentration of the draw solution had limited effects due to insufficient mass transport enhancement. The concentrated mixed juice retained most of its vitamin C and antioxidant properties, although significant thermal degradation occurred at 50 °C. The draw solution concentration also influenced vitamin C content, likely due to the interaction between potassium sorbate and vitamin C. While total phenolic content decreased, identifying the conditions affecting its degradation proved challenging. The optimized concentrated juice was obtained at a feed temperature of 46.5 °C and a draw solution concentration of 1 M, resulting in 87.1 DPPH % inhibition, 126.8 mg/100 mL of vitamin C, and 45.7 mg/100 g of total phenolic content. This study improves the sensory qualities of noni juice while preserving its nutritional integrity, marking a significant advancement in healthier fruit beverages, with membrane technology effectively concentrating the juice with minimal degradation.