Exploration of food preservatives as draw solutes in the forward osmosis process for juice concentration

• DOI: 10.1016/j.memsci.2021.119495
• Publication Date: 2021-06-09T16:20:28Z
• Authors: Keming Zhang; Xiaochan An; Yan Bai; Chong Shen; Yinpeng Jiang; Yunxia Hu
• Keywords: Osmosis; Food Preservatives

Abstract Forward osmosis (FO) technology has drawn increasingly research interests in juice concentration due to its great advantages in producing high-quality concentrated juice. However, the lack of suitable draw solutes is a significant obstacle hindering the practical application of FO for juice concentration. In this work, a series of food preservatives were systematically investigated as draw solutes in the FO system. By careful evaluation of these preservatives, we selected 4 M sodium diacetate (SDA) as one model of draw solution to concentrate grape juice in a 72-h continuous FO test. The concentrated grape juice with 5.14 folds was obtained with no loss of the titratable acidity and the vitamin C content. Moreover, the SDA accumulation in the concentrated product was only 2.0 ± 0.1 g/kg, after being diluted to regenerate juice, the preservative concentration in juice is 0.39 g/kg, which is lower than the safety limit of SDA (0.5 g/kg, FAO). Our findings demonstrate the application potential of the preservative draw solutions for juice concentration in the FO.