Using condensed water from evaporation process during production of apple juice concentrate to prepare nutritional water drink

Abstract: In order to achieve the goal of reusing of apple water, the condensed water, which was obtained from the evaporation of apple juice concentrate production, was used as raw material in this paper, and its composition and concentration were also analyzed. On this basis, the water was purified and its nutrients were concentrated through the membrane separation technologies such as ultrafiltration, reverse osmosis, and then the condensed water was developed into a natural plant water beverage. The results showed that the reducing sugar, total acidity, aroma and total phenolic content of condensed water from apple juice concentrate were 150 μg/mL, 98.5 μg/mL, 166 μg/mL, and 1.046 μg/mL, respectively, while harmful metallic elements of lead, arsenic, mercury were not detected. The content of Alicyclobacillus spp. in excess of the standards was 43 CFU/100 mL. However Alicyclobacillus spp. can be removed from the condensed water by applying with the membrane separation technology of ultrafiltration (operating conditions of 40 ℃, 0.06 MPa) and its content would reach to less than 1 CFU/100 mL. The nutrients in condensed water which was from apple juice processing can be effectively concentrated by membrane separation technology of reverse osmosis (operating conditions of 0.5 MPa, 5 ℃) , and the retention rates of reducing sugar, total acidity, aroma, and total phenol component were 95.07%, 97.61%, 87.71%, and 94.52%, respectively. Finally, if small amounts of vitamin B and vitamin C were added into this water, a drink of nutritional water with rich apple aroma can be prepared. The results in this study would lay the experimental basis for the further exploration of condensed water during apple juice concentration process and would also provide a research approach for saving water resources for Chinese apple juice concentrate companies.