Rudolph Alexander, El-Mohamad Amna, McHardy Christopher, Rauh Cornelia
Department of Food Biotechnology and Food Process Engineering, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany.
Foods. 2021 Mar 16;10(3):626. doi: 10.3390/foods10030626.
Fruits have an important economic impact in the context of plant-based food production. The consumption of fruit juices, mostly produced from concentrates, is particularly noteworthy. Conventional concentration methods do not always enable a sustainable and gentle concentration. The innovative gas hydrate technology addresses this point with its energy-saving, gentle character, and high concentration potential. In this study, the concentration of fruit juices and model solutions using CO2 hydrate technology was investigated. To find a suitable operating point for hydrate formation in the used bubble column, the hydrate formation in a water-sucrose model solution was evaluated at different pressure and temperature combinations (1, 3, 5 °C and 32.5, 37.5, 40 bar). The degrees of concentration indicate that the bubble column reactor operates best at 37.5 bar and 3 °C. To investigate the gentle processing character of the hydrate technology, its quantitative effects on vitamin C, betanin, polyphenols, and carotenoids were analyzed in the produced concentrates and hydrates via HPLC and UV/VIS spectrophotometry. The results for fruit juices and model solutions imply that all examined substances are accumulated in the concentrate, while only small amounts remain in the hydrate. These amounts can be related to an inefficient separation process.
在植物性食品生产背景下，水果具有重要的经济影响。尤其值得注意的是大多由浓缩物生产的果汁的消费情况。传统浓缩方法并不总能实现可持续且温和的浓缩。创新的气体水合物技术以其节能、温和的特性以及高浓缩潜力解决了这一问题。在本研究中，对使用二氧化碳水合物技术浓缩果汁和模型溶液进行了研究。为了在所用鼓泡塔中找到水合物形成的合适操作点，在不同压力和温度组合（1、3、5℃以及32.5、37.5、40巴）下评估了水 - 蔗糖模型溶液中的水合物形成情况。浓缩程度表明鼓泡塔反应器在37.5巴和3℃下运行最佳。为了研究水合物技术的温和加工特性，通过高效液相色谱法（HPLC）和紫外/可见分光光度法对所生产的浓缩物和水合物中的维生素C、甜菜红素、多酚和类胡萝卜素的定量影响进行了分析。果汁和模型溶液的结果表明，所有检测物质都在浓缩物中积累，而水合物中仅残留少量。这些量可能与分离过程效率低下有关。
