Filippou Polychronis, Mitrouli Soultana T, Vareltzis Patroklos
Laboratory of Food and Agricultural Industries Technologies, Chemical Engineering Department, Aristotle University of Thessaloniki, GR541 24 Thessaloniki, Greece.
Laboratory of Natural Resources and Renewable Energies, Chemical Process and Energy Resources Institute (CPERI), Centre for Research and Technology-Hellas (CERTH), 6th km Charilaou-Thermi Road, GR570 01 Thessaloniki, Greece.
Membranes (Basel). 2022 Mar 23;12(4):353. doi: 10.3390/membranes12040353.
The vinification process produces a considerable amount of waste. Wine lees are the second most generated byproduct, representing around 14% of total vinification wastes. They are a valuable source of natural antioxidants, mainly polyphenols, as well as organic acids, such as tartaric acid. This paper deals with the application of an integrated, environment friendly membrane separation process to recover polyphenols and organic acids. A two-step membrane process is described, consisting of an ultra- and a nano-filtration process. The physicochemical and antioxidant properties of all the process streams were determined. High Pressure Liquid Chromatography (HPLC) was employed for identifying certain individual organic acids and polyphenols, while the antioxidant potential was determined by the 2,2'-diphenyl-1-picrylhydrazyl radical) (DPPH) radical scavenging ability and ferric reducing ability. A liquid concentrate stream containing 1351 ppm of polyphenols was produced and then spray dried. The resulting powder retained most of the polyphenols and antioxidant properties and was successfully applied to a real food system to retard lipid oxidation, followed by Thiobarbituric Acid Reactive Substances (TBARS) and the determination of oxymyoglobin content. The results show that membrane separation technology is an attractive alternative process for recovering value-added ingredients from wine lees.
葡萄酒酿造过程会产生大量废弃物。酒泥是第二大产生量的副产物，约占葡萄酒酿造废弃物总量的14%。它们是天然抗氧化剂（主要是多酚）以及酒石酸等有机酸的宝贵来源。本文探讨了一种集成的、环境友好型膜分离工艺在回收多酚和有机酸方面的应用。描述了一种两步膜工艺，包括超滤和纳滤过程。测定了所有工艺流的物理化学和抗氧化性能。采用高压液相色谱（HPLC）鉴定某些特定的有机酸和多酚，同时通过2,2'-二苯基-1-苦基肼自由基（DPPH）清除能力和铁还原能力测定抗氧化潜力。制备了一种含有1351 ppm多酚的浓缩液流，然后进行喷雾干燥。所得粉末保留了大部分多酚和抗氧化性能，并成功应用于实际食品体系以延缓脂质氧化，随后测定硫代巴比妥酸反应性物质（TBARS）和氧合肌红蛋白含量。结果表明，膜分离技术是从酒泥中回收增值成分的一种有吸引力的替代工艺。
