Stoyanova Yoana, Lazarova-Zdravkova Nevena, Peshev Dimitar
Department of Biotechnology, University of Chemical Technology and Metallurgy, 1576 Sofia, Bulgaria.
Department of Chemical Engineering, University of Chemical Technology and Metallurgy, 1576 Sofia, Bulgaria.
Membranes (Basel). 2025 Jan 11;15(1):21. doi: 10.3390/membranes15010021.
This study explored the batch membrane filtration of 40% ethanol extracts from spent lavender, containing valuable compounds like rosmarinic acid, caffeic acid, and luteolin, using a polyamide-urea thin film composite X201 membrane. Conducted at room temperature and 20 bar transmembrane pressure, the process demonstrated high efficiency, with rejection rates exceeding 98% for global antioxidant activity and 93-100% for absolute concentrations of the target components. During concentration, the permeate flux declined from 2.43 to 1.24 L·m·h as the permeate-to-retentate-volume ratio increased from 0 to 1. The process resistance, driven by osmotic pressure and concentration polarization, followed a power-law relationship with a power value of 1.20, consistent with prior nanofiltration studies of rosmarinic acid solutions. Notably, no membrane fouling occurred, confirming the method's scalability without compromising biological activity. The antioxidant activity, assessed via the DPPH method, revealed that the retentate exhibited double the activity of the feed. Antibacterial assays using broth microdilution showed that the retentate inhibited by 73-96% and by 97-98%, making it the most active fraction. These findings validate the effectiveness of the X201 membrane for concentrating natural antioxidants and antibacterial agents from lavender extract under sustainable operating conditions.
本研究使用聚酰胺 - 脲复合X201膜，探索了对废弃薰衣草40%乙醇提取物进行分批膜过滤的过程，该提取物含有迷迭香酸、咖啡酸和木犀草素等有价值的化合物。在室温及20巴跨膜压力下进行该过程，结果表明其效率很高，对总抗氧化活性的截留率超过98%，对目标成分的绝对浓度截留率为93 - 100%。在浓缩过程中，随着透过液与截留液体积比从0增加到1，透过通量从2.43 L·m·h下降到1.24 L·m·h。由渗透压和浓差极化驱动的过程阻力与幂律关系相符，幂值为1.20，这与之前对迷迭香酸溶液的纳滤研究一致。值得注意的是，未发生膜污染，这证实了该方法在不影响生物活性的情况下具有可扩展性。通过DPPH法评估抗氧化活性表明，截留物的活性是进料的两倍。使用肉汤微量稀释法进行的抗菌试验表明，截留物对 和 的抑制率分别为73 - 96%和97 - 98%，使其成为活性最高的部分。这些发现验证了X201膜在可持续操作条件下从薰衣草提取物中浓缩天然抗氧化剂和抗菌剂的有效性。
