Bargeman Gerrald, Houwing Joukje, Recio Isidra, Koops Geert-Henk, van der Horst Caroline
NIZO Food Research, P.O. Box 20, 6710 BA Ede, The Netherlands.
Biotechnol Bioeng. 2002 Dec 20;80(6):599-609. doi: 10.1002/bit.10419.
For the isolation of the ingredients required for functional foods and nutraceuticals generally membrane filtration has too low a selectivity and chromatography is (too) expensive. Electro-membrane filtration (EMF) seems to be a breakthrough technology for the isolation of charged nutraceutical ingredients from natural sources. EMF combines the separation mechanisms of membrane filtration and electrophoresis. In this study, positively charged peptides with antimicrobial activity were isolated from an alpha(s2)-casein hydrolysate using batch-wise EMF. alpha(s2)-Casein f(183-207), a peptide with strong antimicrobial activity, predominated in the isolated product and was enriched from 7.5% of the total protein components in the feed to 25% in the permeate product. With conventional membrane diafiltration using the same membrane (GR60PP), isolation of this and other charged bioactive peptides could not be achieved. The economics of EMF are mainly governed by the energy costs and the capital investment, which is affected by the flux of the desired peptide. A maximum average transport rate of alpha(s2)-casein f(183-207) during batch-wise EMF of 1.2 g/m2. h was achieved. Results indicate that an increase in the hydrolysate (feed) concentration, the applied potential difference and the conductivity of the permeate and electrode solutions, and a reduction in the conductivity of the feed result in a higher transport rate of alpha(s2)-casein f(183-207). This is in line with the expectation that the transport rate is improved when the concentration, the electrical field strength, or the electrophoretic mobility is increased, provided that the electrophoretic transport predominates. The expected energy consumption of the EMF process per gram of peptide transported was reduced by approximately 50% by applying a low overall potential difference and by processing desalinated hydrolysate. Considerable improvements in transport rate, energy efficiency, and process economics seem to be attainable by additional optimization of the process parameters and the EMF module design.
对于功能性食品和营养保健品所需成分的分离，通常膜过滤的选择性过低，而色谱法成本（过高）。电膜过滤（EMF）似乎是一种从天然来源分离带电荷营养成分的突破性技术。EMF结合了膜过滤和电泳的分离机制。在本研究中，使用分批式EMF从α(s2)-酪蛋白水解物中分离出具有抗菌活性的带正电荷肽。α(s2)-酪蛋白f(183 - 207)是一种具有强抗菌活性的肽，在分离产物中占主导地位，从进料中总蛋白质成分的7.5%富集到渗透产物中的25%。使用相同的膜（GR60PP）进行传统的膜渗滤，无法实现这种及其他带电荷生物活性肽的分离。EMF的经济性主要由能源成本和资本投资决定，而资本投资受所需肽通量的影响。在分批式EMF过程中，α(s2)-酪蛋白f(183 - 207)的最大平均传输速率达到1.2 g/m²·h。结果表明，水解物（进料）浓度、施加的电位差以及渗透液和电极溶液的电导率增加，进料电导率降低，会导致α(s2)-酪蛋白f(183 - 207)的传输速率更高。这符合预期，即在电泳传输占主导的情况下，当浓度、电场强度或电泳迁移率增加时，传输速率会提高。通过施加较低的总电位差和处理脱盐水解物，每克传输肽的EMF过程预期能耗降低了约50%。通过进一步优化工艺参数和EMF模块设计，似乎可以在传输速率、能源效率和工艺经济性方面取得显著改进。
