Pigments membrane separation

UF is used to clarify various fruit juices (apple, grape, pear, pineapple, cranberry, orange, lemon) which are recovered as the permeate [Blanch et al., AlChE Symp. Ser. 82, 59 (1986)]. UF has also been used to remove pigments and reducing browning in wine production [Kosikowski in Membrane Separations in Biotechnology, McGregor (ed.), Marcel Dekker, New York, 1986]. 

Membrane degumming. Membrane separation has also been evaluated as an alternative process to conventional oil refining processing. Ultrafiltration (UF) and nanofiltration (NF) membranes separate phospholipids almost completely, and FFAs, pigments, and other components can also be removed with the phospholipids to a certain extent. Less effort is required in the later processing steps. 

For separation of thylakoid membrane components, thylakoid membranes of the cyanobacterium Synechococcus elongatus were solubilised by Triton X-100 (mass ratio Tritonichl = 25, final concentration of Triton 17.,v/v) or by SDS (mass ratio SDS chl = 50, final concentration of SDS 2.57.,v/v). For details see (5). E1ectrophoresis on gradient polyacrylamide gel (5-107., in case of pigment-proteins separation, 10-207. in case of polypeptide analysis) was performed in the buffer system described earlier (5,8). 

The redox electrode model of photosynthesis illustrating the mechanism of photon-induced charge separation and electron transfer processes in a pigmented BLH separating two aqueous solutions. P and P denote the pigment in the ground and excited state, respectively. A = electron acceptor, D = electron donor, A and are reduced and oxidized forms. Subscripts o and i indicate the outer and inner side of the membrane, and P is oxidized P. (Adapted from Nature, 219, 272, 1968 227, 1232, 1970). 

Bile is an aqueous solution of bile salts, inorganic salts, bile pigments, fats, cholesterol, and others. The physiology of bile secretion is not simple, as it involves the active excretion of organic solutes from the blood to the bile. Bile is collected directly from the liver cells through separate channels, without being mixed with blood. The liver cell membrane incorporates extremely fine passages that permit bile secretion. 

The retinal pigmented epithelium (RPE) is in intimate, anatomic, and functional contact with the retina. Separated from the retina by Bruch s membrane, the RPE serves to regulate nutrients to the retina, phagocytize retinal debris, remove metabolic end products, and control the visual cycle. From a mass transport perspective, the RPE represents the outer BRB. 

The hydrolysis of caroteno-proteins for the production of astaxanthin using protease was developed in an enzymatic membrane bioreactor [19], in which the concentration of the protein fraction by ultrafiltration and the separation of the pigments in the permeate were simultaneously carried out. 

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