Photonic crystals in biology - NanoTR-VI

PPoster Session, Thursday, June 17Theme F686 - N1123Formation of Self-Assembled Alpha-Lactalbumin Nanotubes and Alpha-Lactalbumin Nanoparticlesand Their Behavior in Model Gastro-Intestinal System11Sibel KarakayaP P* and UNihan BaUP1PEge Univ., Fac Engn., Dept. Food Engn., zmir, TurkeyAbstract- In this study, alpha-lactalbumin nanotubes and nanoparticles have been formed by using whey as a starting material.Model molecule Brillant Blue encapsulation capacity of nanoparticles and release of nanoencapsulated Brillant Blue molecule inmodel gastro-intestinal system have also been investigated.The field of nanotechnology has experienced significantgrowth over the last ten years. Currently, the market ofnanotechnology products in the food industry approaches theUS$ 1 billion and has to potential to grow more than US$ 20billion in the next decade [1]. In recent years, the use ofenzymatic hydrolysis to improve functional properties offood proteins and induce specific structural changes inproteins causing the resultant peptides to self-assemble intohighly ordered and well defined nanostructures has attractedmajor attention from scientific area as well as food industry[2]. Whey as a rich source of protein is a waste productobtained from cheese manufacturing. Whey components willincreasingly be preferred as ingredients for functional foodsand nutraceuticals[3]. The growth of -lactalbumin nanotubesand their dimensions was analyzed. Alpha-lactalbumin waspurified from bovine milk. The cylinder diameter wascalculated to be 19.9 (2) nm and the cavity 8.7 (7) nm [4].In the present study, self-assembled -lactalbuminnanotubes and -lactalbumin nanoparticles and behavior of -lactalbumin nanoparticles in model gastro-intestinal systemwere investigated. Nanotubes were imaged by usingTransmission Electron Microscopy (TEM).For the isolation of -lactalbumin from whey, protein wasprecipitated by the procedure of salting out (80% saturatedsalt solution) at isoelectric point. SDS-Page analysis showedthat pure -lactalbumin could be obtained (Figure 1).50 °C in the presence of calcium cation (ratio of molecalcium/mole -lactalbumin: 2.263) are shown in Figure 2.Figure 2. TEM image of nanotubesStandardmarkerBA- lb-lacEncapsulation capacity of -lactalbumin nanoparticles wascalculated as 86.076%. In vitro release of nanoencapsulatedBrillant Blue molecule after model gastro-intestinal digestionwas 42.49%.In conclusion, this study revealed that nanotubes could beformed via self assembly of -lactalbumin isolated fromwhey and encapsulation with -lactalbumin nanoparticlescould be an alternative to microencapsulation.StandardmarkeraAt isoelectricpointSalting outSalting out atisoelectricpoint-lacbFigure 1. a) protein fraction of whey, b) protein fraction ofdialysates isolated from whey by using different precipitationmethod. BA: Bovine serum albumin; - lb: -lactoglobulin; -lac: -lactalbuminHT*Corresponding author: sibel.karakaya@ege.edu.trT[1] Acosta, E., 2009. Bioavailability of nanoparticles in nutrientand nutraceutica delivery, Current Opinion in Colloid andInterface Science, 14: 3-15.[2] Ipsen, R. and Otte, J., 2007. Self-assembly of partiallyhydrolysed -lactalbumin, Biotechnology Advances, 25: 602-605.[3] Smithers, G. W., 2008. Whey and Whey proteins from “gutterto gold”, International Dairy Journal, 18:695-704.[4] Graveland-Bikker, J. F., Fritz, G., Glatter, O., Kruif, C. G.,2006. Growth and structure of -lactalbumin nanotubes, Journal ofApplied Crystallography, 39: 180-184.TEM image of nanotubes obtained from partial hydrolysesof -lactalbumin by protease and subsequent incubation at6th Nanoscience and Nanotechnology Conference, zmir, 2010 791