17B-2 |
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R. R. LU, S. Y. Xu, and Z. Wang. School of Food Science & Technology, Southern Yangtze University, 170 Huihe Rd., Wuxi, Jiangsu Province, 214036, China Lactoferrin is a glycoprotein existed in external secretions such as milk, especially colostrum. Lactoferrin has various bioactive functions such as broad-spectrum antimicrobial activity, promotion of iron transfer and absorption. Therefore, it has great potential to be widely used in foods, pharmaceuticals, and cosmetics. Nowadays, lactoferrin of high purity could be prepared on laboratory scale with very high cost. The objective of this study is to effectively separate and purify lactoferrin on a large scale with economic cost and high production rate. A procedure was described to isolate the lactoferrin from colostrums. It consisted of two stages, namely separating and concentrating lactoferrin by a two-step ultrafiltration with membranes which molecular weight cut-off were 150,000Da and 10,000Da respectively, and then purifying the crude lactoferrin product with a SP-Sepharose Fast Flow cation exchange chromatography. The concentration of lactoferrin was determined by ELISA. The tangential flow rate 4 L/min was chosen to lighten polarization. Flux was proportionate to pressure drop when it was lower than critical value 0.15MPa. The optimal operating temperature was 50 degree C. A resistances-in-series mathematic flux model was developed to predict the practical performance. The purity of lactoferrin in UF-2 retentate was about 30%. Lactoferrin was eluted with 0.1 mol/L NaCl by using a column sized by 7.0*20 cm at the flow rate 2-6 L/min which was 100-fold than normal rate. The SDS-PAGE showed a single band at 80,400Da, and the purity of the final lactoferrin product was 94%. The results suggest that the crude lactoferrin product could be used for food ingredient in infant foods due to its nutritional benefits. The strong cation exchanger had a potential advantage for producing lactoferrin which purity was higher than 90%. The final product could be used for pharmaceutical applications.
Session 17B, Dairy Foods: General
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