Heat stability improvement of antimicrobial whey proteins from yak milk and colostrum at various acidic conditions Shimo Shimo Peter1,2,*, Xiaoyun WU1,2, Xuezhi Ding1,2, Ping Yan1,2 Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou-730050, China 1Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou-730050, China 2Key Laboratory of Yak Breeding Engineering, Lanzhou, 730050, China *Corresponding author's e-mail: shimope_2000@yahoo.com
Online published on 7 October, 2016. Abstract The aim of this study was to characterize the effect of heat denaturation on Immunoglobulin G (IgG) and Lactoferrin (LF) inyak milk and colostralliquidwheyat mediumacidicconditionsinpresenceofprotectants(CaCl2;Glyceroland Sodium Dodecyl Sulphate - SDS). Results indicated significant (P < 0.05) heat stability improvement of IgG and LF in liquid whey samples at medium acidic and temperature (72 - 90°C) with less precipitates formation regardless of type of protectants added especially at pH 3.5 and 4.6. The mean concentration values for IgG percentage reduction (72 – 90°C; pH 3.5 – 5.5; protectants) ranged from 6 to 26% and 15 to 31% in yak milk and colostral liquid whey, respectively. The percentage of heat denaturation effect for LF ranged from 11 to 32% and 14 to 38% in yak milk and colostral liquid whey, respectively. Application of glycerol in both environmental processing conditions was the most effective in heat stability improvement followed by SDS and CaCl2. Top Keywords Heat stability, Immunoglobulin G, Lactoferrin, Protectants, Liquid whey, Yak colostrum/milk. Top |