Effect of pH on antigen-binding activity of IgG from bovine colostrum upon heating

The Influence of Heat Treatment in Liquid Whey at Various pH on Immunoglobulin G and Lactoferrin from Yak and Cows’ Colostrum/Milk

“…The conformation change in the IgG molecule occurred during heat exposure reduces antigen-binding activity of this protein Calmettes et al [62], whereas, antigen-binding site of IgG is more sensitive to heat compared to other part of the molecule [21,22]. Trujillo et al [19] reported that Immunoglobulins, are species specific on heat sensitivity particularly IgG such as on bovine, caprine and ovine.…”

“…high stability in a decreasing order from IgG, IgA and IgM as well as varies among species [17][18][19]. The conformation changes in the IgG molecule which occurs during heat exposure reduces antigen-binding activity of this protein Calmettes et al [20] and antigen-binding site of IgG is more sensitive to heat compared to other part of the molecule [21,22]. On the other hand, LF are denatured by heat treatment too, therefore pasteurizing milk might affect LF unless mild heat treatment is applied [23,24].…”

The development of a novel technique to evaluate binding between probiotic bacteria and phospholipids, and the creation of a dairy-based food product rich in milk bioactives

“…Immunoglobulins are among the most heat-stable whey proteins, though this varies with the subtype (IgG being the most resistant) (Dominguez et al 2001). Retention of their bioactivity post-processing is of concern, however, due to their potential denaturation and loss of associated beneficial functions.…”

“…pH 4.5). However, this effect may be less severe when in the presence of milk or colostrum, likely due to inherent protection by milk proteins and salts (Dominguez et al 2001). Chen et al (2000) found that milk IgG could be significantly stabilized during heat processing when in the presence of 20% glycerol, 20% maltose, or 0.2% glutamic acid.…”

“…This would minimize the immunoglobulin denaturation, and perhaps that of the other whey proteins as well (Li-Chan et al 1995). Also, the presence of the other ingredients in the formulation, such as sugars and milk proteins, may actually have a protective effect on the integrity of the immunoglobulin structure, though this was not explored in this study (Chen et al 2000;Dominguez et al 2001). Microencapsulation is also an option for preserving their native structure (Chen et al 1999).…”