Technical Note: Comparison of Chromatographic Profile of Glycomacropeptide from Cheese Whey Isolated Using Different Methods

Abstract

Glycomacropeptide (GMP) has heterogeneous carbohydrates, and this attributes to its various biological activities. In this study, we compared the chromatographic profiles of GMP isolated by three methods (trichloracetic acid fractionation, ethanol precipitation, and ultrafiltration) from whey protein isolate (WPI). Seven sharp heterogeneous GMP peaks were eluted from GMP prepared by ethanol precipitation and ultrafiltration using Mono Q anionic chromatography, while only 5 peaks were seen in TCA treated sample. The TCA pretreatment recovered only sialo-GMP (glycosylated) and eliminated all contaminated proteins; however, the recovery rate was the lowest (6.7% of the initial WPI). Ethanol precipitation recovered 20.4% of GMP from WPI and 75.7% was glycosylated, but the heating process might lead to degradation of glycosidic residues. Ultrafiltration was found to be the most effective in recovering GMP. The recovery rate was 33.9% with 81.6% sialo-GMP. We concluded that carbohydrate profile of GMP varied widely and depended on the isolation method. Based on the high recovery of sialo-GMP, the combination of ultrafiltration and anionic chromatography might be a suitable and practical approach on an industrial scale.

Health effects and technological features of caseinomacropeptide

“…Ethanol precipitation recovered 20.4% CMP of which 75.7% was glycosylated, but it was suspected that the heating process involved degraded some of the sugar chains. According to Li and Mine (2004b), among the three methods, UF gave the highest recovery of CMP (33.9%), with 81.6% glycosylated CMP. However Lieske, Konrad, and Kleinschmidt (2004) reported that the pH adjustment to 7.0 during the multi-stage UF process could lead to a complete deglycosylation of CMP if a short-term surplus of NaOH was added.…”

Quantity and carbohydrate content of glycomacropeptide fractions isolated from raw and heat-treated milk

“…Vasbinder, Rollema, and de Kruif (2003) found that it was possible to precipitate the majority of the non-glycosylated forms of GMP with 12% TCA. In addition, Li and Mine (2004b) and Thoma et al (2006) reported the precipitation and isolation of non-glycosylated and glycosylated GMP fractions using TCA. To the best of our knowledge, the precipitation and fractionation of GMP induced by dialysis has not been reported previously.…”

“…It is well known that, during heating of milk, b-lactoglobulin can form a complex with k-casein at the micelle surface, which limits rennet hydrolysis of k-casein and release of GMP (Calvo, Law, & Leaver, 1995;Van Hooydonk, DeKoster, & Boerrigter, 1987). As it is not only the peptide but also the carbohydrate moieties (especially NeuNAc content) that are thought to be responsible for the various reported biological activities of GMP (Li & Mine, 2004b;Manso & Lopez-Fandino, 2004;Yvon, Beucher, Builloteau, Huerou-Luron, & Corring, 1994), and as processing conditions are likely to influence glycosylation (Ferron-Baumy, Molle, Garric, & Maubois, 1992), it is necessary to understand how milk heat treatments influence the carbohydrates bound to GMP. In this paper, the effect of milk heat treatment on the quantity of GMP recovered and the carbohydrates associated with this GMP after hydrolysis by rennet are reported.…”

Enzyme-linked immunosorbent assay for the detection of bovine rennet whey powder in milk powder and buttermilk powder

“…At higher TCA concentrations, non-glycosylated CMP becomes insoluble and only glycosylated CMP remains in solution. Consequently, the recovery of CMP decreases with increasing TCA concentration (Le´onil & Molle´, 1991;Kawakami et al, 1992;Li & Mine, 2004;Lieske & Konrad, 1996). Thus, for optimal detection of CMP in milk powder, a TCA concentration has to be selected at which both the removal of caseins and recovery of CMP are optimal.…”