Influence of Glycomacropeptide on Rehydration Characteristics of Micellar Casein Concentrate Powder

Abstract

Glycomacropeptide (GMP) shows potential for enhancing the rehydration properties of high-protein dairy powders due to its hydrophilic nature. This study involved formulating micellar casein concentrate (MCC) solutions (8.6% final protein content) with 0, 10, and 20% GMP as a percentage of total protein, and investigated the physicochemical and rehydration properties of the resultant freeze-dried powders (P-MCC-0G, P-MCC-10G, and P-MCC-20G, respectively). The surface charges of caseins in the control MCC and 10 or 20% GMP blended solutions were −25.8, −29.6, and −31.5 mV, respectively. Tablets prepared from P-MCC-10G or P-MCC-20G powders displayed enhanced wettability with contact angle values of 80.6° and 79.5°, respectively, compared with 85.5° for P-MCC-0G. Moreover, blending of GMP with MCC resulted in faster disintegration of powder particles during rehydration (i.e., dispersibility) compared to P-MCC-0G. Faster and more extensive release of caseins from powder particles into solution was evident with the increasing proportion of GMP, with the majority of GMP released within the first 15 min of rehydration. The results of this study will contribute to further development of formulation science for achieving enhanced solubility characteristics of high-protein dairy powder ingredients, such as MCC.

Raman spectra of micellar casein powders prepared with wet blending of glycomacropeptide and micellar casein concentrate

“…The results for physicochemical and rehydration characteristics of the powder samples have been reported and discussed in a previous study in greater detail (Panthi et al . 2021). Briefly, the powder samples 0G, 10G and 20G had moisture content of 4.0, 3.5 and 4.4% (w/w), protein content (w/w, dry basis) of 88.5, 85.8, and 83.8%, and ash content of 8.04 7.85 and 7.54 (w/w, dry basis), respectively.…”

“…The dispersion performance of these powders in ultrapure water was in the order 20G > 10G > 0G (Panthi et al . 2021). The use of freeze‐dried powders was expected to minimise the influence of structural inhomogeneity within powder particles, because of similar surface and internal properties, for linking the powder dispersion characteristics with chemical interactions between macromolecules.…”

“…Spray‐dried MCC (MCC‐SD) and GMP powder (GMP‐SD) were acquired from commercial suppliers and three freeze‐dried MCC powders were prepared by blending GMP at the rate of 0, 10 and 20% of total protein in MCC solution at laboratory scale (0G, 10G, 20G), as described in Panthi et al . (2021). Powder tablets were prepared by applying a 5000 kg load in a hydraulic press (Atlas Manual 15 T Hydraulic Press; Specac Ltd, Orpington, UK).…”

“…The experiment was designed to compare the spectral characteristics of powder tablets that were obtained blending GMP at the rate of 0, 10 and 20% in MCC prior to drying in triplicate ( n = 3), as described in Panthi et al . (2021). Chemometric analysis of Raman spectra was performed using MetaboAnalyst online software (v. 5.0, http://www.metaboanalyst.ca; Chong et al .…”

“…For example, the incorporation of glycomacropeptide (GMP) in MCC solution before drying was found to enhance rehydration characteristics (wetting and dissolution) of the subsequent powder compared to control MCC powder with no added GMP (Panthi et al . 2021). Understanding the chemical changes that occurred within such powders in pure form or blended form is important to improve or predict functional characteristics.…”