Influence of milk protein concentrates with modified calcium content on enteral dairy beverage formulations: Physicochemical properties

Abstract

Because of their high protein and low lactose content, milk protein concentrates (MPC) are typically used in the formulation of ready-to-drink beverages. Calcium-mediated aggregation of proteins during storage is one of the main reasons for loss of storage stability of these beverages. Control and calcium-reduced MPC [20% calcium-reduced (MPC-20) and 30% calcium-reduced (MPC-30)] were used to evaluate the physicochemical properties in this study. This study was conducted in 2 phases. In phase I, 8% protein solutions were prepared by reconstituting the 3 MPC and adjusting the pH to 7. These solutions were divided into 3 equal parts, 0, 0.15, or 0.25% sodium hexametaphosphate (SHMP) was added, and the solutions were homogenized. In phase II, enteral dairy beverage formulations containing MPC and a mixture of gums, maltodextrin, and sugar were evaluated following the same procedure used in phase I. In both phases, heat stability, apparent viscosity, and particle size were compared before and after heat treatment at 140°C for 15 s. In the absence of SHMP, MPC-20 and MPC-30 exhibited the highest heat coagulation time at 30.9 and 32.8 min, respectively, compared with the control (20.9 min). In phase II, without any addition of SHMP, MPC-20 exhibited the highest heat coagulation time of 9.3 min compared with 7.1 min for control and 6.2 min for MPC-30. An increase in apparent viscosity and a decrease in particle size of reconstituted MPC solutions in phases I and II with an increase in SHMP concentration was attributed to casein micelle dissociation caused by calcium chelation. This study highlights the potential for application of calcium-reduced MPC in dairy-based ready-to-drink and enteral nutrition beverage formulations to improve their heat stability.

Influence of milk protein concentrates with modified calcium content on enteral dairy beverage formulations: Storage stability

“…Partial demineralization of casein was proven to improve functional properties of MPC (Marella et al, 2015) as well as cause greater dissociation of casein micelles in skim milk (Xu et al, 2016). An earlier part of this study, determining the physiochemical properties of calcium-reduced MPC, proved that MPC-20 improved heat stability in 8% protein formulations without any chelating agent (Pandalaneni et al, 2018). The objective of the current study was to further investigate the influence of calcium-reduced MPC and the presence of a chelating agent on the storage stability of high-protein enteral dairy beverages.…”

“…This can be attributed to casein micelle dissociation, resulting in heat-induced protein reaggregates with casein micelles in the presence of SHMP. From a previously published study by Pandalaneni et al (2018), it was evident that casein micelles were not completely dissociated in control formulation as compared with calcium-reduced MPC when 0.15% SHMP was added. Hence, it can be assumed that association of heat-induced reaggregates with casein micelles can occur during retort sterilization.…”

“…The apparent viscosity of retort sterilized dairy beverages was measured using a controlled stress rheometer (ATS RheoSystems, Bordentown, NJ) in a bob and cup geometry at 20°C (Pandalaneni et al, 2018). A sample volume of 13 mL was used for measurement of apparent viscosity at a shear rate of 100 s −1 and compared statistically.…”

Invited review: Understanding the behavior of caseins in milk concentrates

“…Excessive calcium activity has been attributed as a problem in heat stability of MPC with high protein concentration (Crowley et al, 2015a). Recently, calcium-depleted MPC have been suggested as possible value added for ready to drink and enteral formulations (Eshpari et al, 2014;Marella et al, 2015;Pandalaneni et al, 2018); however, it is important to also control the reconstitution conditions, as this will further modify the ionic balance (Eshpari et al, 2014(Eshpari et al, , 2015Lin et al, 2018;Liu et al, 2019). Reconstituted MPC powders made with partially acidified milk containing lower soluble calcium and phosphate exhibit poor thermal stability compared with MPC powders made with milk at its natural pH (Eshpari et al, 2014).…”

“…Reconstituted MPC powders made with partially acidified milk containing lower soluble calcium and phosphate exhibit poor thermal stability compared with MPC powders made with milk at its natural pH (Eshpari et al, 2014). The thermal stability of the acidified MPC dispersions improves by restoration of pH and the serum composition through dialysis against milk, or using permeate as a reconstituting medium (Eshpari et al, 2014;Crowley et al, 2014;Lin et al, 2018;Pandalaneni et al, 2018). By comparing samples with similar pH and protein, calcium, and phosphate concentrations, it was shown that the presence of nonsedimentable caseins plays a major role in determining the thermal stability of these MPC dispersions, by assisting in stabilization of the colloidal suspension (Eshpari et al, 2014;Lin et al, 2018).…”