Physicochemical properties of skim milk powder dispersions prepared with calcium-chelating sodium tripolyphosphate, trisodium citrate, and sodium hexametaphosphate

Abstract

Due to health benefits of proteins, the demand for protein beverages has grown rapidly. Translucent protein drinks with neutral pH may have advantages over acidic beverages that may cause dental erosion, and skim milk powder (SMP) is an affordable protein ingredient. Dissociating casein micelles by calcium chelators is a well-known method to reduce SMP dispersion turbidity, but much is to be studied for physicochemical properties as affected by chelator type and concentration. The objective of the present study was to characterize physicochemical properties of dispersions with 5% (wt/vol) SMP after addition of 0 to 30 mM sodium tripolyphosphate, trisodium citrate, or sodium hexametaphosphate. The turbidity was decreased with increasing chelator concentration, with the lowest turbidity observed in the SMP dispersions with sodium hexametaphosphate. The smallest hydrodynamic diameter was observed at an intermediate chelator concentration, resulting from the balance of casein micelle dissociation and aggregation of dissociated caseins induced at an elevated ionic strength. Heating at 90°C for 5 min increased turbidity but lowered hydrodynamic diameter of SMP dispersions, with some exceptions. The morphology of SMP dispersions differed for each chelator and was also affected by chelator concentration and heating. Trisodium citrate was the most effective to demineralize colloidal calcium phosphate in casein micelles, but the amount of dissolved calcium was not directly correlated with the decreased turbidity, indicating different chelating mechanisms by each chelator. Analysis of serum calcium and phosphorus concentrations also suggested that the type and concentration of soluble and insoluble calcium phosphates and their partitioning in the serum and casein micelles were dynamically changed by the studied parameters to affect dispersion turbidity and structures of casein micelles. Findings from the present study may be used to formulate translucent beverages incorporating SMP and other casein micelle ingredients.

Quercetin inhibits calcium oxalate crystallization and growth but promotes crystal aggregation and invasion

“…These concentration-dependent inhibitory effects might be the direct mechanism to hamper development and slow progression of kidney stone. However, the inhibitory effects of quercetin seems to be less potent than those of the well-known strong calcium-chelating agents, such as ethylenediaminetetraacetic acid (EDTA), sodium citrate and potassium citrate ( Carvalho et al, 2017 ; Choi and Zhong, 2020 ; Chutipongtanate et al, 2012 ; Doizi et al, 2018 ). Nevertheless, using the natural compound should be safer as it may introduce fewer toxic effects as compared with the more potent calcium-chelating chemicals, particularly EDTA.…”

The Influence of Sodium Hexametaphosphate Chain Length on the Physicochemical Properties of High-Milk Protein Dispersions

“…Therefore, the concentration of added SHMP influenced the zeta potential in heated 6% protein dispersion, but the chain length of added SHMP did not. Choi and Zhong (2020) [20] reported that when SHMP was added to 5% skim milk powder dispersions at higher concentrations, there was an increase in the phosphate and calcium in the serum phase, which increased the ionic strength that lowered electrophoretic mobility and, therefore, the measured zeta potential for those dispersions. Unheated 8% protein dispersion containing no SHMP had a zeta potential of −20.25 mV.…”

Recombined Egg Yolk Granules with Controllable Particle Sizes for Quercetin Delivery - A Structure-Activity Relationships Study

“…By varying the surfactant aggregation states (monomeric or micellar) and concentration ratio of both components, soluble and insoluble complexes of nano-to micro-size can be obtained [4]. Choi and Zhong used different calcium-chelators to control the hydrodynamic diameter (Dh) of casein micelles [5]. The smallest Dh was observed at an intermediate chelator concentration resulting from the balance of casein micelle dissociation and aggregation of dissociated caseins by an elevated ionic strength [5].…”

“…Choi and Zhong used different calcium-chelators to control the hydrodynamic diameter (Dh) of casein micelles [5]. The smallest Dh was observed at an intermediate chelator concentration resulting from the balance of casein micelle dissociation and aggregation of dissociated caseins by an elevated ionic strength [5]. Zhou and co-workers employed chitosan and stearic acid conjugated chitosan to regulate the size and improve the water solubility of high-density egg yolk lipoprotein.…”