Effect of selected Hofmeister salts on textural and rheological properties of nonfat cheese

Abstract

Three Hofmeister salts (HS; sodium sulfate, sodium thiocyanate, and sodium chloride) were evaluated for their effect on the textural and rheological properties of nonfat cheese. Nonfat cheese, made by direct acidification, were sliced into discs (diameter=50 mm, thickness=2 mm) and incubated with agitation (6 h at 22°C) in 50 mL of a synthetic Cheddar cheese aqueous phase buffer (pH 5.4). The 3 HS were added at 5 concentrations (0.1, 0.25, 0.5, 0.75, and 1.0 M) to the buffer. Post-incubation, cheese slices were air dried and equilibrated in air-tight bags for 18 h at 5°C before analysis. Small amplitude oscillatory rheology properties, including the dynamic moduli and loss tangent, were measured during heating from 5 to 85°C. Hardness was determined by texture profile analysis. Acid-base buffering was performed to observe changes in the indigenous insoluble (colloidal) calcium phosphate (CCP). Moisture content decreased with increasing HS concentration. Cheeses incubated in high concentrations of SCN(-) softened earlier (i.e., loss tangent=1) compared with other HS treatments. Higher melting temperature values were observed for cheeses incubated in high concentrations of SO(4)(2-). Hardness decreased in cheeses incubated in buffers with high concentrations of SCN(-). The indigenous CCP profile of nonfat cheese was not greatly affected by incubation in Cl(-) or SCN(-), whereas buffers with high concentrations of SO(4)(2-) reduced the acid-base buffering contributed by CCP. The use of high concentrations (1.0M) of SCN(-) for incubation of cheeses resulted in a softer protein matrix at high temperatures due to the chaotropic effect of SCN(-), which weakened hydrophobic interactions between CN. Cheese samples incubated in 1.0M SO(4)(2-) buffers exhibited a stiffer protein matrix at high temperatures due to the kosmotropic effect of SO(4)(2-), which helped to strengthen hydrophobic interactions in the proteins during the heating step. This study showed that HS influenced the texture and rheology of nonfat cheese probably by altering the strength of hydrophobic interactions between CN.

Exopolysaccharide from marine microalgae belonging to the Glossomastix genus: fragile gel behavior and suspension stability

“…EPS solutions at various concentrations have been prepared in NaCl, a lyotropic salt (strengthening hydrophobic interactions [ 47 ]), or KSCN, a chaotropic salt (weakening hydrophobic interactions [ 47 ]), according to the Hofmeister series to study the impact of salinity on their rheology. The flow curves for the EPS-3707 and EPS-3688 solutions in NaCl 0.15 mol L −1 are compared with those in water in Figure 3(a,b) , respectively.…”

Probing the structure-holding interactions in cheeses by dissociating agents – A review and an experimental evaluation with emmental cheese

“…Hence, the concentration of colloidal calcium increases proportionally with the concentration of casein at drainage, leading to the formation of a highly mineralized, cohesive para-κ-casein matrix, with a calcium-casein ratio close to that of the casein micelles in milk ( Gagnaire et al., 2002 ). Previous studies suggest that, within the casein micelles, several interactions take place among the individual casein chains, such as: (1) weak hydrophobic interactions; (2) salt bridges; and (3) calcium binding to caseins that result in the formation of colloidal calcium phosphate (CCP) ( Hinrichs and Keim, 2007 ; Lucey and Horne, 2018 ; Stankey et al., 2011 ). In gel-like systems based on casein, such as cheese, literature proposes that self-association of casein micelles is also driven by different interactions, such as hydrophobic interactions and electrostatic ones ( Horne, 1998 ).…”

The effect of emulsifying salts on the turbidity of a diluted milk system with varying pH and protein concentration

“…In the case of phosphates, the distribution of charges on phosphate and casein molecules and the pK a values all contribute to the potential for ES-protein interaction. These ES might play a role similar to salts in the Hofmeister series that work at the protein-water interface to change the conformation of the protein due to interaction with the water (Stankey et al, 2011). Some salts in the Hofmeister series (perchlorate, nitrate, and bromide) have been found to be misplaced in terms of the dissociative effects that they have on β-casein (Sawyer and Puckridge, 1973).…”