On the heat stability of whey protein: Effect of sodium hexametaphosphate

Abstract

Despite a growing demand for whey protein-based drinks, their instability and lack of solubility during thermal processing is a major challenge for food product formulators. In the present study, the effects of different hydrocolloids and sodium hexametaphosphate (SHMP) on the heat stability, rheological properties, microstructure and sensory characteristics of whey protein concentrate (WPC) dispersions were evaluated. The results indicated that at pH 4, xanthan, k-carrageenan, low methoxyl pectin (LMP) and guar stabilised WPC dispersion without heat treatment, all maintained stability during pasteurisation but not sterilisation. For pH 7, for the same set of hydrocolloids, a similar trend was also observed, albeit at different concentrations. However, by adding optimum ratios of SHMP protein denaturation was retarded, particularly in the case of LMP and i-carrageenan. The highest and lowest apparent viscosities were exhibited by samples containing 0.01% and 0.15% w/w SHMP, respectively. This study highlights the potential capability of SHMP in the prevention of protein denaturation. An exact plausible stability mechanism still needs further more detailed investigation.

Stabilization of hempseed protein dispersion: Influence of sonication, hydrocolloids, and sodium hexametaphosphate

“…As can be seen, SHMP was unable to prevent instability, though it slightly improved the stability likely owing to the prevention of the exposure of hydrophobic regions via unfolding upon heat treatment (Shirashoji et al, 2010). It is already declared that phosphate ions can improve stability (Rasouli et al, 2019;Tejayadi, 2004); nonetheless, it was not probably the case here because the majority (~85%) of HPC protein was insoluble (Table 1). It is also stated that the amount of phosphate salt could affect its interaction with milk proteins:…”

“…Figure 1 shows that the acidification method highly influenced the dispersibility and solubility of HPC which was reflected in the height of the precipitate. As can be seen (Figure 1), the precipitate of the dispersions, prepared under the second and third methods, was smaller than the first one (Rasouli et al, 2019).…”

“…Phosphate-based salts also have shown gel forming capability with milk proteins as cross-linking agent (Mizuno & Lucey, 2007). SHMP has been also used for improving heat stability of whey protein-based beverage (Rasouli et al, 2019). Due to calcium contribution in whey protein gelation, calcium-binding salts have been also utilized to prevent calcium induced-protein aggregation by reducing free calcium concentration to enhance heat stability of whey protein isolates (Hebishy et al, 2019).…”

“…To increase solubility and thermal resistance of proteins, so far, various additives (hydrocolloids and chelating agents such as sodium hexametaphosphate or SHMP) and methods (ultrasound treatment and homogenization) or their combinations have been investigated (O'Sullivan et al, 2014;Pathomrungsiyounggul et al, 2010;Rasouli et al, 2019;Shen, 2007). Hydrocolloids, usually as hydrophilic macromolecules, have the capability of interacting with proteins to stabilize protein-based beverages (Patino & Pilosof, 2011;Rasouli et al, 2019). SHMP is also a tasteless and water soluble GRAS (generally recommended as safe) ingredient which is widely used in different industries such as food and beverage processing.…”

Characterisation of soluble aggregates from commercial whey protein concentrate suspensions: Effect of protein concentration, pH, and heat treatment conditions

“…The modification of the native structure of whey proteins by heat‐induced denaturation and aggregation can lead to the improvement or extension of their functional properties and thus increase their food applications (Guyomarc’h et al ; Joyce et al ; Rasouli et al ). Heat treatments of whey protein suspensions over certain temperatures (60–70 °C) produce the opening of the molecule tertiary structure, allowing the exhibition of hydrophobic sites and inducing the formation of aggregates.…”