Heat‐induced coagulation of whole milk by high levels of calcium chloride

Abstract

This study investigated the interaction of calcium ions and milk proteins during heat‐induced coagulation of milk. Addition of 20–200 mM calcium chloride to milk caused coagulation on heating to 70 °C. Preheating milk at 90 °C for 10 min or ultra‐high temperature treatment at 140 °C for 6 s increased the sensitivity of milk proteins to coagulation. The former treatment was more effective than the latter in coagulating proteins. A maximum of 98% of the protein in milk preheated at 90 °C for 10 min was coagulated by 50 mM added calcium chloride at 70 °C with holding for 5 min.

Rheological and physical properties of camel and cow milk gels enriched with phosphate and calcium during acid-induced gelation

“…As observed, shorter gelation time and higher gelation rate were observed for camel milk gels with added calcium (20 mM) since a significant decrease of gelation time (p \ 0.05) and an increase in the gelation rate compared with control camel milk gels were observed with added CaCl 2 at 20 mM. These modifications in the gelation time and gelation rate with added CaCl 2 could be attributed to the increase of ionic calcium concentration inducing: (1) a pH decrease resulting from the negative charge decrease at the surface of caseins; and (2) the formation of more bridges between casein proteins and calcium (Koutina et al 2016;Ramasubramanian et al 2012).…”

Textural and sensory properties of a calcium-induced milk gel

“…This increase is related to the increase in the number and strength of cross-linking of the milk proteins by calcium ions (Lee and Marshall, 1984). Calcium was not added at levels higher than 20 mM as these cause the gel strength to increase so much that coagulation occurs with expulsion of whey (Ramasubramanian et al, 2012).…”

Calcium induced skim-milk gelation during heating as affected by pH

“…The addition of relatively high amounts of calcium salts will increase the ionic calcium concentration and decrease the pH which in combination with structural changes in whey proteins during heat treatment will lead to milk coagulation (Omoarukhe et al 2010;Ramasubramanian et al 2012;Vasbinder and de Kruif 2003). Still, the effect of pH on calcium gel formation under heat treatment is not well documented.…”

“…Heat processing of calcium supplemented milk was found to lead to milk coagulation and to formation of a novel type of gel for which the term "calcium-milk coagulum" was coined (Ramasubramanian et al 2012;Ramasubramanian et al 2014). The addition of relatively high amounts of calcium salts will increase the ionic calcium concentration and decrease the pH which in combination with structural changes in whey proteins during heat treatment will lead to milk coagulation (Omoarukhe et al 2010;Ramasubramanian et al 2012;Vasbinder and de Kruif 2003).…”