Acidification chimique directe du lait : corrélations entre la mobilité du matériel micellaire et les micro et macrostructures des laits acidifiés

Abstract

Direct chemical acidification of milk: correlation between the mobility of micellar material and the macro and microstructures of acidified milk.Direct addition of lactic acid was used to follow the behaviour of reconstituted skimmed milk during a chemical acidification. The mobility of the micellar materials: minerals and caseins, was correlated with the change in a range of physicochemical parameters such as buffering capacity and conductivity. It was hypothesized that, for a given pH, the transformations that emerge within milk would be dependent on the biochemical state of: the added lactic acid; the micellar minerals; and of some of the functional groups of caseins. Determination of rheological state equations, calculation of storage and loss moduli and visualization by Scanning Electron Microscopy, allowed the hypothesis to be consolidated and showed the existence of three characteristic points around pH 5.8, 5.4 and 5.0. These results permitted some specificities of rapid and direct chemical acidification to be deduced and allowed their comparison with the situation in slow biological acidification.

Camel Milk as Adjuvant to Treat Alloxan Diabetes: Effect of Heat Treatment on this Property

“…Also some previous study [26,27] reported that heat treatment of camel milk allowed to a demineralization of the caseins micelle and to an increase of soluble Ca concentrations.…”

Impacts of Flow Rate and Pulsed Electric Field Current Mode on Protein Fouling Formation during Bipolar Membrane Electroacidification of Skim Milk

“…Indeed, with decrease of pH, protein-bounded calcium (or magnesium) phosphates (or citrates) compounds convert to the soluble ionic form and remain in the whey fraction of milk [ 23 ]. Numerous papers proved the fact that the decrease in pH of milk leads to dissolving colloidal calcium phosphate and small amounts of magnesium [ 24 , 25 , 26 ] and causes the dissociation of casein from micelles [ 27 ]. Milk pH decreased in a similar way to the one observed previously by Bazinet et al [ 28 ] and Masson et al [ 29 ] but with a different cell design (effective surface area of 100 cm 2 ).…”