Insolubility of milk powder products – A minireview

Abstract

-In this paper, the formation of insolubility in milk powder is described, and the factors affecting the reaction are discussed. The zone in which casein proteins are most sensitive to heat is in the moisture range that occurs during spray drying. The rate of reaction has been determined and shows differences of orders of magnitude with the moisture content. The effect of chemical reagents on the extent of reaction gives insights into the chemical bonds that inhibit hydration. Information on the drying of casein products and individual proteins is used to infer that the withdrawal of moisture from casein proteins and the concentration of divalent cations during drying lead to alterations in the conformation of proteins that have an adverse effect on their rehydration during reconstitution. Further work to fully characterise these effects is required.spray drying / powder / casein / insolubility / kineticsRésumé -Insolubilité des poudres laitières -une mini-revue. L'apparition de l'insolubilité des poudres laitières est décrite et les facteurs affectant cette réaction sont discutés dans cet article. La zone dans laquelle les caséines sont les plus sensibles à la chaleur se situe dans la gamme d'humidité intervenant au cours du procédé de séchage par atomisation. La vitesse de réaction a été déterminée et montre des différences d'ordres de grandeur des taux d'humidité. L'effet des réactifs chimiques sur l'étendue de la réaction donne un aperçu des liaisons chimiques qui inhibent l'hydratation. On peut déduire de l'information obtenue sur le séchage des caséines et des protéines individuelles que l'élimination de l'humidité des caséines et la concentration en cations divalents au cours du séchage conduisent à des modifications de la conformation des protéines qui peuvent avoir des effets négatifs sur leur réhydratation au cours de la reconstitution des poudres. Un travail ultérieur est nécessaire pour caractériser complètement ces effets.séchage par atomisation / poudre / caséine / insolubilité / cinétique

Formation and structure of insoluble particles in reconstituted model infant formula powders

“…Protein insolubility is initiated by the unfolding of whey proteins followed by aggregation with casein (Baldwin, 2010;Sharma et al, 2012;Straatsma, Van Houwelingen, Steenbergen, & De Jong, 1999) and in fat-containing systems this results in formation of protein-bridged fat globule clusters (Singh & Ye, 2010). Based on the previous research (De Ruyck, 1991;McKenna et al, 1999;Mol, 1975;Ohba, Takahashi, & Igarashi, 1989) the formation of insoluble material is hypothesised to originate from heat and shear applied during spray drying resulting in changes in fat-protein interactions.…”

Physico-chemical, functional and rheological properties of milk protein concentrate 60 as affected by disodium phosphate addition, diafiltration and homogenization

“…Nitrogen solubility index (NSI); dispersability and heat stability of 32 commercial MPC powders were widely varied in the range of 27-87%; 38-100% and 0-42 min, respectively (Huppertz and Gazi 2015). Baldwin (2010) reported that poor solubility of MPC powders continued to be a problem by negatively affecting other functional properties.…”

“…During drying of SMP and WMP, lactose prevents protein-protein interaction as it acts as a mechanical spacer; forms hydrogen bonds with protein chains and also provides channel for absorption of water molecules within casein micelles during reconstitution process, resulting in better solubility (Baldwin 2010). Passage of lactose into permeate during UF treatment, minimizes retentates protection during drying; resulted in poor solubility of MPC powders.…”

“…Passage of lactose into permeate during UF treatment, minimizes retentates protection during drying; resulted in poor solubility of MPC powders. Insolubility reaction can take place either on the particle surface or between casein micelles, but detailed scientific data for the complete elucidation of insolubility development mechanism is still not clear (Baldwin 2010). Therefore, improving the solubility of MPC powders remains a key challenge to improve its functionality and uses.…”

Reconstitution properties of micellar casein powder: Effects of composition and storage

“…Poor reconstitutability of these powders is mainly due to slow release of casein micelles from the powder particle as it has been shown that the slowly solubilising material consists almost entirely of caseins, whereas the whey proteins, lactose and minerals are readily soluble (Anema et al, 2006;Havea, 2006;Mimouni et al, 2010a). Caseins are aggregated via non-covalent bonding (Anema et al, 2006;Baldwin, 2010;Havea, 2006). Microstructural analysis shows that with increased storage time the casein micelles increasingly interact with each other, especially on the surface of the powder particle, leading to "skin" formation, slowing down the release of the casein micelles from the dispersed powder particles (Mimouni, Deeth, Whittaker, Gidley, & Bhandari, 2010b).…”