TY - JOUR

T1 - Physical and colloidal stability of conventional and micronised calcium citrate ingredient powders in the formulation of infant nutritional products

AU - France, Thomas C.

AU - Barone, Giovanni

AU - O'Regan, Jonathan

AU - Kelly, Alan L.

AU - O'Mahony, James A.

N1 - Funding Information: The authors would like to acknowledge Nestlé for providing financial support and supplying ingredients for this study, Fanyu Meng for her help with Turbiscan analysis, and Ryan Hazlett and the Department of Anatomy and Neuroscience Imaging Centre, BioSciences Institute, University College Cork, for assistance in preparing and imaging specimens for this research. Technical assistance from Dr Abina Crean and Dr Faisal Walid (School of Pharmacy, University College Cork) with surface area analysis is also appreciated. Publisher Copyright: © 2020 Elsevier B.V.

PY - 2020/10

Y1 - 2020/10

N2 - The fortification of food systems with calcium remains difficult; one challenge is to maintain the colloidal stability of insoluble calcium salts during processing and shelf life. Particle size reduction of insoluble salts may result in improved product stability. In this study, insoluble calcium citrate in two different particle sizes, conventional calcium citrate and micronised calcium citrate, were first evaluated in terms of physical and bulk handling properties, followed by protein adsorption and colloidal stability when dispersed in two dairy-based nutritional beverages differing in composition, i.e. infant milk formula stage 1 and 3. Particle size distribution analysis showed micronised calcium citrate (volume-weighted diameter = 5.10 μm) to have significantly smaller (p < 0.05) particle size than conventional calcium citrate (volume-weighted diameter = 88.2 μm). The adsorption of dairy proteins onto particles of calcium citrate resulted in caseins having greater affinity for both salts, followed by β-lactoglobulin. The smaller particle size of the micronised citrate resulted in higher affinity for casein and greater colloidal stability when dispersed in both infant milk formula solutions compared to conventional calcium salts. The results of this study provide knowledge on the application of micronised insoluble calcium salts in the fortification of nutritional dairy-based products.

AB - The fortification of food systems with calcium remains difficult; one challenge is to maintain the colloidal stability of insoluble calcium salts during processing and shelf life. Particle size reduction of insoluble salts may result in improved product stability. In this study, insoluble calcium citrate in two different particle sizes, conventional calcium citrate and micronised calcium citrate, were first evaluated in terms of physical and bulk handling properties, followed by protein adsorption and colloidal stability when dispersed in two dairy-based nutritional beverages differing in composition, i.e. infant milk formula stage 1 and 3. Particle size distribution analysis showed micronised calcium citrate (volume-weighted diameter = 5.10 μm) to have significantly smaller (p < 0.05) particle size than conventional calcium citrate (volume-weighted diameter = 88.2 μm). The adsorption of dairy proteins onto particles of calcium citrate resulted in caseins having greater affinity for both salts, followed by β-lactoglobulin. The smaller particle size of the micronised citrate resulted in higher affinity for casein and greater colloidal stability when dispersed in both infant milk formula solutions compared to conventional calcium salts. The results of this study provide knowledge on the application of micronised insoluble calcium salts in the fortification of nutritional dairy-based products.

KW - Calcium citrate

KW - Colloidal stability

KW - Flowability

KW - Infant formula

KW - Micronised

KW - Microstructure

KW - Protein adsorption

UR - http://www.scopus.com/inward/record.url?scp=85087201570&partnerID=8YFLogxK

U2 - 10.1016/j.colsurfb.2020.111125

DO - 10.1016/j.colsurfb.2020.111125

M3 - Journal article

C2 - 32622256

AN - SCOPUS:85087201570

VL - 194

JO - Colloids and Surfaces B: Biointerfaces

JF - Colloids and Surfaces B: Biointerfaces

SN - 0927-7765

M1 - 111125

ER -