TY - JOUR
T1 - Critical phosphate salt concentrations leading to altered micellar casein structures and functional intermediates
AU - Saricay, Y.
AU - Hettiarachchi, C. A.
AU - Culler, M. D.
AU - Harte, F. M.
N1 - Funding Information:
This research was mainly funded by the National Dairy Council (Chicago, IL) through the project “Prototype to study the effect of ionic environments on casein micelle integrity.” The work was also partially supported by the USDA National Institute of Food and Agriculture Federal Appropriations under the project PEN04565 and accession number 1002916. The authors appreciate Grace Lewis (Department of Food Science, Pennsylvania State University) for her assistance with characterization of MC powder.
Publisher Copyright:
© 2019 American Dairy Science Association
PY - 2019/8
Y1 - 2019/8
N2 - We investigated the effect of different phosphate salts on the structural integrity of micellar casein (MC) at pH 7.0. With the increase of salt concentration, a reduction in turbidity was observed for the MC solutions, and it was modeled using an exponential decay function. The inflection point of the model was defined as the first critical salt concentration (C*), and it is suggested that the salt concentration initiates the disintegration of MC. For linear polyphosphates, C* decreased with the number of phosphate groups. Apparent viscosity (ηapp) of MC solutions increased with the increase of salt concentration, and they recorded a peak while the turbidity decreased to a minimum. The salt concentration that resulted in the highest ηapp was identified as the second critical salt concentration (C**). It is hypothesized that the interactions among protein species present in the mixtures are at an optimum state at C**. Both C* and C** were found to be dependent on the MC concentration. The work presented herein supports an understanding of the concentration effect of phosphate salts on MC for structuring dairy products.
AB - We investigated the effect of different phosphate salts on the structural integrity of micellar casein (MC) at pH 7.0. With the increase of salt concentration, a reduction in turbidity was observed for the MC solutions, and it was modeled using an exponential decay function. The inflection point of the model was defined as the first critical salt concentration (C*), and it is suggested that the salt concentration initiates the disintegration of MC. For linear polyphosphates, C* decreased with the number of phosphate groups. Apparent viscosity (ηapp) of MC solutions increased with the increase of salt concentration, and they recorded a peak while the turbidity decreased to a minimum. The salt concentration that resulted in the highest ηapp was identified as the second critical salt concentration (C**). It is hypothesized that the interactions among protein species present in the mixtures are at an optimum state at C**. Both C* and C** were found to be dependent on the MC concentration. The work presented herein supports an understanding of the concentration effect of phosphate salts on MC for structuring dairy products.
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U2 - 10.3168/jds.2018-15746
DO - 10.3168/jds.2018-15746
M3 - Article
C2 - 31178183
AN - SCOPUS:85066810147
SN - 0022-0302
VL - 102
SP - 6820
EP - 6829
JO - Journal of Dairy Science
JF - Journal of Dairy Science
IS - 8
ER -