TY - JOUR

T1 - Impact of UHT treatment and storage on liquid infant formula

T2 - Complex structural changes uncovered by centrifugal field-flow fractionation with multi-angle light scattering

AU - Lund, Pernille

AU - Nielsen, Søren Bang

AU - Nielsen, Christian Fiil

AU - Ray, Colin A.

AU - Lund, Marianne N.

PY - 2021

Y1 - 2021

N2 - Protein modifications in liquid infant formula (IF) have been widely studied, but distinguishing between heat- and storage-induced structural changes remains challenging. A generic liquid IF was subjected to direct or indirect UHT treatment and stored at 40 °C up to 180 days. Colour and pH were monitored and structural changes were characterised by dynamic light scattering, SDS-PAGE and centrifugal field-flow fractionation (FFF) coupled with multi-angle light scattering (MALS) and UV detectors to evaluate whether heat-induced differences would level out during storage. Both direct- and indirect UHT treatment led to structural changes, where the higher heat load of the indirect UHT treatment caused more pronounced changes. Indications were that storage-induced changes in pH, browning and non-reducible cross-links were not dependent on UHT treatment. However, FFF-MALS-UV analysis allowed characterisation of complex aggregates, where structural changes continued to be most pronounced in indirect UHT treated samples, and different storage-induced aggregation behaviour was observed.

AB - Protein modifications in liquid infant formula (IF) have been widely studied, but distinguishing between heat- and storage-induced structural changes remains challenging. A generic liquid IF was subjected to direct or indirect UHT treatment and stored at 40 °C up to 180 days. Colour and pH were monitored and structural changes were characterised by dynamic light scattering, SDS-PAGE and centrifugal field-flow fractionation (FFF) coupled with multi-angle light scattering (MALS) and UV detectors to evaluate whether heat-induced differences would level out during storage. Both direct- and indirect UHT treatment led to structural changes, where the higher heat load of the indirect UHT treatment caused more pronounced changes. Indications were that storage-induced changes in pH, browning and non-reducible cross-links were not dependent on UHT treatment. However, FFF-MALS-UV analysis allowed characterisation of complex aggregates, where structural changes continued to be most pronounced in indirect UHT treated samples, and different storage-induced aggregation behaviour was observed.

KW - Aggregation

KW - Baby formula

KW - Browning

KW - Casein micelle

KW - Direct UHT

KW - Heating

KW - Indirect UHT

KW - Protein modification

KW - SDS-PAGE

KW - Whey protein

U2 - 10.1016/j.foodchem.2021.129145

DO - 10.1016/j.foodchem.2021.129145

M3 - Journal article

C2 - 33524693

AN - SCOPUS:85100037049

VL - 348

JO - Food Chemistry

JF - Food Chemistry

SN - 0308-8146

M1 - 129145

ER -