Abstract
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.
Original language | English |
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Article number | 129145 |
Journal | Food Chemistry |
Volume | 348 |
Number of pages | 10 |
ISSN | 0308-8146 |
DOIs | |
Publication status | Published - 2021 |
Keywords
- Aggregation
- Baby formula
- Browning
- Casein micelle
- Direct UHT
- Heating
- Indirect UHT
- Protein modification
- SDS-PAGE
- Whey protein