Effect of cysteine addition and heat treatment on the properties and microstructure of a calcium-induced whey protein cold-set gel

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dc.contributor.authorLavoisier, Anais
dc.contributor.authorVilgis, Thomas A.
dc.contributor.authorAguilera, Jose Miguel
dc.date.accessioned2025-01-23T21:10:05Z
dc.date.available2025-01-23T21:10:05Z
dc.date.issued2019
dc.description.abstractA model gel of whey protein isolate (WPI) was prepared by cold gelation with calcium. This system was modified by the addition of free cysteine residues (Cys) at different steps of the process. The WPI cold-set gels obtained were then subjected to heat treatment at 90 degrees C. First, the effect of Cys addition on the heat-induced aggregation of WPI was studied through Atomic Force Microscopy (AFM) and infrared spectroscopy (ATR-FTIR), while Cys' effect on cold gelation was observed by AFM, Confocal Laser Scanning Microscopy (CLSM) and oscillatory rheology (amplitude sweeps). The impact of heating on the microstructure and the viscoelastic properties of the WPI cold-set gels were finally investigated through several techniques, including DSC, ATR-FTIR, CLSM, cryo-SEM, and rheological measurements (temperature sweeps). When added during the first step of cold gelation, Cys modified heat-induced aggregation of WPI, resulting in the formation of a denser gel network with a fractal dimension (Df) of 2.8. However, the addition of Cys during the second step of cold gelation led to the formation of highly branched clusters of WPI and a looser gel network was observed (Df = 2.4). In this regard, the use and limitations of oscillatory rheology and the "Kraus model" to determine the Df of WPI cold-set gels was discussed. The viscoelastic properties and the microstructure of the WPI cold-set gels were irreversibly modified by heating. Gels were stiffer, more brittle, and coarser after heat treatment. New disulfide bonds and calcium bridges formed, as well as H-bonded beta-sheets, all contributing to the formation of the final gel network structure.
dc.fuente.origenWOS
dc.identifier.doi10.1016/j.crfs.2019.10.001
dc.identifier.eissn2665-9271
dc.identifier.urihttps://doi.org/10.1016/j.crfs.2019.10.001
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/100840
dc.identifier.wosidWOS:000658375900006
dc.language.isoen
dc.pagina.final42
dc.pagina.inicio31
dc.revistaCurrent research in food science
dc.rightsacceso restringido
dc.subjectProtein network
dc.subjectCold gelation
dc.subjectFractal dimension
dc.subjectAtomic force microscopy
dc.subjectCryo-SEM
dc.subjectRheology
dc.subject.ods03 Good Health and Well-being
dc.subject.odspa03 Salud y bienestar
dc.titleEffect of cysteine addition and heat treatment on the properties and microstructure of a calcium-induced whey protein cold-set gel
dc.typeartículo
dc.volumen1
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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