Effect of Controlled κ-Casein Hydrolysis on Rheological Properties of Acid Milk Gels

An experimental method based on the controlled chymosin-induced κ-casein hydrolysis of milk was proposed to modify micellar reactivity. Milk samples with a degree of κ-casein hydrolysis of 19, 35, and 51% were obtained. The physicochemical properties of partially converted casein micelles were deter...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of dairy science 2003-03, Vol.86 (3), p.704-711
Hauptverfasser: Gastaldi, E., Trial, N., Guillaume, C., Bourret, E., Gontard, N., Cuq, J.L.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:An experimental method based on the controlled chymosin-induced κ-casein hydrolysis of milk was proposed to modify micellar reactivity. Milk samples with a degree of κ-casein hydrolysis of 19, 35, and 51% were obtained. The physicochemical properties of partially converted casein micelles were determined. The net negative charge of casein micelles was reduced with increasing degree of κ-casein hydrolysis and a small but significant decrease in hydrodynamic diameter and micellar hydration were noted. Dynamic low amplitude oscillatory rheology was used to monitor the rheological properties of acid milk gels (GDL) made with partially chymosin-hydrolyzed milks in comparison with those of strictly acid and rennet gels. An increase in the gelation pH value was observed with increasing the degree of κ-casein hydrolysis. The moduli values (G′ and G″) reached 2h after the point of gel were, for all degrees of hydrolysis tested, significantly higher than those of strictly rennet and acid gels. Comparison of changes in ΔG′/Δt with time indicated differences in gel formation that could be related to the increased values of G′ obtained for acid gel made with chymosin-treated milk. At a given time after gelation (2h), increasing the degree of κ-casein hydrolysis in milk led also to an increase in the loss tangent and the serum holding capacity of acid milk gels suggesting a correlation between these two parameters.
ISSN:0022-0302
1525-3198
DOI:10.3168/jds.S0022-0302(03)73650-9