Original scientific paper
Effects of κ-CN Glycosylation on Rennet Coagulation Properties of Milk in Simmental Cattle
Valentina Bonfatti
orcid.org/0000-0003-3970-5764
; Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell’Università 16, 35020 Legnaro, Italy
Roberta Rostellato
; Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell’Università 16, 35020 Legnaro, Italy
Gianluca Chiarot
; Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell’Università 16, 35020 Legnaro, Italy
Daniele Vicario
; Italian Simmental Cattle Breeders Association (ANAPRI), Via Nievo 19, 33100 Udine, Italy
Paolo Carnier
orcid.org/0000-0002-6009-6601
; Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell’Università 16, 35020 Legnaro, Italy
Abstract
Contents of casein fractions are known to affect coagulation properties and cheese yield of milk, but studies on the effects of κ-CN composition on variation of coagulation properties of milk are still very scarce. Effects exerted by κ-CN composition on variation of milk coagulation properties (MCP) were investigated using 2,084 individual milk samples of Simmental cows. Rennet coagulation time (RCT), and curd firmness (A30) were measured using a computerized renneting meter. Milk protein composition and genotypes at CSN2, CSN3 and BLG were obtained by reversed-phase HPLC. The percentage ratios of κ-CN (κCN%), of Glycosylated-κ-CN (G-κCN%), and Unglycosylated-κ-CN (U-κCN%) to total casein were measured. The degree of glycosylation (GD) was measured as the percentage ratio of glycosylated-κ-CN to total κ-CN. A difference of 1.7 min (corresponding to 0.37 SD of the trait) was observed for the average RCT of the two extreme classes of κCN% content. RCT decreased when κCN% and G-κCN% increased, whereas U-κCN% exhibited a slightly unfavourable effect on the onset of the coagulation process. A slight decrease of RCT was also observed for high GD, although this effect was less clear than that of G-κCN%. A favourable effect of κCN%, G-κCN% and GD on A30 was also detected.
Keywords
κ-CN; glycosylation; milk coagulation time; curd firmness; casein
Hrčak ID:
106897
URI
Publication date:
4.9.2013.
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