Quantification of αs1-Casein in Goat Milk from French-Alpine and Anglo-Nubian Breeds Using Reversed-Phase High Performance Liquid Chromatography

• Published in: Journal of dairy science 1991-10, Vol.74 (10), p.3303-3307
• Main Authors: Mora-Gutierrez, A., Kumosinski, T.F., Farrell, H.M.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Breeding; caprine; casein; Caseins - analysis; Chromatography, High Pressure Liquid; Electrophoresis, Polyacrylamide Gel; Female; Food industries; Fundamental and applied biological sciences. Psychology; Goats - genetics; Goats - physiology; high performance liquid chromatography; Lactation - genetics; Milk - analysis; Milk and cheese industries. Ice creams; reversed-phase
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(91)78516-0

Samples of isoelectrically precipitated goat casein from the milks of French-Alpine and Anglo-Nubian breeds were separated into four components in a single run by reversed-phase HPLC. The proportion of αs1-casein thus resolved was determined quantitatively. The method uses a reversed-phase C-4 column and a linear gradient from 30 to 50% acetonitrile in 30min with trifluoroacetic acid constant at .1%. Sodium dodecyl sulfate-PAGE was carried out to establish the identity of the isolated components. By a comparison with previously published results for caprine and bovine milk caseins, the four peaks were identified as κ-, αs2-, αs1-, and β- casein. Quantitative variations in the chromatographically resolved αs1-casein fraction of goat milk were evident. Some individual goat milks contained high levels of αs1-casein (2.70g/L), but others contained significantly low levels (.12 g/ L). There was no statistical difference in the overall means between breeds in αs1-casein composition, but cluster analysis statistics showed three distinct categories of αs1-producers: high, medium, and low. Interestingly, 6 of 15 French-Alpine goats and only one Anglo-Nubian goat fell into the “low” producer category (.38±.2g/L). Thus, expression of the αs1- component may be genetically regulated but may not be a breed-specific trait.