Variation in nutritionally relevant components in retail Jersey and Guernsey whole milk

• Published in: Food chemistry 2013-08, Vol.139 (1-4), p.540-548
• Main Authors: Stergiadis, S., Seal, C.J., Leifert, C., Eyre, M.D., Larsen, M.K., Butler, G.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cattle - classification; Cattle - metabolism; Fatty acid; Fatty Acids, Omega-3 - analysis; Fatty Acids, Omega-3 - metabolism; Female; Food industries; Fundamental and applied biological sciences. Psychology; Guernsey; Humans; Jersey; Milk; Milk - chemistry; Milk - metabolism; Milk and cheese industries. Ice creams; Milk Proteins - analysis; Milk Proteins - metabolism; Nutritive Value; Protein; Quality Control; Seasons; United Kingdom; α-Tocopherol
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2013.01.078

► Quality characteristics of retail Jersey and Guernsey milk and standard retail milk were compared. ► Seasonal and yearly changes in milk quality were compared at four sampling points over 2years. ► Some of the less desirable nutritional traits of Jersey and Guernsey milk were reduced in summer. ► n-3 PUFA in Jersey and Guernsey milk increased more from winter to summer than in standard milk. ► Interactions between breed and season were greater for the fatty acid than protein profiles of milk. This study investigates the quality of retail milk labelled as Jersey & Guernsey (JG) when compared with milk without breed specifications (NS) and repeatability of differences over seasons and years. 16 different brands of milk (4 Jersey & Guernsey, 12 non specified breed) were sampled over 2years on 4 occasions. JG milk was associated with both favourable traits for human health, such as the higher total protein, total casein, α-casein, β-casein, κ-casein and α-tocopherol contents, and unfavourable traits, such as the higher concentrations of saturated fat, C12:0, C14:0 and lower concentrations of monounsaturated fatty acids. In summer, JG milk had a higher omega-3:omega-6 ratio than had NS milk. Also, the relative increase in omega-3 fatty acids and α-tocopherol, from winter to summer, was greater in JG milk. The latter characteristic could be of use in breeding schemes and farming systems producing niche dairy products. Seasonality had a more marked impact on the fatty acid composition of JG milk than had NS milk, while the opposite was found for protein composition. Potential implication for the findings in human health, producers, industry and consumers are considered.