Survey of the fatty acid composition of retail milk differing in label claims based on production management practices

Abstract

Consumers are becoming increasingly health conscious, and food product choices have expanded. Choices in the dairy case include fluid milk labeled according to production management practices. Such labeling practices may be misunderstood and perceived by consumers to reflect differences in the quality or nutritional content of milk. Our objective was to investigate nutritional differences in specialty labeled milk, specifically to compare the fatty acid (FA) composition of conventional milk with milk labeled as recombinant bST (rbST)-free or organic. The retail milk samples (n=292) obtained from the 48 contiguous states of the United States represented the consumer supply of pasteurized, homogenized milk of 3 milk types: conventionally produced milk with no specialty labeling, milk labeled rbST-free, and milk labeled organic. We found no statistical differences in the FA composition of conventional and rbST-free milk; however, these 2 groups were statistically different from organic milk for several FA. When measuring FA as a percentage of total FA, organic milk was higher in saturated FA (65.9 vs. 62.8%) and lower in monounsaturated FA (26.8 vs. 29.7%) and polyunsaturated FA (4.3 vs. 4.8%) compared with the average of conventional and rbST-free retail milk samples. Likewise, among bioactive FA compared as a percentage of total FA, organic milk was slightly lower in trans 18:1 FA (2.8 vs. 3.1%) and higher in n-3 FA (0.82 vs. 0.50%) and conjugated linoleic acid (0.70 vs. 0.57%). From a public health perspective, the direction for some of these differences would be considered desirable and for others would be considered undesirable; however, without exception, the magnitudes of the differences in milk FA composition among milk label types were minor and of no physiological importance when considering public health or dietary recommendations. Overall, when data from our analysis of FA composition of conventional milk and milk labeled rbST-free or organic were combined with previous analytical comparisons of the quality and composition of these retail milk samples, results established that there were no meaningful differences that would affect public health and that all milks were similar in nutritional quality and wholesomeness.

A comparative study of the fatty acid profiles in commercial sheep cheeses

“…PC1 consisted of the typical FA that can be found in the milk of small ruminants (C8:0 and C10:0) (Partidário et al, 2008) whereas C14:1c9 and C16:1c9 are usually detected in the milk and cheeses of cows (O'Donnell et al, 2010). Figure 1 shows a clear difference among animal species particularly between Groups I and II.…”

Quality of cows' milk from organic and conventional farming

“…The lower milk yield of these cows had a positive impact on the higher level of vitamins A, E, and D 3 as well as on the beneficial fatty acids content compared to the conventional group. Butler et al (2009Butler et al ( , 2011a, Prandini et al (2009), O'Donnell et al (2010, and Popović- Vranješ et al (2011) show the positive effect of organic farming residing in increasing the content of n-3 PUFA (as a-linolenic acid), CLA, vitamin A, and antioxidants (a-tocopherol, lutein, zeaxanthin, and β-carotene) in milk; substances that are generally considered beneficial to health (Halliwell 1996;McGuire & McGuire 1999;Lemaitre et al 2003).…”

Nutritionally Desirable Fatty Acids Including Cla of Cow's Milk Fat Explained by Animal and Feed Factors

“…However, previous studies found that, compared to grazing (Elgersma, 2015) or organic farming conditions (O'Donnell et al, 2010), partial feeding of housed dairy cows with fresh forage had only a limited effect on the proportion of nutritionally desirable FA in milk fat (Leiber et al, 2005). This could explain the low level of variation in oleic acid (6 %) and the group of monounsaturated FA (5 %).…”