Modification of the sterol profile in milk through feeding

Abstract

The fortification of milk with phytosterols is an increasingly common practice to enhance the sterol profile and offer consumers potential health benefits. This study investigated whether cattle feed can influence the profile of phytosterols and cholesterol in the milk produced as an alternative to direct fortification of milk. Five experiments were performed using feeds commonly used by Australian dairy farmers and selected formulated rumen-protected feeds. Statistical significances were observed for some individual plant sterols and cholesterol in milk under these differing feeding regimens compared with the respective controls. In the case of the phytosterols, where the daily recommended consumption is typically 2 g per day, the total phytosterols were <0.12 mg/100 mL of milk. An experiment using a rumen-protected feed with high phytosterol levels suggested a decreased transfer of cholesterol to the milk by as much as 20%, although further work is required to confirm these preliminary results. Overall, the study suggests that different feeding practices have minimal effect on the resulting sterol profile of the milk.

Natural content of animal and plant sterols, alpha-tocopherol and fatty acid profile in sheep milk and cheese from mountain farming

“…Low quantities of stigmasterol were present in the analysed milk (0.03 mg 100 g -1 of milk) (Table 4) similarly to findings in cow milk (<0.02 mg 100 g -1 ) (Duong et al, 2019).…”

“…The amount of total plant sterols in the products we analyzed ranged from 9.89 mg 100 g -1 of fat in milk, to 16.67 mg 100 g -1 of fat in Pecorino cheese (Table 3), higher than the values reported in the literature for cow milk (3.42 mg 100 g -1 of fat) (calculated from Duong et al, 2019).…”

“…Milk campesterol (0.27 mg 100 g -1 of milk) and beta-sitosterol (0.14 mg 100 g -1 ) contents (Table 4) were in the range reported for cow milk (campesterol: 0.08-0.38 mg 100 g -1 of milk; beta-sitosterol : <0.02 and 5.3 mg 100 g -1 of milk) (Duong et al, 2019;Sadeghi et al, 2018), while brassicasterol (0.25 mg 100 g -1 of milk) was higher than in cow (<0.02 mg 100 g -1 of milk) (Duong et al, 2019).…”

“…Among the minor sterols of animal origin, the most represented in sheep milk is lanosterol (Goudjil et al, 2003), which has bioactive effects in humans (Zhao et al, 2015). Phytosterols, are also present in ruminant milk and appear to derive from the diet of the animals (Goudjil et al, 2003), however in dairy cow feeding the diet did not seem to change the plant sterol content in the milk (Duong et al, 2019). Phytosterols are produced by plants and have a chemical structure similar to cholesterol (Gylling et al, 2014).…”

Oxysterols: From redox bench to industry

“…Supplementing animal feed with antioxidants, namely vitamin E and linseed oil, has been shown to reduce total COPs in beef meat [ 133 ]. Similarly, milk produced by cows fed with feed fortified with oxidation-protective agents, such as vitamin E, polyunsaturated fatty acids (PUFA) or high phytosterol levels, has been shown to contain lower levels of cholesterol and/or total non-enzymatic COPs [ 134 , 135 ].…”