Department of Food Science, Aarhus University, Tjele, DK-8830, Denmark.
J Dairy Sci. 2013 Jul;96(7):4235-41. doi: 10.3168/jds.2012-6502. Epub 2013 Apr 28.
The objective of this study was to investigate the transfer of volatile terpenes from caraway seed and oregano plant essential oils into cow's milk through respiratory and gastrointestinal exposure. Essential oils have potential applications as feed additives because of their antimicrobial properties, but very little work exists on the transfer of their volatile compounds into milk. Lactating Danish Holstein cows with duodenum cannula were used. Gastrointestinal exposure was facilitated by infusing the essential oils, mixed with deodorized sesame oil, into the duodenum cannula. Two levels were tested for each essential oil. Respiratory exposure was facilitated by placing the animal in a chamber together with a sponge soaked in the essential oils. All exposures were spread over 9h. Milk samples were collected immediately before and after exposure, as well as the next morning. Twelve monoterpenes and 2 sesquiterpenes were analyzed in essential oils and in milk samples using dynamic headspace sampling and gas chromatography-mass spectrometry. In the essential oils, almost all of the terpenes were detected in both essential oils at various levels. For caraway, the monoterpenes limonene, carvone, and carvacrol were most abundant; in oregano, the monoterpenes carvacrol and ρ-cymene were most abundant. For almost all treatments, an immediate effect was detected in milk, whereas little or no effect was detected in milk the following day. This suggests that the transfer into milk of these volatile terpenes is fast, and that the milk will not be influenced when treatment is discontinued. Principal component analysis was used to elucidate the effect of the treatments on the terpene profile of the milk. Terpene content for treatment milk samples was characterized by the same terpenes found in the treatment essential oil used for that animal, regardless of pathway of exposure. The terpenes appear to be transferred unaltered into the milk, regardless of the pathway of exposure. Volatile terpenes in essential oils, which could influence milk flavor, are transferred into milk via both gastrointestinal and respiratory exposure.
本研究旨在通过呼吸和胃肠道暴露，研究挥发性萜烯从葛缕子籽和牛至植物精油转移到牛奶中的情况。由于具有抗菌特性，精油具有作为饲料添加剂的应用潜力，但关于其挥发性化合物转移到牛奶中的研究非常少。使用了带有十二指肠套管的泌乳丹麦荷斯坦奶牛。通过将精油与脱臭芝麻油混合并注入十二指肠套管来促进胃肠道暴露。对每种精油都测试了两个水平。通过将动物放在一个充满浸有精油的海绵的腔室中促进呼吸暴露。所有暴露都持续 9 小时。在暴露前后以及第二天早上立即采集牛奶样本。使用动态顶空采样和气相色谱-质谱法分析精油和牛奶样本中的 12 种单萜和 2 种倍半萜。在精油中，几乎所有萜烯都以不同水平存在于两种精油中。对于葛缕子，单萜烯柠檬烯、香芹酮和香芹酚含量最丰富；对于牛至，单萜烯香芹酚和 ρ- 侧柏烯含量最丰富。对于几乎所有处理，牛奶中都立即检测到影响，而第二天牛奶中几乎没有或没有检测到影响。这表明这些挥发性萜烯快速转移到牛奶中，并且当处理停止时，牛奶不会受到影响。主成分分析用于阐明处理对牛奶中萜烯谱的影响。处理牛奶样品的萜烯含量由用于该动物的处理精油中发现的相同萜烯来表征，而不管暴露途径如何。萜烯似乎未改变地转移到牛奶中，而不管暴露途径如何。可能影响牛奶风味的精油中的挥发性萜烯通过胃肠道和呼吸暴露都转移到牛奶中。
