Selective and time-dependent transfer of herb-derived terpenes into cow milk without sensory impacts

Herb supplementation is increasingly researched in dairy nutrition, yet the availability of comparative data on the short-term transfer kinetics of herb-derived terpenes into milk and their sensory relevance remains limited. The major objective of the study was to reveal the short-term effects of feed supplementation (i.e., oregano, basil, thyme, rosemary, and yarrow) on milk's volatile compound composition, in accordance with the former findings establishing rapid transfer of terpenes from essential oils to dairy cow milk. Thirty-six Holstein-Friesian cows were assigned to 1 control and 5 herb-supplemented groups. Milk samples were collected at 0, 8, 16, and 24 h following bolus administration and analyzed on raw milk samples by GC-MS. Customer test was performed by 30 untrained panelists on pasteurized milk samples. Transfer of herb-derived terpenes was found to be compound- and plant-specific. Apolar monoterpenes, particularly p-cymene and α-pinene, were most consistently detected, with peak concentrations occurring at 16 to 24 h post-administration. Maximum concentrations ranged from trace levels to 1.28 ng/g (α-pinene, rosemary group). Polar phenolic terpenes (thymol, carvacrol, eugenol) showed restricted or delayed transfer despite high abundance in herbs. No significant differences were observed in pasteurized milk color, aroma, flavor, or texture across all the treatments. Herb-derived terpenes can be transferred into milk within hours; however, concentrations remain below the sensory thresholds. The study demonstrates the feasibility of herb supplementation without compromising pasteurized milk sensory quality and highlights physicochemical constraints governing feed-to-milk transfer.