The Aroma of Goat Milk: Seasonal Effects and Changes through Heat Treatment

• Published in: Journal of agricultural and food chemistry Vol. 62; no. 49; pp. 11805 - 11817
• Main Authors: Siefarth, Caroline, Buettner, Andrea
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 10.12.2014; American Chemical Society, Books and Journals Division
• Subjects: Adult; Animals; Chromatography, Gas; coumarin; farms; Female; flavor compounds; Flavoring Agents - chemistry; Food Handling - methods; gas chromatography; goat milk; Goats; heat treatment; Hot Temperature; Humans; Male; milk; Milk - chemistry; odor compounds; Odorants - analysis; odors; Olfactometry; raw milk; seasonal variation; Seasons; sensory evaluation; summer; Taste; winter; Young Adult; two-dimensional gas chromatography/olfactometry (2D-GC/O); aroma extract dilution analysis (AEDA); mass spectrometry; fatty acids; aroma profile analysis (APA); retention indices
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf5040724

Goat milk was characterized and analyzed by human sensory evaluation and gas chromatography/olfactometry (GC/O). Most potent odor-active compounds were determined in (a) raw goat’s milk from two different seasons and (b) heated goat’s milk after different treatment intensities. A trained panel found sensorial differences between winter and summer milks (seasonal effect) and milks from different farms (farm-specific effect). A total of 54 odor-active compounds with flavor dilution (FD) factors ≥8 were detected of which 42 odorants were identified. 4-Ethyloctanoic acid, 3-methylindole (skatol) and one unknown compound (RI 2715) showed highest intensities in all raw milks. With heat treatment, goat-like, stable-like, and (cooked) milk-like odor characteristics decreased while caramel-like or vanilla-like notes increased. In total, 66 odor-active compounds were detected in heated goat milks (FD ≥ 8). To the best of our knowledge, only 16 of the 42 identified odorants were reported before in raw goat’s milk. Additionally, for the first time the presence of 1-benzopyran-2-one (coumarin) could be confirmed in ruminant milk.