Chemistry Department, Seattle University , 901 12th Avenue, Seattle, Washington 98122-1090, United States.
J Agric Food Chem. 2014 Oct 22;62(42):10222-9. doi: 10.1021/jf5034416. Epub 2014 Oct 13.
Potato taste defect (PTD) is a flavor defect in East African coffee associated with Antestiopsis orbitalis feeding and 3-isopropyl-2-methoxypyrazine (IPMP) in the coffee. To elucidate the manifestation of PTD, surface and interior volatile compounds of PTD and non-PTD green coffees were sampled by headspace solid phase microextraction and analyzed by gas chromatography mass spectrometry. Principal component analysis of the chromatographic data revealed a profile of surface volatiles distinguishing PTD from non-PTD coffees dominated by tridecane, dodecane, and tetradecane. While not detected in surface volatiles, IPMP was found in interior volatiles of PTD coffee. Desiccated antestia bugs were analyzed by GCMS, revealing that the three most prevalent volatiles were tridecane, dodecane, and tetradecane, as was found in the surface profile PTD coffee. Coffee having visible insect damage exhibited both a PTD surface volatile profile and IPMP in interior volatiles, supporting the hypothesis linking antestia bug feeding activity with PTD profile compounds on the surface and IPMP in the interior of the beans.
土豆味缺陷（PTD）是东非咖啡的一种风味缺陷，与 Antestiopsis orbitalis 的取食和咖啡中的 3-异丙基-2-甲氧基吡嗪（IPMP）有关。为了阐明 PTD 的表现形式，通过顶空固相微萃取对 PTD 和非 PTD 生豆的表面和内部挥发性化合物进行了采样，并通过气相色谱-质谱法进行了分析。色谱数据的主成分分析显示，PTD 生豆与非 PTD 生豆的表面挥发性化合物图谱不同，主要由十三烷、十二烷和十四烷组成。虽然在表面挥发物中未检测到，但在 PTD 咖啡的内部挥发物中发现了 IPMP。对干燥的 Antestia 虫进行 GCMS 分析，发现三种最常见的挥发性化合物为十三烷、十二烷和十四烷，与 PTD 咖啡的表面图谱中发现的一致。可见昆虫损伤的咖啡既表现出 PTD 表面挥发性化合物图谱，也表现出内部 IPMP，这支持了 Antestia 虫取食活动与豆表面 PTD 特征化合物和豆内 IPMP 有关的假设。
