Analysis of volatile compounds in beef fat by dynamic-headspace solid-phase microextraction combined with gas chromatography-mass spectrometry.
A solid-phase microextraction (SPME) technique has been applied to the determination of the volatile compounds, including diterpenoids and lactones, in cooked beef fat. The ability of static-headspace SPME to extract lactones was disappointing, regardless of the type of SPME fiber or the temperature used. Dynamic-headspace SPME extraction with 50-/30-microm divinylbenzene-Carboxen on a polydimethylsiloxane fiber at 100 degrees C, by contrast, enabled the analysis of volatiles, including delta-lactones, gamma-lactones, and diterpenoids, with 50-/30-microm divinylbenzene-Carboxen on a polydimethylsiloxane fiber at 100 degrees C. Fifty-three compounds were identified from only 0.20 g of rendered beef fat, and 76% of these showed reliable peak size repeatability: the coefficient of variation was less than 10% on the total ion chromatograms obtained from gas chromatography-mass spectrometry (GC-MS) analysis. Some lactones showed higher CV values (>10%), but single-ion mode GC-MS analysis reduced them to 10% or less. In a study of beef samples available to the Japanese market, our analytical procedure revealed significantly higher levels of 1-hexanol, octadecane, ethyl tetradecanoate, gamma-nonalactone, but lower levels of delta-decalactone, delta-dodecalactone, and neophytadiene, in Japanese Black cattle than in beef imported from Australia.
Watanabe
A
A
Grazing and Meat Production Research Team, Tohoku National Agricultural Research Center, Morioka, Iwate, 020-0198, Japan. akiraw@affrc.go.jp
Ueda
Y
Y
Higuchi
M
M
Shiba
N
N
D000818:Animals; D002417:Cattle; D004224:Diterpenes / Q000032:analysis; D005232:Fatty Acids, Volatile / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D007783:Lactones / Q000032:analysis; D008460:Meat / Q000032:analysis; D009812:Odorants / Q000032:analysis; D052617:Solid Phase Microextraction / Q000379:methods*; D013045:Species Specificity; D013696:Temperature; D014835:Volatilization
D004224:Diterpenes; D005232:Fatty Acids, Volatile; D007783:Lactones