不同烟草品种烟籽油理化性质及脂肪酸和挥发性成分评价

本研究采用索氏提取法提取8个烟草品种的烟籽油,进行理化性质分析,并用气相色谱（GC）、气相色谱-质谱联用技术（GC-MS）分别测定烟籽油的脂肪酸组成和挥发性成分。结果表明,除皂化值和折光率外,8种烟籽油在酸价、比重、过氧化值及碘值中均差异显著,红大和NC89两个品种的酸价最低,保山4号的过氧化值最低,NC89的碘值最高,大竖把直把品种的比重最大,8个品种烟籽油的皂化值范围为176.13~190.81 mg·g^-1、折光率约为1.470,综合理化性质数据,品质较好的是Burley21,它的酸价、皂化值、比重、过氧化值、碘值及折光率分别是0.75 mg·g^-1、185.04 mg·g^-1、0.84 g·cm^-3、1.17%、1520.5 g·kg^-1及1.467 81。8个烟籽油品种的多不饱和脂肪酸含量均较高（785.99~965.99 mg·g^-1）,多不饱和脂肪酸/饱和脂肪酸（PUFA/SFA）值在5.61~6.60,亚油酸在8个品种测得的所有脂肪酸中均含量最高（772.41~944.20 mg·g^-1）。在8个品种的烟籽油中检测出棕榈酸甲酯、棕榈酸、亚油酸甲酯、油酸甲酯、亚油酸、己内酰胺和2,2'-亚甲基双-(4-甲基-6-叔丁基苯酚)7种挥发性物质,其中亚油酸含量最高,与脂肪酸含量测定结果具有一致性。比较脂肪酸及挥发性物质结果,云雪2号及Burley21两个品种较好。综合理化性质、脂肪酸与挥发性物质结果,Burley21是较为理想的烟籽油原料。

Evaluation of physicochemical properties,fatty acids and volatile components of different tobacco seed oils

In this study, the Soxhlet extraction method was used for extracting tobacco accessions. The physicochemical properties were measured, and the fatty acid composition and volatile components of tobacco seed oil were determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) for quality evalution. The results showed that there were significant differences in acid value, specific gravity, peroxide value and iodine value among eight tobacco seed oils, except saponification value and refractive index. Hongda and NC89 had the lowest acid value, Baoshan 4 showed the lowest peroxide value, the highest iodine value is NC89, and Dashubazhiba was with the highest specific gravity. Based on the performance of physical and chemical properties, the Burley21 has a better quality, whose acid value, saponification value, specific gravity, peroxide value, iodine value and refractive index were 0.75 mg·g^-1, 185.04 mg·g^-1, 0.84 g·cm^-3, 1.17%, 1 520.5 g·kg^-1 and 1.467 81, respectively. All the seed oil of eight different tobacco accessions were showed a high level of polyunsaturated fatty acids contents (785.99-965.99 mg·g^-1), and the polyunsaturated fatty acids/saturated fatty acids(PUFA/SFA) value ranged from 5.61 to 6.60. The linoleic acid content was the highest (772.41-944.20 mg·g^-1) among all the measured fatty acids. On the other hand, in total, we detected seven kinds of volatile substances, including palmitic acid methyl ester, methyl palmitic acid, linoleic acid, oleic acid, linoleic acid, methyl caprolactam, and 2, 2'-methylene double-(4-methyl-6-tertiary butyl phenol) from the seed oil. The composition and the content of volatile substances were highly consistent with the polyunsaturated fatty acids. In summary, considering the results of fatty acids and volatile substances, we found that Yunxue 2 and Burley21 showed better quality. Taken together, we concluded that the Burley21 is an ideal raw material for tobacco seed oil.