焙炒条件对油菜籽中多环芳烃含量影响的研究

摘要

对油菜籽进行不同条件的焙炒,检测其中多环芳烃(PAHs)含量的变化,研究浓香菜籽油生产中焙炒条件对PAHs含量的影响.结果表明:随着焙炒温度升高(160、180、200、220、240、260 ℃)和焙炒时间延长(10、20、30、40、50、60 min),油菜籽中PAHs含量呈明显的上升趋势;在40 min的焙炒时间内,随温度升高,苯并[a]芘(BaP)、4 种多环芳烃(PAH4)、16种多环芳烃(PAH16)含量增幅的差异不显著,超过40 min之后,含量增幅的差异性突显;在260 ℃、60 min的极限试验条件下,油菜籽中BaP、PAH4、PAH16含量分别从0.15、5.80、30.89 μg/kg增加至3.53、21.95、186.75 μg/kg;采用160 ℃、30 min的焙炒条件,油菜籽中BaP、PAH4、PAH16含量分别增加至0.78、8.30、70.58 μg/kg,BaP和PAH4含量均未超出欧盟限量(2 μg/kg和10 μg/kg),同时菜籽油也呈现较好的香味;此外,焙炒过程轻质多环芳烃(LPAHs)含量增幅远大于重质多环芳烃(HPAHs).%The rapeseed was roasted under different conditions and the content of polycyclic aromatic hydrocarbons (PAHs) was determined. The effects of roasting conditions on PAHs content in the production of fragrant rapeseed oil were studied. The results indicated that the PAHs content in rapeseed increased significantly with the increase of roasting temperature (160, 180, 200, 220, 240, 260 ℃) and roasting time (10, 20, 30, 40, 50 and 60min). The difference between the increase of Benzo [a] pyrene (BaP), 4 kinds of polycyclic aromatic hydrocarbons(PAH4) and 15 kinds of polycyclic aromatic hydrocarbons (PAH16) was not significant with the increase of temperature when roasting below 40 min, while the difference of the increase of these contents increased rapidly after roasting 40 min. Under the extreme tested conditions of 260℃ and 60 min, the contents of BaP, PAH4 and PAH16increased from 0.15 ,5.80 and 30.89 μg/kg to 3.53,21.95 and 186.75μg/kg, respectively. The contents of BaP, PAH4 and PAH16 in rapeseed increased to 0.78, 8.30 and 70.58 μg/kg respectively under the conditions of 160℃ and 30 min. Besides, the contents of BaP and PAH4 in the rapeseed hadn't exceed the EU limit of 2 μg/kg and 10 μg/kg, respectively. Meanwhile, rapeseed oil also showed good fragrance. In addition, the content of light PAHs in roasting process increased much faster than those of heavy PAHs.