浓香菜籽油在不同加工单元下多环芳烃和风味品质的变化规律

Effects of Processing on Polycyclic Aromatic Hydrocarbon Content and Flavor Quality of Strongly Flavored Rapeseed Oil

摘要:

分析了炒籽、压榨和脱胶等单元下油菜籽和油中多环芳烃的含量，明确了多环芳烃在浓香菜籽油3个加工单元中的迁移规律。在此基础上，考查了炒籽升温速率和脱胶单元对浓香菜籽油中多环芳烃形成和风味品质的影响。结果显示，炒籽和压榨单元均造成油菜籽及菜籽油中多环芳烃含量增加，炒籽后的油菜籽中苯并[a]芘、PAH4和EPA16含量分别增加0.40、3.79和10.51 μg/kg。脱胶单元使菜籽油中多环芳烃含量降低，其中轻质PAHs含量减少7.96 μg/kg。炒籽升温速率对浓香菜籽油中多环芳烃含量具有显著影响（P<0.05）。高升温速率下浓香菜籽油中苯并[a]芘、PAH4和EPA16含量分别为0.91、7.18和40.92 μg/kg；低升温速率下样品含量分别为0.38、3.21和27.99 μg/kg。炒籽升温速率对浓香菜籽油中多酚、生育酚和甾醇含量，以及挥发性化合物种类和含量影响不显著（P>0.05）。脱胶处理后，菜籽油中酸价下降0.45 mg/g，过氧化值增加0.49 mmol/kg；菜籽油L*和b*明显提升，a*降低；菜籽油中脂质氧化产物和美拉德反应产物含量分别降低31.19%和53.05%。研究结果可为浓香菜籽油生产中工艺参数优化提供有价值的参考。

Abstract:

The contents of polycyclic aromatic hydrocarbons (PAHs) in rapeseed and rapeseed oil after processing activities such as seed frying, squeezing, and degumming were studied and the migration patterns of PAHs investigated. The effects of seed frying heating rate and the influences of degumming on the formation of PAHs and the flavor quality of rapeseed oil were determined. Results indicated that the PAH content of rapeseeds and rapeseed oil increased during seed frying and squeezing. The benzo[a]pyrene, PAH4, and EPA16 contents of rapeseeds increased by 0.40, 3.79, and 10.51 μg/kg after frying, respectively, whereas PAH contents was reduced by degumming. In particular, the light PAH content decreased by 7.96 μg/kg. Heating rate had a significant effect on the PAH content of rapeseed oil (P<0.05), with benzo[a]pyrene, PAH4, and EPA16 contents of 0.91, 7.18, and 40.92 μg/kg observed, respectively, under rapid heating and 0.38, 3.21, and 27.99 μg/kg observed, respectively, under slow heating. However, heating rate had no significant effect on either the polyphenols, tocopherol, and sterol contents or the types and content of volatile compounds in the oil (P>0.05). The acidity of the rapeseed oil decreased by 0.45 mg/g and the peroxide value increased by 0.49 mmol/kg after degumming. The L* and b* of the rapeseed oil increased significantly, while the a* value decreased. Lipid oxidation and Maillard reaction products in the rapeseed oil decreased by 31.19 % and 53.05 %, respectively. The results could provide valuable reference for the optimization of parameters in the production of strongly flavored rapeseed oil.