The Studies On Benzo(a)Pyrene Content In Plantsoil And Edible Oils And Fats

Due to its strong carcinogenic potential, benzo[a]pyrene (BaP) has been definedas Group1(known carcinogens in humans) by the International Agency for Researchon Cancer, GB2716-2005adopted a legal limit of10ppb for BaP content in oils andfats. However, edible oils and fats can be heavily contaminated with these xenobioticsubstances and probably exceed the legal limit due to the wide distribution of PAHs inthe environment and their lipophilic nature, or improper processing conditions.Research on the BaP content influence of processing conditions system has not beenreported. The purpose of this study was to research the impact of environmentalpollution, roasted conditions, the process conditions of decolorization, and the processconditions of alkali refining for the BaP content in the oils, and provide a techniquesupport for oil safe production.(1) A method for detection of BaP content in edible oil using liquidchromatography-tandem mass spectrometry (LC-MS/MS) was developed andvalidated. The pre-processing was simple, and the analysis time is short. The proposedmethod was used to study the BaP content of peanut, sesame, and rapeseed fromdifferent regines, and the results showed that the BaP content ranged from0-14.96μg/kg. Only the BaP content of two samples was exceed10μg/kg, and the ratio wasless than10%.(2) Considering sesame oil flavor, color and oxidation stability, the best rostaingtemperature for sesame was200℃, roasting time is not more than20minutes; thebest rostaing temperature for peanut was200℃, roasting time is not more than20minutes; and the best drying temperature for reapseed was not than180℃, time isnot more than20minutes; on that condition, there was no influence on the BaPcontent in the oils.(3) For rapeseed oil, considering the production cycle time and cost, the optimumprocess conditions were as follows: the ratio of mixed adsorbent was0.03%+4%(activated carbon+activated clay), bleaching time was20min, bleaching temperaturewas100℃, the BaP removal rate of rapeseed oil reached96%, the residual amount of BaP was0.40μg/kg.(4) Alkali refining has a certain role for the removal of BaP in grease, but theeffect is limited. The optimum conditions for sesame oil production were: alkalirefining time was50min, the alkali concentration was10°Bé, ultra-alkali contentwas0.2%, the alkali refining temperature was70℃, and the residual BaP contentwas5.74μg/kg. The BaP removal efficiency for the sesame oil, which BaP contentwas18.23μg/kg, the R value was10, Y value was20, reached70%, the R value was2.0, and the Y-value was14. The optimum conditions for rapeseed oil production were:alkali refining time was30min, the alkali concentration was8°Bé, the content ofultra-alkali was0.4%, alkali refining temperature was60℃. The BaP removalefficiency for the rapeseed oil, which BaP content was10.1μg/kg, the R value was5,Y value was40, reached45%, was5.56μg/kg, the R value was2.2, and the Y-valuewas30; Therefore, it can be used as an auxiliary means of BaP removal.