压榨亚麻籽油中苯并(a)芘含量超标的防控措施研究

Prevention and control measures of benzo(a) pyrene in pressed flaxseed oil

针对亚麻籽油产品质检经常出现苯并(a)芘含量超标问题,通过模拟实验研究了炒籽压榨生产亚麻籽油工艺中炒籽温度、炒籽时间对压榨亚麻籽油中苯并(a)芘含量的影响规律和防控措施。结果表明:炒籽温度超过180℃后,炒籽温度越高,压榨亚麻籽油中苯并(a)芘含量越高,且苯并(a)芘含量超过国标限量值(10μg/kg)的炒籽时间越短,说明炒籽温度过高是出现产品苯并(a)芘含量超标的主要原因;热重分析实验发现亚麻籽在172~174℃有热失重速率谷值,超过该温度后,热失重速率快速升高,说明有机物大量裂解从而快速生成苯并(a)芘;结合炒籽实验和热重分析实验,防控苯并(a)芘含量超标的适宜炒籽温度为不高于170℃;170℃炒籽75 min压榨得到的亚麻籽油苯并(a)芘含量低于食品安全国家标准限值(10μg/kg),可以作为有效防控苯并(a)芘含量超标的技术措施。

In view of benzo(a)pyrene content in flaxseed oil to be in excess of the national standard,the effects of roasting temperature and roasting time on the content of benzo(a)pyrene in pressed oil and the technical measures to prevent the excess of benzo(a)pyrene were studied by simulation experiments.The results showed that when the roasting temperature exceeded 180℃,the higher the roasting temperature,the higher the content of benzo(a)pyrene in pressed flaxseed oil,and the shorter time when the content of benzo(a)pyrene exceeded the limited index(10μg/kg),which indicated that the high roasting temperature was the main reason for benzo(a)pyrene exceeding the national standard.The thermogravimetric analysis showed that flaxseed had the valley value of thermogravimetric loss rate at 172-174℃,and when the temperature exceeded it,the rate of thermogravimetric loss increased rapidly,which indicated that the organic matter was cracked in large quantities and benzo(a)pyrene formed rapidly.Combined with roasting experiment and thermogravimetric analysis,the optimal roasting temperature of preventing and controlling benzo(a)pyrene over national standard was no more than 170℃.The content of benzo(a)pyrene in pressed flaxseed oil produced from flaxseed roasted at 170℃for 75 min was lower than that of food safety standard(10μg/kg),and it could be used as an effective measure to prevent and control benzo(a)pyrene exceeding the limitation.