3.5 Determination of 3-MCPD esters in oil samples
Soybean oil, rapeseed oil, palm oil and peanut oil were detected by gas
GC-MS, which was established by enzyme-hydrolyzed sample pretreatment
method. According to the experimental method of 2.5, each sample was
measured six times in parallel to take the average value, the content of
3-MCPD ester was calculated according to the peak area and linear
regression equation obtained by GC-MC detection. The contents of 3-MCPD
ester in palm oil, peanut oil, rapeseed and soybean oil were as follows:
5.52, 3.02, 2.87 and 2.73 mg/kg.
Conclusion
In this study, the optimal
conditions for enzymatic hydrolysis of 3-MCPD esters were obtained by
single factor test as follows: lipase from Candida sp. was selected,
enzyme concentration was 150 U/mL, the enzymatic hydrolysis temperature
was 25℃, the enzymatic hydrolysis time was 30 min, and the pH was 5.
Secondly, the standard curve of the 3-MCPD standard solution was drawn,
and then the edible oil sample was processed before enzymatic hydrolysis
according to the optimal enzymatic hydrolysis conditions, derived with
PBA, and finally detected by GC-MC. The content of 3-MCPD ester in four
kinds of vegetable oil was obtained by combining the standard curve, and
the content of 3-MCPD ester in food oil could be detected simply and
quickly.