Automated Olive Oil Malondialdehyde Determination  by Flow Injection

• Measurement of malondialdehyde is based on the reaction with 2-thiobarbituric acid (TBA). This reaction is not specific so the term usually  used is 2-thiobarbituric acid reacting substances (TBARS).
  
• Olive oil samples are injected in a 2.0 x 10^-2 M TBA stream and acidified by merging with a 0.10 M CCl₃COOH in n-propanol stream. The resulting reaction mixture is diverted to an incubation coil. All ten incubation coils that are immersed in a water-bath at 95 ^oC are loaded in 5 min. Then, the flow is stopped for 25 minutes. After sample incubation, the reaction mixture is cooled by passing through an ice-bath and the reaction products are measured in the spectrophotometer.
  
• The developed method achieves an analysis rate of 20 samples per hour, while samples are incubated for 30 min. The proposed method compares well with a manual method (relative difference 0-6.2% for the analysis of 30 olive oil samples). Click to see the advantages of the method.
  

Questions and comments to author: Dr C.A. Georgiou, cag@aua.gr
Phone: +3010-5294248, fax: +3010-5294265
Chemistry Laboratory, Agricultural University of Athens, Greece