Quality assessment of heated cooking oil, agab, using a simple newly-developed spectrophotometric method.

摘要

Deep fat frying is one of the most widely used cooking practices but heat treatment produces many degradation products, some of which may cause health hazards. A simple, rapid, and inexpensive method for assessment of the quality of cooking oil used for frying was developed using a spectrophotometer. Potato slices were heated in Agab oil (soybean/sunflower:1/l volume) at 180 +or- 5 degrees C for 8 h per day for 6 consecutive days. Heated samples were collected at 15-min intervals and UV absorbance at lambda = 370-400 nm was measured; samples were also analyzed for anisidine value (AV), conjugated diene formation (CD), and total polar compounds (TPC). A systematic increase of absorbance in heated oil over frying time was observed. TPC was highest (R2 = 0.99) for the correlation with heating time followed by CD (0.93) and AV (0.89). The spectrophotometric method developed in the present study to assess the quality of heated oils is simple, quick, and reliable because its results were strongly correlated with the results from the TPC