I. Experimental Design
The deep frying process was continued for 48 h for two
kinds of oils (soybean oil and palm olein) and three of the
most common frying foods in Taiwan (French fries, chicken
leg fillet and pork chop). Used oil samples were taken every
6 h for quality analysis. The rapid measurements on the
content of total polar compounds and acid value of used
oil were performed on site, and the same parameters were
assessed again using standard methods later for comparison.
The effects of oil types and foods on the content of total polar
compounds and acid value in used oils were determined by
statistical analysis.