Abstract
A chemical and biological evaluation of two frying palm oil samples (A and B) discarded by commercial restaurants is reported. The degree of deterioration of the discarded palm oil was chemically estimated by 10 ordinary laboratory methods and five quick-test methods, and the biological effects of the oil were investigated by feeding rats with standard diet containing 20% discarded palm oil for 28 days. The chemical measurements indicated a severe deterioration during frying operations, particularly in sample A, which increased liver index and induced a nonsignificant decrease in platelet aggregation when compared with sample B. Both samples reduced spleen index, but had no effects on animal growth, heart and thymus indices, or aorta prostacyclin release.