DIGESTIBILITY AND ABSORPTION-COEFFICIENTS OF PALM OLEIN - RELATIONSHIPS WITH THERMAL-OXIDATION INDUCED BY POTATO FRYING

Sets of 500 g of potatoes were discontinuously fried in 3 l of palm ol ein using a zero turnover of fresh fat until a polar content of 25% wa s reached. A total of 90 fryings were required. Total alteration signi ficantly increased (p<<0.001) with the number of fryings from 9.27 mg/ 100 mg oil to 14.81 and 26.36 mg/100 mg oil after 40 and 90 fryings, r espectively. Triglyceride polymers, triglyceride dimers and oxidized t riglycerides significantly increased (p<<0.001) from 0.12, 1.02 and 1. 12 mg/100 mg oil in the fresh oil to 3.67, 7.92 and 8.32 mg/100 mg oil after 90 fryings, respectively. When these palm oleins were administe red to rats at the level of 1 g/100 g body weight, a significant decre ase was noted after 4 h experiment in the true digestibility and true absorption coefficients (p<0.05). However, the content of intracellula r gastrointestinal fat did not change. The changes in digestibility an d absorption were negative and highly correlated with total alteration and with thermoxidative alteration compounds (p<0.01). Results sugges t that palm olein with a high level of thermoxidative products was dig ested less efficiently than the Fresh one but did not affect the clear ance of intracellular gastrointestinal fat.