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 1 of palm olein using a zero turnover of fresh fat until a polar content of 25% was reached. A total of 90 fryings were required. Total alteration significantly 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, respectively. Triglyceride polymers, triglyceride dimers and oxidized triglycerides 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 administered to rats at the level of 1 g/100 g body weight, a significant decrease was noted after 4 h experiment in the true digestibility and true absorption coefficients (p<0.05). However, the content of intracellular gastrointestinal fat did not change. The changes in digestibility and absorption were negative and highly correlated with total alteration and with thermoxidative alteration compounds (p<0.01). Results suggest that palm olein with a high level of thermoxidative products was digested less efficiently than the fresh one but did not affect the clearance of intracellular gastrointestinal fat.