Medium- and long-chain triacylglycerol has higher digestibility and bioaccessibility compared with physical mixed oils under conditions of bile salts secretion deficiency

Bile salts play a major role in intestinal lipid digestion. In this study, the effects of bile salts concentration on the digestive characteristics and bioaccessibility of two oils with the same fatty acid composition but different triacylglycerol structures, physical mixed oil (MO) and medium- and long- chain triacylglycerol (MLCT), were investigated under simulated gastrointestinal conditions. Results revealed that as the bile salt concentration increased from 0.0 mg/mL to 5.0 mg/mL, the free fatty acids (FFAs) release of both oils exhibited an increasing trend. MLCT presented higher free fatty acids release and more stable release rate. Furthermore, at a bile salt concentration of 5.0 mg/mL, the bioaccessibility of FAs in MLCT was significantly higher than that in MO, with respective values of 79.51 ± 1.19 % and 74.69 ± 1.02 % (p < 0.05). Notably, even in conditions of bile salts deficiency, especially at a bile salt concentration of 1.0 mg/mL, the bioaccessibility of FAs in MLCT remained superior to that in MO, reaching levels of 43.29 ± 0.89 % and 46.47 ± 1.31 %, respectively, with statistical significance (p < 0.05). Theses findings further demonstrated that MLCT exhibits superior digestion characteristics. This study provided a scientific basis for the selection of nutritional lipids in clinical nutrition support.