Influence of Lipid Content in a Corn Oil Preparation on the Bioaccessibility of β-Carotene: A Comparison of Low-Fat and High-Fat Samples.

Some individuals with fat maldigestion have compromised digestive systems, which causes the incomplete hydrolyzation of ingested lipids within the gastrointestinal tract (GIT). We studied the influence of high-fat (20%) and low-fat (4%) contents on the bioaccessibility of a highly hydrophobic nutraceutical (β-carotene) through a simulated GIT model consisting of mouth, stomach, and small intestine phases. The low-fat and high-fat values were chosen to simulate low-fat and high-fat diets. The triglycerides in the low-fat system were fully digested, whereas those in the high-fat system were only partially digested, thereby mimicking the digestive systems of individuals who exhibit fat maldigestion. The carotenoids were initially solubilized within oil-in-water nanoemulsions prepared using a nonionic surfactant (Tween 20) as emulsifier and a long-chain triglyceride (corn oil) as the oil phase. After digestion, the total β-carotene concentration in the filtered micelle phase was much greater for the high-fat group (0.072 μg/mL) than for the low-fat group (0.032 μg/mL). Conversely, the β-carotene bioaccessibility of the high-fat group (39%) was much lower than that of the low-fat group (84%), which was attributed to a fraction of the carotenoids remaining in the nondigested lipid phase of the high-fat group. These results highlight the importance of delivering hydrophobic nutraceuticals in a form where the fat phase is fully digested.