Assessment of the bioaccessibility and bioavailability prediction of omega 3 and conjugated fatty acids by in vitro standardized digestion model (INFOGEST) and cell model

Omega 3 EPA and DHA are polyunsaturated fatty acids with relevant health benefits. Conjugated linoleic and linolenic acids are known for their anti-carcinogenic effect, anti-inflammatory properties and body weight reduction. To achieve therapeutical doses, high amounts of these fatty acids’ food sources must be consumed. Thus, the intake of enriched oils with a high concentration of these fatty acids is often used. But several factors influence their bioavailability. Here, by using the INFOGEST static in vitro protocol of gastrointestinal tract digestion it was studied the bioaccessibility of these fatty acids in different matrixes: Pomegranate and Fish oil and omega 3, CLA and CLNA soft-gel enriched capsules. After digestion, the Recovery Index for the major bioactive PUFAs are very low: Pomegranate oil is 2%, Fish oil 11–13%, CLNA 17%, CLA 6% and Omega 3 capsules 3%. Higher initial concentrations of these PUFAs seem to be related to higher degrees of oxidation. In Pomegranate oil, CLNA and Omega 3 capsules, the digestion process negatively influenced the antioxidant potential. The opposite was verified for the Fish oil and CLA capsules. Importantly, bioaccessibility studies of similar matrixes are very scarce and intestinal permeability is absent in most of the studies. Intestinal permeability studies were performed using a Caco-2/HT29-MTX co-culture: there is significative incorporation of the bioactive fatty acids into the intestinal cells, which may affect their permeability performance. Interestingly, most fatty acids remain in the non-bioaccessible fraction which may be relevant when designing oral routes of administration and in gut microbiota modulation.