Phenolic Compounds of Olive Oil: Intake and Behavior in In Vitro Static Simulated Digestion Without or with Cellulose

The effects of phenolic compounds in the gastrointestinal tract are linked to their intake in the diet and their interactions with the food matrix. The aim was to estimate the intake of phenolic compounds from two olive oils and to assess their behavior in the gastrointestinal tract after simulated static in vitro digestion without or with added cellulose, as a preliminary result on the influence of cellulose on their behavior. Individual phenolic compounds were quantified by RP-HPLC. The two olive oils were characterized by phenyl alcohols (1.8% and 5.3%), flavones (1.1% and 2.4%), lignans (0.8% and 1.7%), and unidentified secoiridoid derivatives (96.3% and 90.7%). The estimated population daily intake of phenolic compounds based on EFSA consumption data for the analyzed olive oil samples had means 0.75 to 1.27 and 0.30 to 0.51 mg per day, with the 95 percentile up to 5.91 and 2.38 mg per day for olive oil 1 and 2, respectively. The total amounts after gastric and intestinal digestion significantly decreased. Phenolic subgroups showed different behavior. In the stomach, phenyl alcohols increased, while all other subgroups decreased. After the intestinal phase, some subgroups additionally increased (phenyl alcohols, flavones, lignans), while others decreased (secoiridoids). Cellulose increased recovery in the stomach. As a preliminary result, the influence of cellulose needs to be studied further.