Suspect screening boosts bioaccessibility assays of phenolic compounds in food commodities: A proof of concept

Abstract

The knowledge of the actual oral bioaccessibility of phenolic compounds through food intake in the human gut isa key factor for assessing their potential health benefits. To this end, there is a quest to develop advancedanalytical methodologies that are able to expand the chemical space offered by targeted methods. In fact, suspectscreening workflows using high-resolution mass spectrometry might shed light on the vast diversity of phenoliccompounds in food commodities that might be released in the gut fluids. Herein, targeted and suspect screeningassays of phenolic substances in gastric extracts were performed to investigate the relative bioaccessibility ofthese compounds in the crushed solid fruit as compared to the fruit juice intake. The analytical method wasvalidated for 30 phenolic compounds using a targeted workflow in both positive and negative modes, withdynamic linear ranges spanning from 1.0 to 4000 ng/mL and repeatability values ranging from 0.3 to 13.6%under matrix-matched calibration. Validation was performed in a pH-adjusted gastric extract, with the negativemode offering the most sensitive detection for subsequent real sample analysis. Thereafter, suspect screeningworkflows of the phenolic compounds and their plant metabolites were conducted in juiced and crushed fruitsafter the gastric extraction process. The workflow resulted in the confirmation of 8 features with pure standards(level 1), and 24 additional tentative annotations in levels 2–4. The results demonstrated that 59.4% of phenoliccompounds annotated in the gastric extracts have higher relative acid bioaccessibility from the solid fruit, 34.4%higher from the juiced samples, and 6.2% equally distributed. Additionally, the targeted and suspect resultsindicated that there was a significant correlation between the number of phenolic hydroxyls on the relativebioaccessibility of the compounds. However, the relevance of the type of phenolic compounds, e.g., beingflavonoid or non-flavonoid, was not statistically significant. This study aims to provide a holistic perspective onhow the form of food intake (juice versus whole fruit) can be strategically selected according to specific phenoliccompounds to achieve bespoke nutritional and food industry benefits.