Bioaccessibility of glucoraphanin from broccoli using an in vitro gastrointestinal digestion model

Abstract

This study investigated the effect of cooking methods on the degradation of glucoraphanin (GR) in broccoli and the bioaccessibility of this compound through simulated gastrointestinal digestion. Broccoli was cooked using three different techniques: boiling, steaming and microwave cooking. Then, GR was extracted and quantified by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). In addition, the cooked samples were added to a system that simulates the digestion characteristics of the mouth, stomach and duodenum. Samples were drawn before and after the digestion, and GR bioaccessibility was calculated. GR losses were higher when broccoli was boiled (47.03%), followed by steaming (31.96%) and microwaving (11.87%). However, steamed broccoli presented the highest bioaccessibility (94.59%), followed by boiled (89.69%) and microwaved (60.88%). Taking into consideration the levels of remaining GR after cooking and its bioaccessibility after simulated digestion, steaming can be considered the best method and may result in the highest levels of this bioactive glucosinolate after broccoli intake.