Fresh Brassicaceae sprouting broccoli (Bimi®) glucosinolates profile characterization and bioaccessibility through an in vitro dynamic digestion study

Abstract

Bimi® (Brassica oleracea Italica x Alboglabra) glucosinolate content was determined as 83.64 mg/100 g of fresh sample, mainly characterised by aliphatic (61 %) and indolic (39 %) glucosinolates. Glucoraphanin was the main compound (36.75 ± 1.96 mg/100 g) followed by glucosbrassicin (22.46 ± 6.37 mg/100 g) and progoitrin (11.95 ± 1.31 mg/100 g). Other remarkable compounds were neoglucobrassicin, 4-methoxyglucobrassicin and gluconapin. An in vitro Dynamic Gastrointestinal Digester system (DGD) was used to simulate the gastrointestinal digestion. Important reductions of glucosinolates were observed (bioaccessibility of 23 %), where aliphatic compounds were the most bioaccesibles. The main glucosinolate in the bioaccesible fraction was the glucoraphanin (13.20 ± 3.66 mg/100 g of fresh sample). Other bioaccesible compounds detected in a lesser extent were progoitrin, glucobrassicin, 4-methoxy-glucobrassicin, gluconapin, glucoalisin and neoglucobrassicin. Therefore, diverse intact glucosinolates (together with well-known derived isothiocyanate generated during digestion process) are available after the digestion process. Compared to the literature data of its constitutive plant (broccoli), Bimi® showed a similar trend in glucosinolate profile but, in general, higher amounts. Close bioaccessibility values were also determined compared broccoli. This study suggests that a chronic intake of Bimi® may allow a chronic intake of bioaccesible glucosinolates such as glucoraphanin, generaly recognized as an anticancer compound.