Microencapsulation of green tea extract (Camellia sinensis var assamica) to increase the bioaccessibility of bioactive compounds and gastroprotective effects

Abstract

Green tea has polyphenols and flavonols as its main bioactive constituents, nonetheless, these compounds present sensitivity to external factors. Microencapsulation is a technique that can be used to protect the main bioactive constituents of green tea. This research was carried out aiming to obtain scientific evidence on the in vitro simulated gastrointestinal digestion (SGD) of the green tea extract (Camellia sinensis var assamica) microencapsulated with cashew gum and maltodextrin and the gastroprotective action of these microcapsules in an experimental model of gastric lesion induced by ethanol in mice. The microencapsulation (GTM) process was able to increase the bioaccessible percentage of polyphenols and antioxidant activity of green tea after SGD in vitro, resulting in values equal to 28.2 and 24.2%, respectively. On the other hand, the bioaccessible percentage obseverd for green tea extract (GTE) was equal to 25.9 and 14% for the phenolic compounds and antioxidant activity, respectively. It was verified an action dose-way dependent related to the administration of GTE and GTM and their gastroprotective effects. The concentration of 10 mg/kg presented effective protection of the gastric mucosa, providing the maintenance of glutathione in the tissues after the alcoholic induced lesion and in the same concentration, the samples were able to avoid the lipidic peroxidation due to the reduction of malonaldehyde levels in the tissues. In general, GTM presented a great potential to contribute to the obtention of new products enriched with green tea, presenting also gastroprotective effect being beneficial to the consumer's health.