Influência das forças mecânicas na digestão in vitro de sistemas de entrega baseados em proteína de soja

Abstract

Resveratrol is a bioactive compound that can provide health benefits. However, to allow its controlled release in the gastrointestinal tract (GIT) and improve its bioaccessibility and bioavailability it has to be incorporated in carrier systems. In vitro digestibility assays are often employed for assessing the gastrointestinal fate of delivery systems, due to their lack of ethical restrictions, greater experimental ease, low cost, in addition to good reproducibility.Static in vitro models are the most applied, as they are able to simulate biochemical parameters of digestion. Dynamic in vitro assays can reproduce digestion dynamics, and thus, should provide realistic information on the digestion process. In this work, a gastric dynamic prototype, based on the TIM-1 model, was developed and validated for further use in digestibility assays. Moreover, carriers systems incorporating trans-resveratrol (liquid and gelled emulsions) stabilized by soy protein isolate were produced by distinct processes (protein denaturation before or after homogenization step) and evaluated by in vitro static or semi-static (in which the gastric step of digestion was simulated on the developed model) digestion assays. Liquid emulsions underwent coalescence and flocculation at the gastric step in both approaches. Gelled emulsions, otherwise, were more resistant to the gastric environment, and the gel network was degraded only at the small intestine step. Thus, they promoted higher protection to the incorporated resveratrol. Moreover, emulgels had a smaller oil droplet size at the semi-static assay, thereby the mechanical forces affected their digestive behavior. The bioaccessible fraction of trans-resveratrol (BF(%)) was over 68% for all the delivery systems. Besides that, BF (%) of liquid emulsions was higher in the static models.Thereby, semi-static approaches that reproduces more accuratedly the gastrointestinal must be preffered, as static approaches can lead to overestimated results. Soy protein-based delivery systems were effective carriers of resveratrol. Also, carrier structuring and the digestibility model had an effect on the digestive behavior and release properties of the carriers under simulated GIT conditions.