Microencapsulated Hovenia dulcis: application in yogurt and evaluation of gastrointestinal digestion in vitro

This study aimed to determine if adding different forms of Hovenia dulcis (HD) to yogurt enhances bioactive compound concentrations and their effects on gastrointestinal digestion (in vitro). Freeze-dried (Y-HD) and microencapsulated (YEn-HD) forms were added to various yogurt formulations. The yogurts were analyzed on days 1 and 21 post-processing revealing no changes in the fermentation kinetics, proximate composition, water-holding capacity, and hardness of the different formulations. Lower Hunter Whiteness (p>0.05) was observed in yogurts with free and encapsulated (Y-HD) compared to the control (without HD). Although YEn-HD yogurt provided higher values of total phenolic compounds, there was no difference before and after the digestion process. An opposite result was observed for ABTS, which able to be determined only after passing through gastrointestinal digestion, with an 83% higher value in YEn-HD compared to Y-HD. This increase may be due to the conditions of the digestive environment, which can cause changes in molecular structure and form new compounds with bioactive effects. This study shows that HD microcapsules can be prepared using the freeze-drying method, becoming a natural and promising additive to increase bioactivity in dairy products such as yogurt, particularly after the digestion process.