Microcapsules obtained by spray-drying from an ultrasonic aqueous extract of Verbena officinalis L.: Bioactivity analysis, shelf-life prediction, and in vitro gastrointestinal digestion

• Production of bioactive microcapsules using only water in edible materials • High process yields and microencapsulation efficiencies of verbena bioactivity • Bioactive microcapsules without stickiness problems during storage from 20 to 60 °C • Accurate prediction of the shelf-life of microcapsules by mathematical models • Bioactive microcapsules with high bioavailability after gastrointestinal digestion Verbena officinalis L. is a source of bioactive compounds that can be used in food products. However, consumers often reject it due to its bitter taste, which is caused by terpenoids. This study aimed to preserve bioactivity and mask the bitter taste using spray-drying microencapsulation, with the purpose of increasing the bioactivity of food by adding these microcapsules. This study is pioneering in its application of mathematical models to predict the shelf life of bioactive microcapsules. Optimal microencapsulation conditions were found to be 140°C with 5% maltodextrin (DE-10). Microencapsulation yielded 63.0%, with microencapsulation efficiencies of 71.9% for phenolic compounds and 72.0% for flavonoids, which exhibited good thermal stability (Tg = 78°C) and rough spherical morphology with a size of 7.69 ± 2.19 µm. In vitro gastrointestinal digestion bioactivity protection was 72.4%, 84.0%, 60.3%, and 77.9% for phenolic compounds, flavonoids, DPPH, and ABTS antioxidant capacity, respectively. The Weibull and Gammariello models accurately estimated the shelf life of microcapsules stored without packaging, whose values were from 18 to 32 days, depending on the assessed bioactivity, with R² values ranging from 0.988 to 0.996, and overall average relative error from 2 to 5%. These mathematical models can be used to estimate the shelf life of bioactive microcapsules and determine their storage stability. This information is useful for incorporating them into food products and encourages their commercialization.