Probe-ultrasound extraction and spray-drying microencapsulation of bioactive compounds from araticum (Annona crassiflora) juice

Abstract

The Brazilian Cerrado hosts native fruits with high nutritional and functional potential, yet they remain underexplored in terms of technological innovation. Among them, araticum (Annona crassiflora) stands out for its content of phenolic compounds, carotenoids, and vitamin C; however, its utilization is constrained by high perishability and by the susceptibility of its bioactives to processing and storage conditions. Accordingly, this thesis aimed to develop and assess an integrated strategy to valorize araticum by combining probe-ultrasound intensification to enhance the release of target compounds with juice stabilization through spray-drying microencapsulation, ultimately producing a more stable powder ingredient suitable for food formulations. The thesis is structured into four articles: first, a critical review with bibliometric analysis of drying technologies applied to fruits of the Annona genus and their effects on quality and bioactive preservation; second, an experimental study on ultrasound-assisted extraction, evaluating different intensities and treatment times and their effects on bioactive compounds and technological attributes of the juice; third, optimization of spray-drying microencapsulation using a Taguchi experimental design, investigating inlet temperature and wall systems based on maltodextrin and whey protein concentrate (WPC), including the assessment of retention and in vitro bioaccessibility; and fourth, a comparison of wall matrices (WPC, maltodextrin, and WPC–maltodextrin mixtures) in terms of drying performance and the physicochemical, structural, thermal, and morphological properties of the resulting powders. Overall, lower power settings and extreme treatment times provided the best balance between compound-release efficiency and preservation, and the juice exhibited nonNewtonian pseudoplastic behavior with good fit to rheological models. Regarding drying, the evidence indicated that mixed protein–polysaccharide matrices, particularly at an intermediate inlet temperature of 125 °C, promoted higher powder recovery, lower water activity, and more homogeneous particles, as well as more consistent functional performance. Collectively, these findings provide a technical–scientific basis for converting araticum into a powdered ingredient and for advancing sustainable routes to valorize native Cerrado fruits.ices tailored to local conditions.