Polysaccharides-protein-based microencapsulation of anthocyanin-rich riceberry rice extract and its incorporation into rice gel matrices via 3D food printing.

This study aimed to investigate the effects of selected extraction conditions, microencapsulation systems, and 3D food printing on the stability and bioavailability of bioactive compounds from riceberry rice. The effects of extraction temperature, solvent type, and solid-to-solvent ratio on total phenolic content (TPC), total anthocyanin content (TAC), and antioxidant activity were evaluated. Among the tested conditions, extraction at 80 °C using 50% (v/v) ethanol and a 1:10 solid-to-solvent ratio resulted in higher TPC (3.78 mg GAE/g extract) and TAC (480.92 μg C3G/g extract) compared to the other conditions evaluated, together with strong antioxidant capacity. The extract obtained under these conditions was microencapsulated using gelatin-inulin (GI), gelatin-gum arabic (GG), and gelatin-carrageenan (GC) systems. Encapsulation efficiency ranged from 52.72% to 78.38%, with GG exhibiting superior uniformity and balanced release, while GC showed high thermal antioxidant retention. Microcapsules were incorporated into 3D-printed rice gels formulated from CNT1, RD43, and KDML105 flours processed by conventional or ultrasound-assisted heating. Ultrasound treatment improved gel porosity and created a more uniform internal structure, especially in low-amylose rice gel matrices containing anthocyanin-loaded microcapsules. This structural improvement enhanced the release of anthocyanins and phenolic compounds during in vitro digestion. The results suggest that combining ultrasound-assisted extraction, appropriate microencapsulation systems, and 3D printing was associated with enhancements in functional stability and gastrointestinal bioaccessibility of anthocyanin-rich riceberry rice extracts, offering a promising approach for developing antioxidant-enriched functional foods.