Valorization of anthocyanin-rich coproducts, such as broken Homnil rice (HN), is limited by the poor kinetic stability of anthocyanins during storage, constraining their use in value-added functional foods. This study aimed (i) to mechanistically link the structural and thermodynamic properties of maltodextrin/pectin-encapsulated HN powders to anthocyanin stability and (ii) to compare two low-temperature drying treatments, freeze-drying (HNFD) and vacuum-drying at 60 °C (HNVD), as stabilization strategies. HNFD developed a highly porous matrix and significantly higher encapsulation efficiency (88.93%, p 0.99, identifying the monolayer moisture content (M0) as the critical thermodynamic stability threshold and confirming that the initial water activity of HNFD (aw = 0.1743) lies within this stable M0 region. These findings demonstrate that freeze-drying confers a superior kinetic and thermodynamic barrier to anthocyanin degradation compared to vacuum-drying and, for the first time for this system, provide integrated Tg-Ea-GAB (M0) metrics that move beyond empirical shelf life descriptions to support predictive process and packaging design (e.g., choosing drying conditions, storage humidity, and barrier properties) for long-term stability of functional food powders derived from rice coproducts, enabling more robust shelf life predictions for rice coproduct powders.
Boonsan et al. (Mon,) studied this question.