Effect of wall materials on some physicochemical properties and release characteristics of encapsulated black rice anthocyanin microcapsules.

Anthocyanin-rich extracts derived from the bran of a select Thai black rice cultivar, Leum Pua, were encapsulated by spray drying. In this microencapsulation method, twelve wall materials comprising maltodextrin (M), gum arabic (G), whey protein isolate (W), and their combinations were employed. For comparison, an ionic gelation method was employed using alginate-whey protein isolate (AL-W) as a wall material. Thirteen microcapsules were analysed by scanning electron microscopy, and their encapsulation efficiencies were almost 100%, except for that of the W (83%). M (88%) and its combination with W exhibited the best anthocyanin retention, while pure W contained the highest amount of total phenolic compounds and antioxidant activity. An in vitro digestion study using simulated gastrointestinal fluids revealed the highest released total phenolic content and antioxidant activity of the intestinal fluids when the microcapsule was spray-dried with pure W.

Cold plasma treatment to improve germination and enhance the bioactive phytochemical content of germinated brown rice.

The changes in the bioactive phytochemicals of six cultivars of Thai germinated brown rice (GBR) were monitored in parallel to those of cold plasma-treated GBR (PGBR). After treatment with the optimal plasma conditions, the germination percentage, root length, and seedling height measurements of the most sensitive rice cultivar increased by 84%, 57%, and 69%, respectively. For all of the rice cultivars, there were no significant differences in the antioxidant activities of the GBRs and PGBRs. Conversely, higher contents of γ-oryzanols were observed in the PGBR group than in the GBR group during the 2-day germination period. Certain cultivars in the PGBR group reached their maximum values for total phenolic compounds, total vitamin E, certain simple phenolics, phytosterols, triterpenoids, and anthocyanins one day earlier than the same values for GBR. In contrast, the concentrations of 2-acetyl-1-pyrroline in both the GBR and PGBR samples were reduced significantly with increased germination time.