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The formation of fungal colonies, mycotoxins, phenolic compounds, cooking quality and color properties were evaluated in freshly-harvested brown, black, and red rice grains and then subjected to ultraviolet radiation (UV-C) for 1 and 3 h. Assessments were made after 6 months of storage. The exposure of black and red rice at 1 h of UV-C was enough to decrease the presence of fungal colonies by 22% and 79%, respectively, without any changes in cooking and coloring properties. In brown rice, only 3 h of UV-C irradiation was able to reduce the formation of fungal colonies. The release of phenolic compounds associated with cell wall was observed only in black and red rice subjected to UV-C radiation. The levels of mycotoxins gradually decreased with the increase in the time of exposure to UV-C radiation, demonstrating UV-C irradiation to be an effective method in fungal control and reduction of mycotoxins in stored rice., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This study aimed to evaluate the influence of transglutaminase addition on the technological properties and in vitro starch digestibility of gluten-free cakes of brown, black, and red rice, as well as the effect of baking on the content of phenolic compounds. Transglutaminase addition exerted significant effect in the technological properties only in the brown rice cake, resulting in a decrease in crumb firmness and an increase in the specific volume. Red rice cakes treated with transglutaminase presented a lower glucose release rate (k) compared to cakes without the enzyme. Cakes from pigmented rice varieties had lower crumb firmness and k values than brown rice cakes. Baking reduced only the contents of ferulic and p-coumaric acids and significantly increased the extractability of hydroxybenzoic, caffeic, caftaric, and protocatechuic acids. However, the addition of the enzyme resulted in a slight decrease in the total phenolic content of the cakes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This study aimed to investigate the influence of drying temperatures (20, 40, 60, 80, and 100 °C) followed by 12 months-storage under normal-atmosphere (conventional), nitrogen-atmosphere, and vacuum-atmosphere on black rice phenolics. Increase in drying temperature reduced the total content of free-phenolics, free-flavonoids, and anthocyanins. An increase in bound phenolics extractability was observed at 60 and 80 °C, suggesting some extent of phenolics polymerization and complexation at these drying temperatures. The free fraction of ferulic, caffeic, p-coumaric, and gallic acids were the most thermally unstable compounds. After storage, no reductions were observed only for free caffeic and protocatechuic acids. For total flavonoids, an increase in the free fraction and reduction of the bound fraction were observed in the grains stored under conventional- and vacuum-atmosphere. A reduction of total phenolics occurred regardless of the storage condition. However, storage under nitrogen-atmosphere is the most recommendable condition for maintenance of phenolics in black rice., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

To evaluate the digestibility of rice allergenic and nonallergenic proteins under the influence of the rice grain matrix, rice powder was subjected to in vitro digestion by simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Rice proteins were extracted from the liquid and the solid phases and analysed by SDS-PAGE, and rice allergenic proteins were detected by a multiplex immunodetection method. The digestion of soluble proteins was carried out in both liquid and solid phases, while that of insoluble proteins only occurred in the solid phase. In SGF digestion, rice proteins were more quickly digested at pH 1.2 than at pH 2.0 or 2.5. Moreover, the digestibility of five kinds of rice allergenic proteins was influenced by pH level, heat processing, starch matrix, solubility, and protein properties, on a case-by-case basis. On the other hand, all detected rice allergenic proteins and non-allergenic proteins were rapidly digested in SIF., (Copyright © 2014 Elsevier Ltd. All rights reserved.)