Comparing parboiling and milling for selenium-enriched rice (Oryza sativa L.): Differences in selenium speciation, texture, microstructure, and sensory

Parboiled rice can effectively retain Se during milling. In this study, Se-enriched rice grains were sprayed with three different concentrations of bioSeNPs fertilizer on the leaves at heading stage and then processed into parboiled and milled rice. The aim was to investigate the effects of parboiling on Se speciation, texture, microstructure, taste, and flavor of cooked rice. The results showed that parboiling enhances the total Se content by making the bran more difficult to remove. At milling for 40 s, selenomethionine (72.6 %-80.1 %) is predominant Se speciation. Parboiled rice exhibited higher hardness, reduced stickiness, with only minor differences in chewiness. The results regarding cooking quality and microstructure indicated that parboiling restricts starch dissolution during cooking, while the protein remains distributed within starch cell gaps. The parboiling enhances umami and flavor while maintaining the original taste and flavor profile. This work provides valuable insights for application of Se-enriched rice in parboiled rice.