The effects of storage temperature on the physicochemical properties and qualities of red brown rice were investigated in this study. The samples were vacuum-packed in nylon/polyethylene pouches and stored at 15 °C, 25 °C and 35 °C for 12 weeks. The moisture content decreased as storage time was prolonged. Rice stored at 15 °C and 25 °C had a lower falling range of water content compared to the samples stored at 35 °C. Free fatty acid values increased fastest when samples were stored at a high temperature, and the rise can be effectively delayed at low temperatures. The pH of residual cooking water and adhesiveness decreased, while the heating water absorption rate and hardness increased during storage for red and brown rice. Low-field nuclear magnetic resonance results indicate that water molecules migrated, the binding force of H protons became stronger and the bonds between molecules became closer with increased storage duration. Temperature had an obvious correlation with starch granules and protein structure, characterized by a scanning electron microscope and Fourier transform infrared spectroscopy. Low temperatures significantly retarded those changes. The results indicate that storage temperature is a vital factor affecting the physicochemical properties and qualities of red brown rice and provided reference and theoretical basis for the actual storage of red brown rice.
22 August 2022 in International Journal of Biological Macromolecules
An optical tweezers directed parallel DNA oligonucleotide synthesis methodology is described in which controlled pore glass (CPG) beads act as solid substrates in a two-stream microfluidic reactor. The reactor contains two parallel sets of physical confinement features that retain beads in the reagent stream for synthetic reaction but allow the beads to be optically trapped and transferred between the reagent and the inert streams for sequence programming. As a demonstration, we synthesized oligonucleotides of target sequence 25-nt, one deletion and one substitution using dimethoxytrityl (DMT) nucleoside phosphoramidite chemistry. In detecting single-nucleotide mismatches, fluorescence in situ hybridization of the bead-conjugated probes showed high specificity and signal-to-noise ratios. These preliminary results suggest further possibilities of creating a novel type of versatile, sensitive and multifunctional reconfigurable one-bead one-compound (OBOC) bead array.