Improving the gel properties of Ficus pumila Linn. pectin by incorporating deacetylated konjac glucomannan.

To improve the gelation behaviour of pectin, the effect of deacetylated konjac glucomannan (DKGM) with various deacetylation degrees (27.44 %, 44.32 %, 60.25 %, and 71.77 %) on the heat-induced gel characteristics of Ficus pumila Linn. pectin was studied. The hardness, chewiness, and adhesiveness of the gel increased as the degree of deacetylation increased from 27.44 % to 60.25 %, but decreased at 71.77 %. Additionally, DKGM addition resulted in higher apparent viscosity and non-Newtonian fluid behaviour in the composite gel. The incorporation of DKGM into the gel matrix strengthened the gel structure by promoting hydrogen bond formation and shortening relaxation time compared to the control. Scanning electron microscopy images revealed that the densification of the pectin gel network increased as the degree of deacetylation of konjac glucomannan rose from 27.44 % to 60.25 %, but then loosened when it exceeded 71.77 %. As the degree of deacetylation increased, the hydrophobic interaction between pectin and DKGM increased. Overall, the addition of DKGM effectively modulated the gel properties of Ficus pumila Linn. pectin, thus broadening its industrial application on different gel products.

Effects of konjac glucomannan with different degrees of deacetylation on the properties and structure of wheat gluten protein.

The properties and structure of gluten protein with different deacetylation degrees of konjac glucomannan (KGM) were investigated, in an attempt to improve the quality of gluten protein in flour products. Results showed that deacetylated KGM (DKGM) could improve the textural properties and enhance the thermal stability of gluten protein. DKGM increased the water holding capacity and shortened the T2 relaxation time of gluten after removing some acetyl groups. As the deacetylation degree increased, the hardness and adhesiveness of gluten gels gradually increased, while the springiness decreased. In addition, the presence of DKGM promoted the conversion from free sulfhydryl to disulfide bonds and increased the ß-sheet content in gluten protein. The low-deacetylation KGM decreased the surface hydrophobicity and fluorescence intensity of gluten protein, and the microstructures of gluten gels became more compact. Compared with gluten protein-KGM complex gel, the degradation temperature of gluten protein-DKGM complex gels was observed to increase by >3 °C. Overall, the low-deacetylation KGM was beneficial for improving the physicochemical properties and maintaining the network structure of gluten protein. This study provides valuable references and practical insights to improve gluten quality in the flour industry.

Use of ozone oxidation in combination with deacetylation for improving the structure and gelation properties of konjac glucomannan.

In this study, oxidized deacetylated konjac glucomannans with different degrees of oxidation were prepared by a combination of deacetylation and ozone oxidation. Carboxyl groups were found to be introduced into the modified konjac glucomannan while acetyl groups were removed. The backbone, branched chains, and crystal structure of modified konjac glucomannan were not significantly affected. The whiteness was enhanced to 97-99 % and the thermal degradation temperature was up to 250 °C after modification. The solubility of the modified konjac glucomannan (oxidized for 60 min) was significantly increased to 84.56 % (p < 0.05), while its viscosity and swelling power were notably decreased owing to the changes in molecular weight (from 106 to 104) and functional groups. Rheological analysis showed that oxidized deacetylated konjac glucomannan has the ability to form soft-textured gels and the potential to develop dysphagia foods. Future studies should focus on the gelation mechanisms of oxidized deacetylated konjac glucomannan.

Chromogenic Visualization of Single RNA Molecules In Situ with Duplex Capability by Rolling Circle Amplification with Alkaline Phosphatase.

Visualizing spatial patterns of gene expression by optical microscopy at single-molecule resolution represents a long-standing challenge for imaging and molecular engineering technologies. In this study, we developed a method for visualizing mRNA with duplex capability by optical microscopy using rolling circle amplification with streptavidin-modified alkaline phosphatase (SA-ALP) to provide highly selective and sensitive RNA detection. ALP-based RNA detection provides comparable sensitivity and specificity to fluorescence-based in situ assays and similar performance to the current RNAscope technique for single-molecule RNA detection, but with improved ease of operation. This versatile and relatively user-friendly method of single-molecule RNA visualization can also overcome common problems of background interference. Our findings show that the red spots generated by the Fast Red staining in situ are readily quantified by image analysis, even in samples with heavy melanin deposition, supporting the clinical translation of this assay to improve diagnostic assays for recalcitrant tissues. This system was adaptable for duplex assays with multiple probes and multiple stains, which is ALP with horseradish peroxidase to produce red and brown signals to simultaneously visualize two different RNA targets. The duplex assay can be successfully applied to quantify mRNA expression from two genes in situ within single cells and multiple cell types. With the advantages of high sensitivity and low hardware requirements, this versatile and user-friendly method of RNA visualization may enable low-resource institutions to conduct previously inaccessible diagnostic or research questions about the in situ expression and distribution of RNAs at single-molecule resolution.

Systematic Genome-Wide Study and Expression Analysis of SWEET Gene Family: Sugar Transporter Family Contributes to Biotic and Abiotic Stimuli in Watermelon.

The SWEET (Sugars Will Eventually be Exported Transporter) proteins are a novel family of sugar transporters that play key roles in sugar efflux, signal transduction, plant growth and development, plant-pathogen interactions, and stress tolerance. In this study, 22 ClaSWEET genes were identified in Citrullus lanatus (Thunb.) through homology searches and classified into four groups by phylogenetic analysis. The genes with similar structures, conserved domains, and motifs were clustered into the same groups. Further analysis of the gene promoter regions uncovered various growth, development, and biotic and abiotic stress responsive cis-regulatory elements. Tissue-specific analysis showed most of the genes were highly expressed in male flowers and the roots of cultivated varieties and wild cultivars. In addition, qRT-PCR results further imply that ClaSWEET proteins might be involved in resistance to Fusarium oxysporum infection. Moreover, a significantly higher expression level of these genes under various abiotic stresses suggests its multifaceted role in mediating plant responses to drought, salt, and low-temperature stress. The genome-wide characterization and phylogenetic analysis of ClaSWEET genes, together with the expression patterns in different tissues and stimuli, lays a solid foundation for future research into their molecular function in watermelon developmental processes and responses to biotic and abiotic stresses.