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Hydrophilic natural gums have gained increasing attention as food cryoprotectants due to their special functional properties. In this study, the functional properties of Chinese quince seed gum (CQSG), i.e., rheological, textural, emulsifying and foaming properties, were characterized. Effects of gum concentration (0.50–3.00% in w/v) and freezing temperature (−18 °C and −34 °C) were investigated. During freeze–thaw process, there was insignificant change in the flow behavior of the CQSG solution, presumably due either to the random distribution or to the flexibility of the gum molecular chains. After freeze–thaw treatment, the textural properties were stable at low gum concentrations, and the cohesiveness and springiness were relatively stable at high gum concentrations. The hardness and gumminess were enhanced after being frozen at −34 °C and then thawed. The CQSG solutions at all concentrations exhibited enhanced emulsifying and foaming capacities after freeze–thaw treatment, and their stabilities were improved significantly. These results suggest that Chinese quince seed gum can be used as a cryoprotectant in frozen foods.

Sesame paste, usually served as a dressing in some local dishes and the desserts in Southeast Asia and the Middle East, requires mixing with water before consumption to form a thin emulsion of the oil-in-water type. Usually water addition is performed empirically and it is difficult to keep the quality of water-mixed sesame paste consistent. In this study, the rheological behavior of sesame paste with different ratios of sesame paste to added water was investigated. The sesame paste tested contains 59.71% of crude fat and 17% of protein. The ratios of sesame paste to added water (w/v) were 1 : 0.75 (T1), 1 : 1 (T2), 1 : 1.25 (T3), and 1 : 1.5 (T4), respectively. All the samples showed the properties of the viscoelastic solids. The samples T1 and T2 behaved as a pseudoplastic material, whereas the apparent viscosity of T3 and T4 remained almost unchanged with the shear rate increasing. T2 had the moderate area of thixotropy loop (57.32 Pa/s) among the tested samples and scored the highest in the sensory evaluation. Therefore, our study suggested that ratio of sesame paste to added water of 1 : 1 (w/v) is suitable for preparing dressings for different dishes.

Hydrogen peroxide (H2O2) is an important signaling molecule in ethylene-induced stomatal closure in Arabidopsis thaliana. Early studies on the sources of H2O2 mainly focused on NADPH oxidases and cell-wall peroxidases. Here, we report the involvement of polyamine oxidases (PAOs) in ethylene-induced H2O2 production in guard cells. In Arabidopsis epidermal peels, application of PAO inhibitors caused the failure of ethylene to induce H2O2 production and stomatal closure. Results of quantitative RT-PCR analysis and pharmacological experiments showed that AtPAO2 and AtPAO4 transcripts and activities of PAOs were both induced by ethylene. In transgenic Arabidopsis plants over-expressing AtPAO2 and AtPAO4, stomatal movement was more sensitive to ethylene treatment and H2O2 production was also significantly induced. The increased H2O2 production in the transgenic lines compared to the wild-type plants suggests that AtPAO2 and AtPAO4 probably are involved in ethylene-induced H2O2 production. Several factors which induce stomatal closure such as dehydration and high salinity all enhanced the expression of AtPAO2 and AtPAO4 to different degrees. Moreover, GFP-AtPAOs fusion protein localized in the nucleus, cytoplasm, and cell wall of the guard cells. Therefore, our results strongly indicated that PAO is a source of H2O2 generation in Arabidopsis guard cells and plays crucial roles in stomatal movement.

Pharmacological, laser scanning confocal microscopic (LSCM), and spectrophotographic approaches were used to study the roles of hydrogen sulfide (H2S) and nitric oxide (NO) in signaling transduction of stomatal movement in response to ethylene in Vicia faba L. Ethylene treatment resulted in the dose-dependent stomatal closure under light, and this effect was blocked by the inhibitors of H2S biosynthesis in V. faba L. Additionally, ethylene induces H2S generation and increases L-/D-cysteine desulfhydrase (pyridoxalphosphate-dependent enzyme) activity in leaves of V. faba L. Inhibitors of H2S biosynthesis have no effect on the ethylene-induced stomatal closure, NO accumulation, and nitrate reductase (NR) activity in guard cells or leaves of V. faba L. Moreover, the ethylene-induced increase of H2S levels and L-/D-cysteine desulfhydrase activity declined when NO generation was inhibited. Therefore, we conclude that H2S and NO probably are involved in the signal transduction pathway of ethylene-induced stomatal closure. H2S may represent a novel component downstream of NO in the ethylene-induced stomatal movement in V. faba L.

The chemical characteristics, rheological properties and sensory evaluation of nine different brands of the sesame pastes were investigated. The sesame pastes showed a significant difference for the crude fat, protein, crude fibre, total sugars, total ash, moisture content, and acid values (p < 0.05). The fat content ranged from 51.80% to 61.56%, and the protein content varied between 16.08% and 18.97%. All sesame paste samples are pseudoplastic materials. The flow indexes lied between 0.67 and 0.81 for the tested sesame pastes (p > 0.05). The consistency coefficient of the different sesame paste brands varied significantly (p < 0.05), ranging from 4.48 to 24.21 Pa・sn, indicating that the consistency coefficient is a more sensitive parameter for measuring the flow behaviour of foodstuff. The areas of the hysteresis loops of the whitesesame paste of "Haoweisi" brand and the black-sesame paste of "A Yimeng couple" brand were higher than the other sesame pastes, indicating that these two samples were difficult to be restored to their original structures and such restoration required a longer time. Both Storage modulus (G') and loss modulus (G") of the sesame pastes increased with increasing frequency, and G' values were greater than the G" values, exhibiting the typical properties of the viscoelastic solid, the results may provide the valuable reference for choosing the sesame pastes as the spreadable butters or salad dressings, and for further processing. [ABSTRACT FROM AUTHOR]

In order to characterize a specific extracellular 21-kDa calmodulin-binding protein (named: ECBP21) from Angelica dahurica L. suspension-cultured cells, the cDNA coding for the protein has been cloned. Here, Southern blot analysis shows that there are at least two copies of ECBP21 gene in Angelica genome. Using truncated versions of ECBP21 and synthetic peptide in CaM binding assays, we mapped the calmodulin-binding domain to a 16-amino acid stretch (residues 200–215) at the C-terminal region. The ECBP21 was localized in the cell wall area by the immunogold electron microscopy and by GFP labeling method. These results define ECBP21 as a kind of an extracellular calmodulin-binding protein (CaMBP). Furthermore, using Northern blot analysis, we examined the expression dynamics of ecbp21 during the incubation of Angelica suspension-cultured cells and the treatments with some growth regulators. The above studies further provide the molecular evidence for the existence of the gene coding for extracellular CaMBPs and imply a possible role for ECBP21. [ABSTRACT FROM AUTHOR]

The ingestion of lactobacilli is of great importance for the probiotic effect of host gut Peyer's patches (PPs) macrophages. The present study is in time focus on the investigation of the factors determining the ingestion of lactobacilli by PPs macrophages. Physicochemical properties of cell surface and adhesive property of nine Lactobacillus strains were examined in the present work. The association of the bacteria with PPs macrophage was checked with macrophage monolayers on coverslips. The influence of lactobacilli on macrophages phagocytic capacity was also investigated with a neutral red uptake assay in vitro. The results show that the macrophages could ingest lactobacilli in a strain dependent manner, and the most ingested strain is L. plantarum Lp6 compared to other tested strains, which displayed strain specific enhancement on the phagocytic activity of PPs macrophages. And there is no correlation between the physicochemical or adhesive properties of the cell surface and the ingestion. The association of L. plantarum Lp6 with PPs macrophage could be decreased by Protease K treatment. Surface proteins of L. plantarum Lp6 could promote the ingestion of fluorescent latex beads by PPs macrophages. In conclusion, the hydrophobicity of the cell surface might not be the key factor determining the association of lactobacilli with PPs macrophages. Cell surface proteins are the media for the binding L. plantarum Lp6 to macrophages. [ABSTRACT FROM AUTHOR]