Cell wall modification during development of mealy texture in the stony-hard peach “Odoroki” treated with propylene

The melting peach cultivar “Akatsuki” [Prunus persica L. Batsh] develops melting texture during ripening, but the stony-hard peach cultivar “Odoroki”, softens and develops a mealy texture when treated with propylene. Cell wall polysaccharides were fractionated as 1,2-diaminocyclohexanetetraacetic acid (CDTA)-, Na₂CO₃-, NaOH-soluble fractions, or the cellulosic residues that remained after solvent extraction. Size-exclusion chromatography of the CDTA-soluble fraction revealed a limited depolymerization of polyuronides in mealy “Odoroki” fruit, accompanying a lower level of endo-polygalacturonase (endo-PG) and a higher level of exo-PG activities compared to melting “Akatsuki” fruit. “Akatsuki” fruit showed increases in the arabinose, galactose and rhamnose contents in the CDTA-soluble fraction. These neutral sugars decreased in the Na₂CO₃-soluble and cellulosic residue fractions during ripening. Similar changes were observed for neutral sugars other than arabinose during softening in mealy “Odoroki” fruit. Arabinose content did not increase in the CDTA-soluble fraction of “Odoroki” fruit; however, arabinose content decreased in the Na₂CO₃-soluble fraction and in the cellulosic residue as observed for “Akatsuki” fruit. A significant increase in α-l-arabinofuranosidase activity, about 10 times higher than for “Akatsuki” fruit, was observed in propylene-treated mealy “Odoroki” fruit. Differences in ripening-associated metabolic changes in the cell walls of these peach cultivars seem to be related to their differences in texture.     

Relationship between the water molecules in fish-meat gel and the gel structure

To elucidate the structure of the network of the water retention mechanism of fish-meat gel, the microscopic relationship between the water content and viscoelasticity was investigated, and the specific surface area (S) where the water molecules are adsorbed was also measured. The gel structures of fish-meat, actomyosin (AM), and myosin (M) were investigated. In the fish-meat gel, as the water content increased, the number of network chains (??) decreased and the molecular weight between the cross-linking points (M _e) increased. At 10?% salinity and approximately 79?% moisture, ?? decreased to a minimum and M _e began to increase remarkably. In addition, when the moisture increased to 78?%, S increased about 1.5 times and the elasticity decreased significantly, indicating that this level of water content is the limit for sufficiently forming a gel structure in fish-meat gel. In the AM and M gels, M _e and S were similar to those observed in the fish-meat gels. When the moisture content increased, they also increased, regardless of the salt concentration. This result suggests that the size of the network was enlarged or that the network chains were cleaved.     

Transferase activity of GhCesA2 (putative cotton cellulose 4- β -glucosyltransferase) expressed in Pichia pastoris

GhCesA2 is a cotton (Gossypium hirsutum) homologue of the bacterial cellulose synthase gene that encodes cellulose 4--glucosyltransferase. The central catalytic region of GhCesA2 was expressed as a soluble protein in the methylotrophic yeastPichia pastoris. The molecular size of the recombinant protein was 100kDa, which decreased to 85 kDa after treatment with endoglycosidase H. The recombinant GhCesA2 catalyzed transfer of glucose from UDP-glucose into unknown products in the presence of an extract of cotton hypocotyls, but the products were not-1,4-glucan.     

Pharmaceuticals in Rivers of Two Regions with Contrasted Socio-Economic Conditions: Occurrence, Accumulation, and Comparison for Ukraine and France

The goal of our study was to identify pharmaceuticals, their potential sources and consumption level in two different socioeconomic and geographical regions??Bordeaux, France and Kharkiv, Ukraine. These substances were monitored in rivers water during contrasted seasonal conditions with application of passive samplers. The 21 pharmaceuticals (psychiatric drugs: alprazolam, amitriptyline, diazepam, fluoxetine, nordiazepam, carbamazepine, bromazepam; analgesics: aspirin, paracetamol; broncholidator: clenbuterol, salbutamol, terbutaline; non-steroidal anti-inflammatory drug: diclofenac, ibuprofen, ketoprofen, naproxen; lipid regulator: gemfibrozil; stimulants: caffeine, theophylline) were identified in sites upstream and downstream of urban areas and discharge of wastewaters. Caffeine, carbamazepine, and diclofenac were relatively abundant into the surface water and could be considered as potential anthropogenic markers of wastewater discharges into rivers. A mass balance modeling has been applied to calculate approximate consumption rates for carbamazepine, diclofenac, and caffeine in both regions to assess socio-economic factors linked with pharmaceuticals behavior.