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In order to explore the changes in flavor nucleotide-related compounds in low-salt pickled potherb mustard during storage and transportation, a high-performance liquid chromatography (HPLC) method was established to analyze the changes in the contents of flavor nucleotide-associated substances in low-salt pickled potherb mustard during storage at (25 ± 5) ℃ (J-25), (4 ± 1) ℃ (J-4), and (25 ± 5) ℃ after sterilization (M-25) or (4 ± 1) ℃ after sterilization (M-4) were analyzed. Moreover, the changes in sensory quality were monitored. The results showed that 12 compounds related to flavor nucleotides were effectively separated within 33 min. Both sterilization and cold storage inhibited the deterioration of sensory quality and flavor nucleotide-associated substances, and their combination was more effective than either alone. The contents of adenosine triphosphate (ATP) and inosine monophosphate (IMP) in group M-4 were 29.7% and 66.4% of the initial values after 60 days, respectively, and the sensory quality was still acceptable. The total amount of ATP-related compounds in pickled potherb mustard stored at (25 ± 5) ℃ increased first and then decreased rapidly, and the sensory acceptance period of group J-25 was only 9 days. Both sterilization and cold storage effectively inhibited the changes of flavor nucleotides including adenosine monophosphate (AMP), guanosine monophosphate (GMP), cytidine monophosphate (CMP), uridine monophosphate (UMP) in pickled potherb mustard, and the total amount of these four flavor nucleotides in group M-4 was as high as 4.30 mg/100 g at the end of storage. Microbial metabolism in pickled potherb mustard and high temperatures accelerated the deterioration of flavor nucleotide-related compounds during storage, while sterilization and cold storage were beneficial to the maintenance of flavor nucleotide-associated compounds. The results of this study provide theoretical support for the processing and storage of low-salt pickled potherb mustard.

The performance and phase-separated microstructures of epoxy asphalt binders greatly depend on the concentration of epoxy resin or bitumen. In this paper, the effect of the epoxy resin (ER) concentration (10–90%) on the viscosity, thermo-mechanical properties, and phase-separated morphology of warm-mix epoxy asphalt binders (WEABs) was investigated using the Brookfield rotational viscometer, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and laser scanning confocal microscopy (LSCM). Due to the high reactivity of epoxy resin, the viscosity of WEABs increases with time. Furthermore, the initial viscosity of WEABs decreases with the ER concentration. Depending on the ER concentration, the viscosity–time behavior of WEABs is divided into three stages: slow (10–40%), fast (50–80%), and extremely slow (90%). In the slow stage, the viscosity slightly increases with the ER concentration, while the fast stage shows an opposite trend. DSC and DMA results reveal that WEABs with 10–80% ER exhibit two glass transition temperatures (Tgs) for cured epoxy resin and bitumen. Moreover, the Tgs of epoxy resin and bitumen increase with the ER concentration. However, WEAB with 90 % ER has only one Tg. LSCM observation shows that phase separation occurs in all WEABs. For WEABs containing 10–40% ER, spherical epoxy particles act as the discontinuous phase and disperse in the continuous bitumen phase. However, in WEABs with 50–90% ER, phase inversion takes place. Contrarily, bitumen particles disperse in the continuous epoxy phase. The damping properties of WEABs with the continuous epoxy phases increase with the ER concentration, while the crosslinking density shows an opposite trend. The occurrence of phase inversion results in a sharp increase in the tensile strength of WEABs. For WEABs with the continuous epoxy phases, the elongation at break increases with the ER concentration. The toughness first increases and then decreases with the ER concentration. A maximum toughness value shows at 70% ER. [ABSTRACT FROM AUTHOR]

Waterborne polyurethane asphalt emulsion (WPUA) is an environmentally friendly bituminous material, whose performance is highly dependent on the phase structure of the continuous phase. In this paper, WPUAs in the vicinity of phase inversion were prepared using waterborne polyurethane (WPU) and asphalt emulsion. The chemical structures, thermal stability, dynamic mechanical properties, phase-separated morphology and mechanical performance of WPUAs were studied. Fourier-transform infrared (FTIR) spectra revealed that there are no –NCO bonds in either the pure WPU or WPUAs. Moreover, the preparation of WPUA is a physical process. The addition of WPU weakens the thermal stability of asphalt emulsion. WPU improves the storage modulus of asphalt emulsion at lower and higher temperatures. The glass transition temperatures of the WPUA films are higher than that of the pure WPU film. When the WPU concentration increases from 30 wt% to 40 wt%, phase inversion occurs; that is, the continuous phase shifts from asphalt to WPU. The WPUA films have lower tensile strength and toughness than the pure WPU film. However, the elongations at break of the WPUA films are higher than that of the pure WPU film. Both the tensile strength and toughness of the WPUA films increase with the WPU concentration. Due to the occurrence of phase inversion, the elongation at break, tensile strength and toughness of the WPUA film containing 30 wt% WPU are increased by 29%, 250% and 369%, respectively, compared to the film with 40 wt% WPU. [ABSTRACT FROM AUTHOR]

Thermosetting polymers have higher heat resistance, chemical resistance, mechanical characteristics and structural integrity than thermoplastic polymers due to their three-dimensional networks of covalent bonds. The current status and challenges in the field of thermosetting polymer modified asphalts are reviewed in this article. Firstly, classification and application of thermosetting polymers are briefly introduced, and modification approaches of polymer modified asphalts are compared. Crucial factors in selecting polymers for asphalt modification are then analyzed. Further, the cure mechanisms, preparation methods and properties of thermosetting polymers, including epoxy resin, polyurethane, polyurea, unsaturated polyester resin, phenolic resin, furan resin and amino resin, for asphalt modification are discussed. Especially, the effect of components of epoxy resin and polyurethane on the properties of modified asphalts is described. To develop eco-friendly and sustainable asphalt materials, this article also reviews the use of bio-based thermosetting polymers, including epoxy resin, polyurethane and phenolic resin, in asphalt modification. Finally, self-healing and recyclable thermosetting polymer modified asphalts are highlighted as promising solution to the challenges of healability and recyclability of thermosetting polymers in asphalt modification after long-term service. [ABSTRACT FROM AUTHOR]

This paper deals with the impact of polymer loading on the microstructure, viscosity, thermal properties and mechanical performance of recycled polyethylene (rPE) modified epoxy asphalt binder. With this aim, rPE was used as a modifier to improve the toughness of a hot-mix epoxy asphalt binder. rPE particles were found to be highly swollen by the asphalt. Double phase separation was observed in rPE modified epoxy asphalt binders: asphalts dispersed in the continuous epoxy phase and rPE particles distributed in the discontinuous asphalt phase. The viscosity of epoxy asphalt binders increased with more rPE contents but the allowable construction time for pavement remained long. Results revealed that the thermal stability of epoxy asphalt binders was slightly improved with the addition of rPE. Furthermore, rPE lowered the glass transition temperature and increased the storage modulus at the rubbery state. All rPE modified epoxy asphalt binders performed better damping behaviours. In addition, at low rPE concentrations, the mechanical properties of epoxy asphalt binders were improved while at rPE loading higher than 2%, the results were opposite. [ABSTRACT FROM AUTHOR]

The olecranon honey peach is China's national geographic identification product because of its crisp texture and high sweetness. In recent years, new field management practices have been developed. In this study, fruits ('SJH') grown through new planting methods, i.e., black bags combined with bio-organic fermentation fertilizer, were compared with those ('SBY') grown by conventional planting methods, i.e., using a chemical fertilizer without bagging, to determine their effects on improving fruit quality. At maturity, the 'SJH' was significantly higher than 'SBY' in terms of weight, hardness, and sugar content by 14.43%, 19.55% and 9.66%, respectively. RNA sequencing (RNA-seq) technology analysis was performed on 'SJH' and 'SBY' to identify the main regulatory pathways involved in fruit development, especially focusing on cell-wall biogenesis and sugar metabolism. We identified a total of 1660 differentially expressed genes (DEGs) in 'SJH' and 5673 genes in 'SBY' throughout the development. A clustering analysis of DEGs revealed that the expression patterns of key genes involved in cell-wall biogenesis and sugar metabolism pathways in 'SJH' differed from those in 'SBY', such as cellulose synthase-like protein D (CS-LPD), sucrose-phosphate synthase (SPS) and sucrose synthase (SUS). The new cultivation technology promoted soluble sugar accumulation and cell-wall synthesis through molecular regulation, which improved the sweetness and sensory quality of the fruit. These findings contribute towards to the development of novel ideas for the better cultivation of peaches and provide a deeper investigation into the molecular mechanism of their development. [ABSTRACT FROM AUTHOR]