Comprehensive Evaluation of the ‘Shixia’ Longan Quality under Postharvest Ambient Storage: The Volatile Compounds Played a Critical Part

Longan fruit generally undergoes rapid quality deterioration during the postharvest stage, with the manifestation of flavor loss as well as pronounced off-odor production. Nevertheless, the unapparent aroma makes people ignore the odor change in postharvest longan. Sensory analysis serves as an indispensable method combining instrumental detection and the perceptibility of human sensation in a comprehensive evaluation of quality during production and consumption. In this study, we established the evaluating data of the appearance, flavor, taste substances, volatile profiles, and deterioration of ‘Shixia’ longan throughout room-temperature storage using instrument assessment and descriptive measurements. Our results indicated that both the appearance state and the taste condition notably engendered confusion or trouble for consumers to judge under the quality transition period. Conversely, the development of odor was highly consistent with that of quality deterioration. Some unpleasant volatile substances including alcohol (ethanol), acid (acetic acid), and esters (acetic acid methyl ester and ethyl acetate) were probably the cause of off-odor during the storage. The result of the sensory evaluation also presents a more significant relevance between the overall quality and the odor. Generally, the work paved the way to reveal the importance of odor profiles for assessing the comprehensive quality condition of postharvest room-temperature stored longan

Controllable synthesis of silicon/carbon microspheres alternating carbon and silicon shells for high-energy lithium-ion batteries

The poor cycling stability and huge volume change of silicon during the charge/discharge processes have seriously hindered the extensive application. In order to deal with address various challenges, silicon/carbon microspheres (SCM) are designed via nonsynchronous nucleation, hydrothermal coupling method and magnesium thermal reduction method. The silicon/carbon microspheres with two carbon shells (SCM-2) delivers the most enhanced initial charge capacity of 2455 mAh g(-1) at 0.1 C, and reveals the highest specific capacity of 2178 mAh g(-1) after 200 cycles and capacity retention of 98% after 500 cycles at 2 C. The SCM-2//LiCoO2 full cell can maintain high capacity of 159.2 mAh g(-1) and no capacity decay after 500 cycles at 0.1 C. It is demonstrated that the fabrication for silicon/carbon microspheres is a convenient and effective strategy to resolve the practical application silicon anode material in lithium-ion batteries

Controllable synthesis of silicon/carbon microspheres alternating carbon and silicon shells for high-energy lithium-ion batteries

The poor cycling stability and huge volume change of silicon during the charge/discharge processes have seriously hindered the extensive application. In order to deal with address various challenges, silicon/carbon microspheres (SCM) are designed via nonsynchronous nucleation, hydrothermal coupling method and magnesium thermal reduction method. The silicon/carbon microspheres with two carbon shells (SCM-2) delivers the most enhanced initial charge capacity of 2455 mAh g(-1) at 0.1 C, and reveals the highest specific capacity of 2178 mAh g(-1) after 200 cycles and capacity retention of 98% after 500 cycles at 2 C. The SCM-2//LiCoO2 full cell can maintain high capacity of 159.2 mAh g(-1) and no capacity decay after 500 cycles at 0.1 C. It is demonstrated that the fabrication for silicon/carbon microspheres is a convenient and effective strategy to resolve the practical application silicon anode material in lithium-ion batteries

A Comprehensive Analysis of Physiologic and Hormone Basis for the Difference in Room-Temperature Storability between ‘Shixia’ and ‘Luosanmu’ Longan Fruits

Although the effects of phytohormones (mainly salicylic acid) on the storability of longan fruit have been reported, the relationship between postharvest hormone variation and signal transduction and storability remains unexplored. The basis of physiology, biochemistry, hormone content and signalling for the storability difference at room-temperature between ‘Shixia’ and ‘Luosanmu’ longan fruit were examined. ‘Luosanmu’ longan exhibited faster pericarp browning, aril breakdown and rotting during storage. ‘Luosanmu’ pericarp exhibited higher malondialdehyde but faster decreased total phenolics, flavonoid, glutathione, vitamin C, catalase activity and gene expression. Higher H2O2 and malondialdehyde but lower glutathione, glutathione-reductase and peroxidase activities, while higher activities and gene expressions of polygalacturonase, β-galactosidase and cellulose, lower covalent-soluble pectin, cellulose and hemicellulose but higher water-soluble pectin were observed in ‘Luosanmu’ aril. Lower abscisic acid and methyl jasmonate but higher expressions of LOX2, JAZ and NPR1 in pericarp, while higher abscisic acid, methyl jasmonate and salicylic acid together with higher expressions of ABF, JAZ, NPR1 and PR-1 in ‘Luosanmu’ aril were observed. In conclusion, the imbalance between the accumulation and scavenging of active oxygen in ‘Luosanmu’ longan might induce faster lipid peroxidation and senescence-related hormone signalling and further the polymerization of phenolics in pericarp and polysaccharide degradation in aril