RESUMO
Sunlight exposure of grape clusters is frequently reported to influence grape aromas greatly. Among them, the effects of full shading (FS) of clusters on fruit quality and volatile compounds in grape berries has scarcely been investigated. In the present study, the effects of FS from véraison to ripeness on fruit quality and volatile compounds in Cabernet Sauvignon grapes were studied. The results showed that FS treatment reduced fruit size and berry weight, delayed fruit maturity, and decreased the contents of anthocyanins, phenols, and tannins in grape berries. In addition, volatile compounds in grape berries were analyzed, and 55 and 53 volatile compounds were detected in the control (CK) and FS groups, respectively. The results indicated that the concentrations of straight-chain fatty aldehydes, straight-chain fatty alcohols, straight-chain fatty acids, and branched-chain fatty acids, norisoprenoids, and total concentration of volatile compounds were all higher in FS group than in CK group. Specifically, FS treatment had significant promoting effects on the concentrations of ß-damascenone, terpineol, 2-ethyl-1-hexanol, and 2-hexenal, and remarkably decreased the concentrations of geranial, benzeneacetaldehyde, neral, and ethyl acetate. Partial least squares-discriminant analysis (PLS-DA) revealed a clear separation between the control (CK) and FS groups, and showed that 2-hexenal and hexanal were the main characteristic aroma compounds in the FS group. Moreover, an increase in the intensity of fruity, herbaceous, floral, and mushroom aromas was recorded in FS grapes. This study provides new insights into the effects of the exclusion of sunlight exposure on volatile compound accumulation in grape berries.
RESUMO
In recent years, the ethylene-mediated ripening and softening of non-climacteric fruits have been widely mentioned. In this paper, recent research into the ethylene-mediated ripening and softening of non-climacteric fruits is summarized, including the involvement of ethylene biosynthesis and signal transduction. In addition, detailed studies on how ethylene interacts with other hormones to regulate the ripening and softening of non-climacteric fruits are also reviewed. These findings reveal that many regulators of ethylene biosynthesis and signal transduction are linked with the ripening and softening of non-climacteric fruits. Meanwhile, the perspectives of future research on the regulation of ethylene in non-climacteric fruit are also proposed. The overview of the progress of ethylene on the ripening and softening of non-climacteric fruit will aid in the identification and characterization of key genes associated with ethylene perception and signal transduction during non-climacteric fruit ripening and softening.
RESUMO
Microplastics have been identified as an emerging pollutant that poses a risk to the aquatic environment, and it is a challenge to find a suitable removal process. Electrocatalytic oxidation (ECO) technology has shown promising performance in removing various persistent organic pollutants. In this study, we prepared a new anode for removing polystyrene microplastics (PS MPs) by ECO. Ti/La-Sb-SnO2 electrodes doped with the rare earth element La as the active layer were synthesized to enhance the electrocatalytic activity. The lifespan of the electrode was improved by doping Mn, Co, or Ru as an intermediate layer modification between the titanium (Ti) substrate and the La-Sb-SnO2 active layer, respectively. The experimental results indicated that the addition of three types of intermediate layers led to different degrees of decrease in the catalytic activity of the electrode and the degradation performance of PS MPs. The addition of the Co intermediate layer had a negligible effect on the catalytic activity and performance of the Ti/La-Sb-SnO2 anode for PS degradation. In addition, the electrode lifespan with Co intermediate layer was significantly prolonged, which was 4.54, 2.38, and 1.19 times higher than the electrode without intermediate layer and the electrode with Ru and Mn intermediate layer, respectively. Therefore, Co was determined to be the optimal choice as the intermediate layer, and the production technique for the Ti/La/Co-Sb-SnO2 anodes was carefully adjusted. The degradation efficiency of PS MPs was optimized at a heat treatment temperature of 400 °C and a Sn: Co material ratio of 5:1, with a removal rate of 28.0 %. The ECO treatment also resulted in more pronounced changes in the structure and functional groups of the MPs. Various alkyl cleavage and oxidation products were detected after the treatment, suggesting that the oxidant (hydroxyl radicals) strongly interacted with the MPs, leading to their degradation. Overall, this work provided a new insight into removing MPs in water through the use of modified electrodes.