Search Results (8)

Cold storage is widely used for the postharvest preservation of fruits and vegetables; however, okra, as a tropical vegetable, is susceptible to chilling injury under low-temperature storage conditions, leading to quality deterioration, reduced nutritional value, and significant economic losses. Nitric oxide (NO), as an important signaling molecule, plays a crucial role in the postharvest preservation of fruits and vegetables. To investigate the effects of different concentrations of nitric oxide on the postharvest quality of okra under cold storage, fresh okra pods were treated with sodium nitroprusside (SNP), a commonly used NO donor, at concentrations of 0 (control), 0.5 (T1), 1.0 (T2), 1.5 (T3), and 2.0 mmol·L⁻¹ (T4). The results showed that low-concentration NO treatment (T1) significantly reduced weight loss, improved texture attributes including hardness, springiness, chewiness, resilience, and cohesiveness, and suppressed the increase in adhesiveness. T1 treatment also effectively inhibited excessive accumulation of cellulose and lignin, thereby maintaining tissue palatability and structural integrity. Additionally, T1 significantly delayed chlorophyll degradation, preserved higher levels of soluble sugars and proteins, and enhanced the activities of key antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), contributing to improved oxidative stress resistance and membrane stability. In contrast, high-concentration NO treatments (T3 and T4) led to pronounced quality deterioration, characterized by accelerated membrane lipid peroxidation as evidenced by increased malondialdehyde (MDA) content and relative conductivity, and impaired antioxidant defense, resulting in rapid texture degradation, chlorophyll loss, nutrient depletion, and oxidative damage. These findings provide theoretical insights and practical guidance for the precise application of NO in extending shelf life and maintaining the postharvest quality of okra fruits. Full article

This study analyzed temperature and yield data from 34 meteorological stations in Heilongjiang Province during 1961–2020. Four climate averages (P₁, P₂, P₃, and P₄) were determined based on their respective time distributions (1961–1990, 1971–2000, 1981–2010, and 1991–2020). The national standard temperature anomaly index was used to identify delayed chilling damage in rice cultivation compared to these climate averages. Climate tendency rate analysis, Mann–Kendall detection, and linear regression methods were employed to examine the relationship between temperature anomaly and rice yield from May to September. The results showed that there were noticeable differences in recognizing delayed chilling damage across different climate averages from 1961 to 2020. The average duration of chilling damage under P₁, P₂, P₃, and P₄ was, respectively, estimated as 8.5 years, 13.3 years, 21.4 years, and 30.9 years, with severe cold damage accounting for a significant portion (68.2–76.0%) of the total chilling damage period. The occurrence of severe cold damage increased significantly over time while light and moderate cold damage did not show a clear increasing or decreasing trend. Based on the test results, P₃ was found to be the most suitable climate average for identifying delayed chilling damage in rice cultivation from 1961 to 2020. Moreover, the incidence of chilling damage revealed declining trend over time. There was a high incidence of chilling damage in the 1960s and 1970s, followed by a decrease from the 1980s to the mid 1990s, and finally a low-incidence period after the mid-1990s. Spatially, the western regions experienced greater occurrence of chilling damage than the eastern regions. Additionally, there was a highly significant positive correlation (p < 0.01) between temperature anomalies from May to September and relative meteorological yield of rice. As temperature anomalies decreased during this period, there was an observed downward trend in relative meteorological yield of rice, indicating that delayed cold injury had a negative impact on rice production. Full article

Tomato fruit (Solanum lycopersicum L.) has a very brief storability, displaying chilling injury (CI) when stored in cold conditions used to delay ripening. For this reason, in this study, different concentrations (10, 50, and 100 mg L⁻¹) of chlorogenic acid (ChA) were assayed to evaluate its effectiveness in maintaining fruit quality traits and mitigating CI symptoms in tomatoes. Our results showed that ChA treatments effectively delayed weight loss and maintained fruit firmness, with optimal results observed at 50 mg L⁻¹. In general, higher concentrations did not result in significant quality improvements. Additionally, ChA-treated tomatoes exhibited reduced values in malondialdehyde (MDA) content and electrolyte leakage (EL), indicating improved membrane integrity and reduced oxidative damage. ChA treatments also maintained a higher total phenolic content (TPC) during storage, with significant levels of individual polyphenols such as rutin, neochlorogenic acid, and p-coumaric acid, suggesting enhanced antioxidant capacity and better preservation of fruit quality. This is the first time the potential of ChA to reduce CI has been evaluated in any fruit species, and its impact in tomato ripening is shown to uphold fruit quality during cold storage, prolonging the storability of tomatoes. In particular, we highlight its natural origin and effectiveness as a postharvest treatment. Full article

Spain is the world’s leading producer of cherimoya, a climacteric fruit highly appreciated by consumers. However, this fruit species is very sensitive to chilling injury (CI), which limits its storage. In the present experiments, the effects of melatonin applied as dipping treatment on cherimoya fruit CI, postharvest ripening and quality properties were evaluated during storage at 7 °C + 2 days at 20 °C. The results showed that melatonin treatments (0.01, 0.05, 0.1 mM) delayed CI, ion leakage, chlorophyll losses and the increases in total phenolic content and hydrophilic and lipophilic antioxidant activities in cherimoya peel for 2 weeks with respect to controls. In addition, the increases in total soluble solids and titratable acidity in flesh tissue were also delayed in melatonin-treated fruit, and there was also reduced firmness loss compared with the control, the highest effects being found for the 0.05 mM dose. This treatment led to maintenance of fruit quality traits and to increases in the storage time up to 21 days, 14 days more than the control fruit. Thus, melatonin treatment, especially at 0.05 mM concentration, could be a useful tool to decrease CI damage in cherimoya fruit, with additional effects on retarding postharvest ripening and senescence processes and on maintaining quality parameters. These effects were attributed to a delay in the climacteric ethylene production, which was delayed for 1, 2 and 3 weeks for 0.01, 0.1 and 0.05 mM doses, respectively. However, the effects of melatonin on gene expression and the activity of the enzymes involved in ethylene production deserves further research. Full article

There are high levels of damage imposed on persimmon fruit postharvest, especially after storing it in cold storage, which causes chilling injury (CI). To reduce this stress on the fruit, the conventional way is to use chemical treatments. Since there is a limitation in the use of chemical materials, it is necessary to apply non-harmful treatments to decrease chilling injury and maintain the quality of persimmon in cold storage. The aim of this study is to investigate the effects of chitosan-loaded phenylalanine nanoparticles (Cs-Phe NPs) (2.5 and 5 mM) on physiochemical and quality factors of persimmon (Diospyros kaki) during 45 days of storage at 4 °C (38 °F) and evaluate the impact of Cs-Phe NPs on the preserving quality in order to reduce the chilling injury of this fruit. The experiment was conducted using a completely randomized design with three replications. Treatments were applied at 15, 30, and 45 days after storage at 4 °C with ≥90% relative humidity. The size of Cs-Phe NPs was less than 100 nm, approximately. The results showed that application of 5 mM of Cs-Phe NPs delayed the negative effects of chilling stress and enhanced antioxidant capacity, firmness, and total soluble solids of persimmon fruit. Lower H₂O₂ and malonaldehyde (MDA) accumulation along with higher soluble tannin and total carotenoid accumulation in persimmon fruit treated with 5 mM Cs-Phe NPs was also observed. Fruit coated using Cs-Phe NPs in both concentrations (2.5 and 5 mM) showed the highest antioxidant enzyme activity for superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) and the lowest for polyphenol oxidase (PPO) and chilling injury during storage. According to our results, 5 mM of Cs-Phe NPs could be considered as the best treatment under chilling-stress conditions. Full article

Cucumbers have a limited shelf-life, from 10 to 14 days at commercial temperatures with relative humidity (80%). The aim of the work was to evaluate the postharvest physicochemical properties and fungal populations of cucumber treated with sodium tripolyphosphate/titanium dioxide nanoparticles during storage at 10 °C to prolong the shelf-life to 21 days. Cucumber samples treated with chitosan/sodium tripolyphosphate/titanium dioxide nanoparticles (Cu-CHS-TDN-ST) and (Cu-CHS-TDN-ST) were found to be in a well-hydrated state and with a green-colored appearance upon day 21, with excellent quality for consumption. Chitosan coating (Cu-CHS) alone prolonged the cucumber shelf-life for 14 days of storage. The Cu-CHS coating was less evident in reducing the respiration rate of cucumbers on day 14 than both nanocoatings, which were reported at the end of the storage period to be 5.09 and 5.38 mg·kg⁻¹ h⁻¹ for Cu-CHS-TDN-ST and Cu-CHS-TDN, respectively. The Cu-CHS-TDN-ST treatment reduced the loss of ascorbic acid content to 13.17 mg/100 g, delayed chilling injury, and had the highest chlorophyll contents during the whole storage period. The presence of sodium tripolyphosphate with the nanocoating delayed tissue damage. Peroxidase enzyme activity reached the maximum of 54.65 Ug⁻¹ for Cu-CHS-TDN-ST on day 21, followed by Cu-CHS-TDN 50.1 Ug⁻¹. On day 21, the fungal populations of Cu-CHS-TDN samples (3.77 log CFU/g) were more than that of Cu-CHS-TDN-ST (3.15 log CFU/g) against Cu-Control (100 % spoiled). It was noted that the Cu-CHS-TDN-ST and CHS-TDN-ST coating treatments were capable of preserving the cucumber samples’ quality during storage. The addition of sodium tripolyphosphate as a crosslinker for stabilizing the nanoparticle polymers in the coating treatments prolonged the shelf-life and achieved excellent quality for the cucumbers. Full article

Chilling injury, tissue browning, and fungal infection are the major problems of peach fruit during post-harvest storage. In this study, a precise temperature control cold storage with low-temperature fluctuation (LFT) and internal circulation flow system is designed. An ozone (O₃) generator and a (titanium dioxide) TiO₂ photocatalytic reactor were applied to cold storage to investigate the variation of LFT combined with ozone fumigation and a TiO₂ photocatalytic reactor in the efficiency of delaying ripening and maintaining peach fruit quality. Results showed that the temperature fluctuation with the improved control system was only ±0.1 to ±0.2 °C compared with that of ±0.5 to ±1.0 °C in conventional cold storage. LFT significantly reduced the chilling injury of peach fruit during storage. Although LFT combined with fumigation of 200 mg m⁻³ ozone periodical treatment slightly damaged the peach fruit after 40 d of storage, its combination with the TiO₂ photocatalytic system significantly improved the postharvest storage quality of the fruit. This treatment maintained higher titratable acidity (TA), total soluble solids (TSS), better firmness, color, microstructure, and lower decay rate, polyphenol oxidase (PPO) activities, total phenol accumulation, respiratory intensity, ethylene production, and malondialdehyde (MDA) content during 60 d of storage. All the results show that LFT combined with the TiO₂ photocatalytic system might be a promising technology for quality preservation in peach fruit storage. Full article

Given that chilling injury, which involves late spring cold and early autumn freezing, significantly affects maize growth in middle-latitude cold areas, a highly efficient cultivation technique combining suitable planting date (PD) and mulched drip irrigation is being studied to guarantee maize production. A field experiment for medium-mature variety “Xianyu 335” was conducted in 2015 to 2016 in Chifeng, Inner Mongolia, China, to explore the effects of PD on the active accumulated temperature (AAT) distribution and maize growth under mulched drip irrigation. Based on the dates (around May 1) of late spring cold occurring in the area, four PDs were designed, namely, April 20 (MD₁), May 2–3 (MD₂), May 12 (MD₃), and May 22 (MD₄), and a non-film mulching treatment (NM-D₂) was added on the second PD. Results indicated that: (1) the warming effect of film mulching effectively compensated for the lack of heat during the early stages of maize growth. Compared with that in NM-D₂, the soil temperature under mulching in MD₂ for the sowing–emergence and seedling stage increased by 14.3% and 7.6%, respectively, promoting maize emergence 4 days earlier and presenting 5.6% and 9.7% increases in emergence rate and grain yield, respectively; (2) the AAT reduction caused by PD delay was mainly observed in reproductive stage, which reached 96.6 °C for every 10 days of PD delay in this stage; (3) PD markedly affected maize growth process and yield, which were closely related to the chilling injury. The late spring cold slowed down the emergence or jointing for maize (under MD₁ and MD₂), but brought insignificant adverse effect on maize later growth and grain yield (16.1 and 15.9 Mg·ha⁻¹, respectively). While the maize in both MD₃ and MD₄ treatments suffered from early autumn freezing damage at the anthesis–maturity stages, resulting in shortening in reproductive period by 4–8 days and decrease in grain yield by 11.4–17.3% compared with those in MD₁ and MD₂; and (4) taking the typical date (May 1) of late spring cold occurring as the starting point, the grain yield penalty reached 8.5% for every 10 days of PD delay; for every 100 °C of AAT decrease during reproductive stage, the grain yield decreased by 6.1%. The conclusions offer certain reference values for maize cultivation in the same latitude areas with similar ecological environments. Full article