Postharvest Storage Of Vegetables Research Articles

Effects of Hydrogen Sulfide on Sugar, Organic Acid, Carotenoid, and Polyphenol Level in Tomato Fruit.

Hydrogen sulfide (H2S) is known to have a positive effect on the postharvest storage of vegetables and fruits, but limited results are available on its influence in fruit flavor quality. Here, we presented the effect of H2S on the flavor quality of tomato fruit during postharvest. H2S decreased the content of fructose, glucose, carotene and lycopene but increased that of soluble protein, organic acid, malic acid and citric acid. These differences were directly associated with the expression of their metabolism-related genes. Moreover, H2S treatment raised the contents of total phenolics, total flavonoids and most phenolic compounds, and up-regulated the expression level of their metabolism-related genes (PAL5, 4CL, CHS1, CHS2, F3H and FLS). However, the effects of the H2S scavenger hypotaurine on the above flavor quality parameters were opposite to that of H2S, thus confirming the role of H2S in tomato flavor quality. Thus, these results provide insight into the significant roles of H2S in tomato fruit quality regulation and implicate the potential application of H2S in reducing the flavor loss of tomato fruit during postharvest.

Review on effect of postharvest illumination by fluorescent and ultraviolet light waves on the quality of vegetables

AbstractPostharvest illumination is an emerging nonthermal preservation technique used to preserve the quality of vegetables. This review aimed to provide an insight into the effect, importance, and limitations of postharvest illumination by fluorescent and ultraviolet (UV) light on the physical and nutraceutical properties of vegetables. It presents the current information on the postharvest application of these two lightings based on the vegetable species. According to the existing studies, both photoperiod and continuous (low‐intensity) fluorescent lighting treatments were beneficial more toward preserving the quality (delaying senescence and deterioration) of postharvest vegetables, mainly leafy vegetables. However, inconsistent results are also possible with the light quality (intensity and duration) on the postharvest fluorescent lighting treatment. According to gathered information, both UV‐B and UV‐C postharvest irradiation has been beneficial in delaying senescence and chlorophyll degradation and inducing bioactive compounds accumulation in some vegetable species. UV‐C application is appeared to have a relatively steady effect on the postharvest storage of vegetables. But UV‐B irradiation effect on the postharvest quality of vegetables was appeared to be dose dependent and not stable. In conclusion, it is important to consider vegetable (species, cultivar, harvesting age, and intact or fresh‐cut), previous treatments/conditions, optimum postharvest lighting condition (illumination source, dose, intensity, and duration), and the storage condition (temperature and relative humidity) for a successful implementation of postharvest illumination. More research is required to explore the postharvest application of fluorescent and UV (UV‐A, UV‐B, UV‐C) irradiation on vegetables.Practical ApplicationsMultiple research approaches have been taken to preserve the postharvest quality of vegetables while minimizing chemical preservation techniques. Postharvest illumination is a nonchemical preservation technique that has attained more interest due to the advantages it holds, such as being highly efficient and residue‐free. Fluorescent and UV lighting on harvested leafy and non‐leafy vegetables are beneficial in delaying senescence and chlorophyll degradation, preserving nutritional quality, and extending the shelf life. With the accessibility of more research data and innovative strategies, the future of postharvest illumination of fluorescent and UV maybe steer toward implementation on commercial scale vegetable production (e.g., during storage and/or transportation).

Analysis of virulence and genetic variability of Alternaria alternata associated with leaf spot disease in potato plants in Iran

Leaf spot disease in potato is caused by <em>Alternaria alternata</em> (Fr.) Keissler, an opportunistic pathogen that infests many agricultural crops worldwide in the field and during postharvest storage of vegetables and fruits. <em>Alternaria alternata</em> is associated with leaf spot disease in potato in Iran. Thus, there is a need to investigate the virulence and genetic variability of Iranian <em>A. alternata</em> isolates to facilitate the development of appropriate management strategies. In the present study, we analyzed a total of 28 isolates obtained from the main potato-growing regions of Iran, including the Ardebil, Hamedan, Isfahan, and Fars provinces. The pathogens were characterized based on sequence analysis of the genes encoding glyceraldehyde-3-phosphate dehydrogenase (<em>gpd</em>), plasma membrane ATPase, <em>Alternaria</em> allergen a 1 (Alt a1), calmodulin, and actin. In addition, random amplified polymorphic DNA (RAPD), intersimple sequence repeat (ISSR), and virulence studies were performed. Phylogenetic analysis of the combined dataset indicated that the five representative isolates were grouped with the subcluster comprising <em>A. alternata</em>. RAPD and ISSR analyses clustered the 28 <em>A. alternata</em> isolates into different groups with no correlation with their corresponding geographical origins. Results of the pathogenicity assay indicated that all <em>A. alternata</em> isolates were pathogenic against potato. However, the <em>A. alternata</em> isolates showed high variability in terms of virulence.

Effect of Vacuum Pre-cooling on Quality Properties of Broccoli after Harvest Compared with Other Conventional Cooling Methods

Vacuum pre-cooling technology has potential to be used in post-harvest storage of vegetables by removing field heat rapidly. In the current study, the efficiencies of different cooling methods (vacuum cooling, cooling water and cold room) and the quality properties of broccolis with pre-cooling treatments were compared. The results indicated that vacuum cooling treatment was the most effective method to extend the shelf life of post-harvest broccolis through the investigation of cooling rate, respiration rate, chlorophyll, vitamin C, reducing sugar, and sensory properties. Besides, by means of applying water-spraying on broccolis during vacuum cooling process, the weight loss was significantly reduced which was slightly higher than that resulted by the other two cooling methods and it did not negatively affect the quality of broccolis. Consequently, vacuum pre-cooling treatment can be applied on vegetables after harvest in the field to maintain the quality during transportation and storage. Also, the application of water-spraying in vacuum cooling technology can considerably reduce the negative influence caused by vacuum pre-cooling.