Abscisic acid alleviates chilling injury in cold-stored peach fruit by regulating ethylene and hydrogen peroxide metabolism

Peach (Prunus persica (L.) Batsch) is susceptible to chilling injury under improper low-temperature storage (2°C-5°C). Previous research has shown that abscisic acid (ABA) alleviates chilling injury in fruits and vegetables, but the potential mechanism is still unclear. To explore its effectiveness and potential mechanism in alleviating chilling injury during cold storage, exogenous ABA was applied to peach fruit by immersion in 100 μmol L^-1 solutions for 10 min. In our experiment, ABA alleviated chilling injury by reducing hydrogen peroxide (H₂O₂) content and ethylene production. In addition, ABA inhibited the expression of the ethylene synthesis-related genes PpACO1 and PpEIN2. At the same time, ABA activated the antioxidant enzymatic pathway and the ascorbate-glutathione (AsA-GSH) cycle, the transcript abundance encoding genes related to antioxidant enzyme activities also changed correspondingly. The results suggested that ABA alleviated chilling injury by scavenging excessive H₂O₂ by promoting antioxidant enzymes and the AsA-GSH pathway.

Ethylene Control Technologies in Extending Postharvest Shelf Life of Climacteric Fruit

Fresh fruit is important for a healthy diet. However, because of their seasonal production, regional specific cultivation, and perishable nature, it is essential to develop preservation technologies to extend the postharvest shelf life of fresh fruits. Climacteric fruit adopt spoilage because of ethylene, a key hormone associated with the ripening process. Therefore, controlling ethylene activity by following safe and effective approaches is a key to extend the postharvest shelf life of fruit. In this review, ethylene control technologies will be discussed aiming for the need of developing more innovative and effective approaches. The biosynthesis pathway will be given first. Then, the technologies determining the postharvest shelf life of climacteric fruit will be described with special attention to the latest and significant published works in this field. Special attention is given to 1-methylcyclopropene (1-MCP), which is effective in fruit preservation technologies. Finally, the encapsulation technology to improve the stability of 1-MCP will be proposed, using a potential encapsulation agent of 1-MCP, calixarene.

Preliminary report on a catalyst derived from induced cells of Rhodococcus rhodochrous strain DAP 96253 that delays the ripening of selected climacteric fruit: bananas, avocados, and peaches

Despite the use of refrigeration, improved packaging, adsorbents, and ethylene receptor blockers, on average, nearly 40% of all fruits and vegetables harvested in the US are not consumed. Many plant products, especially fruit, continue to ripen after harvesting, and as they do so, become increasingly susceptible to mechanical injury, resulting in increased rot. Other plant products during transportation and storage are susceptible to chill injury (CI). There is a real need for products that can delay ripening or mitigate the effects of CI, yet still permit full ripeness and quality to be achieved. Preliminary results are discussed where catalyst derived from cells of Rhodococcus rhodochrous DAP 96253, grown under conditions that induced high levels of nitrile hydratase, were able to extend the ripening and thus the shelf-life of selected climacteric fruits (banana, avocado, and peach). A catalyst, when placed in proximity to, but not touching, the test fruit delayed the ripening but did not alter the final ripeness of the fruit tested. Organoleptic evaluations conducted with control peaches and with peaches exposed to, but not in contact with, the catalyst showed that the catalyst-treated peaches achieved full, natural levels of ripeness with respect to aroma, flavor, sweetness, and juice content. Furthermore, the results of delayed ripening were achieved at ambient temperatures (without the need for refrigeration).

Influence of Harvest Dates on Quality, Storage Capacity and Sensory Attributes of European Plum cv. Green Gage

The aim of this work was to determine storage capacity and changes in quality and consumer acceptance in plum harvested at different dates as well as to determine which instrumental parameters show good correlation with consumer acceptance and sensory properties. Both harvest date and storage time played a significant role in quality and sensory characteristics. Incidence of internal breakdown (IB) was significantly higher in fruit harvested last and increased significantly until the end of storage. Market life of ‘Green Gage’ plum varies from 20 days in fruit harvested on the last harvest date to 40 days in fruit harvested on earlier dates. When storage is needed, firmness, the best harvest index, should be higher than 42 N in order to extend market life and prevent IB damages in ‘Green Gage’ plums. However, fruit from early harvest dates has a lower consumer acceptance than fruit from late harvest dates (low TSS:TA). Thus, a minimum quality threshold based on TSS:TA (18.9) has been established over which consumer liking for European plums cv. Green Gage improves significantly. High linear regression between a* and TSS:TA would allow to use the a* color parameter as a nondestructive measurement to estimate consumer acceptance.