Suppression of cold-induced phospholipase Dζ1 mitigated chilling injury in green peppers during low-temperature storage

A comprehensive physiological and -Omic analysis of trypsin-mediated protection of green pepper fruits from chilling injury

Storing `Maor' green bell peppers (Capsicum annuum L.) for 3 weeks at 2C resulted in the development of chilling injury (CI) evidenced as surface pitting. Fruit held at 8C did not develop any CI symptoms, but, after 3 weeks of storage, the fruit began to change color from green to red. PAM fluorometry was used to measure changes in photosynthetic competency in whole green bell peppers. Three photosynthetic characteristics could be measured by this method: quantum yield (Fm/Fe), photochemical quenching (Qp), and nonphotochemical quenching (Qnp). Fm/Fo decreased 90% during the first week of storage at 2C and remained low thereafter, while Qnp decreased after 2 weeks at 2C, just before the peppers began to develop CL Qp was similar at both storage temperatures. Potassium leakage as a CI measurement also increased in excised pepper discs after 2 weeks at 2C. The results indicate that PAM fluorometry can measure CI nondestructively before tissue damage is visible in green peppers.

Diphenylamine reduces chilling injury of green bell pepper fruit

Present study was aimed at understanding the effect of pretreatments and modified atmosphere packaging on the quality of fresh-cut green bell pepper (Capsicum annuum L.) during low temperature storage. Dip treatment of freshly cut green bell pepper pieces in 2% calcium propionate followed by surface drying and subsequent packing in cryovac PD961 film which maintained an equilibrium modified atmosphere of 13-14% O2 and 7% CO2 helped to extend the marketability till 9days storage at 8°C. The microbiological quality was at the best level up to 6days of storage, as evidenced by a surge in aerobic plate count, pectinolysers and pseudomonads on subsequent days. Head space volatile analysis of the produce at regular intervals showed a reduction in monoterpenoids and simultaneous increase of aldehydes and ketones, sesquiterpenoids, esters, furans and pyrazines during storage. Principal component analysis of the head space volatiles identified, cis - ocimene, 1,3,8-paramenthatriene, trans 3- caren 2-ol, bergamotene, 2-hexenal, ethyl 1- decanol, (E)-3- hexenol and heptane thiol as the markers of freshness in minimally processed green bell pepper.

Hydroxypropyl cellulose reduces chilling injury in green bell pepper (Capsisum annuum L.) by regulating the activity and gene expression of enzymes involved in antioxidant and membrane lipid metabolism

Calcium ion improves cold resistance of green peppers (Capsicum annuum L.) by regulating the activity of protective enzymes and membrane lipid composition

Low temperatures are often used to preserve fruits and vegetables. However, low-temperature storage also causes problems, such as chilling injury, nitrite accumulation, and browning aggravation in plants. This study investigated the effects of brassinolide (BR,1.0 mg L−1) solution soaking, storage temperatures (−2 ± 0.5 °C, 4 ± 0.5 °C, and 20 ± 1 °C), and their combinations on nitrite content, color change, and quality of stored Toona sinensis bud. The results showed that low temperature (LT, 4 ± 0.5 °C) and near freezing-point temperature (NFPT, −2 ± 0.5 °C) storage effectively inhibited the decay of T. sinensis bud compared to room temperature (20 ± 1 °C, the control). The combined treatments of BR with LT or NFPT reduced nitrite content and maintained the color and the contents of vitamin C, carotenoids, saponins, β-sitosterol, polyphenol, anthocyanin, flavonoids, and alkaloids in T. sinensis bud. BR soaking delayed the occurrence of chilling injury during NFPT storage. Meanwhile, BR soaking enhanced the DPPH radical scavenging activity, ABTS activity, and FRAP content by increasing SOD and POD activity and the contents of proline, soluble, and glutathione, thus decreasing MDA and hydrogen peroxide content and the rate of superoxide radical production in T. sinensis bud during NFPT storage. This study provides a valuable strategy for postharvest T. sinensis bud in LT and NFPT storage. BR soaking extended the shelf life during LT storage and maintained a better appearance and nutritional quality during NFPT storage.

This experiment was conducted on the variety 'Marmandi' turning tomato fruits to investigate the effect of intermittent warming temperatures during extended low chilling temperature storage (21 days) on the subsequent ripening quality of tomato fruits. The quality was measured by assessing the quantitative amount of total phenolic compounds, chlorogenic acid, and ascorbic acid, as well as the development of fruit color and the evaluation of chilling injury (CI) symptoms. The results indicated that the amounts of total phenolic compounds and chlorogenic acid increased significantly during continuous low-temperature storage and after subsequent transfer to room temperature, with this increase being associated with significant loss of ascorbic acid. More frequent periods of intermittent warming (IW) during low-temperature storage were very effective in significantly decreasing the rate of accumulation of phenolic compounds, chlorogenic acid, and ascorbic acid losses. A significant reciprocal relationship between the amounts of chlorogenic acid and ascorbic acid was observed. Additionally, the results showed that as IW time increased, its effectiveness in retarding CI significantly improved.

H2S treatment alleviates postharvest chilling injury in green pepper by regulating antioxidant capacity, osmotic regulation and lipid metabolism to maintain cell membrane integrity.

Low temperature storage is widely used for storage and transportation of fruits and vegetables after harvest. As a cold-sensitive fruit vegetable, post-harvest solanaceous vegetables and fruits are susceptible to chilling injury during low temperature storage, which reduces its sensory quality and edible quality and shortens its storage period, thus leading to huge economic losses. Therefore, it is an essential to clarify the occurrence mechanism of chilling injury caused by low temperature storage in solanaceous vegetables and fruits, and to propose corresponding prevention and control measures for chilling injury. In recent years, a series of progress has been made in the research on chilling injury prevention and control and low temperature stress tolerance of solanaceous vegetables and fruits. This paper describes the chilling injury symptoms of postharvest solanaceous vegetables and fruits, clarifies the physiological and biochemical mechanisms in the chilling injury process, the molecular mechanisms, and prevention and control measures, and summarizes the latest research advancements on chilling injury and chilling tolerance regulation of solanaceous vegetables and fruits, which can provide valuable references for low temperature storage and chilling injury prevention and control measures of solanaceous vegetables and fruits.

Hydrogen peroxide receptors regulate chilling injury of banana fruit during low-temperature storage

Introduction. Longkong (Aglaia dookkoo Griff.) fruit is a non-climacteric tropical fruit and grows widely in the South-East Asia. It has a unique taste and nutritional properties that make it more valuable to export. However, longkong exhibits a shorter shelf life at ambient (25 °C for 3−5 days) and low temperature (13 °C for 10 days) storage. Therefore, there is an urgent need to extend its shelf life and marketability by using an inexpensive and proficient technique. Materials and methods. Methyl jasmonate (MeJA) treatments with different concentrations (10, 20 and 30 μ Mol L-1 ) were used to control physiological and biochemical quality changes of longkong fruit stored at 13 °C and 85% relative humidity. Fruit with no MeJA treatment served as control. The physiological and biochemical quality analyses were carried out at every four days of the interval. Results and discussion. Longkong pericarp chilling injury (CI) index and ion leakage severely increased in the control fruits as compared with MeJA treated fruit. The increased of pericarp phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD) activities were well controlled by MeJA treatments. Fruit polygalacturonase (PG), pectin methyl esterase (PME) and lipoxygenase (LOX) activities were significantly controlled in MeJA treated fruit. Fruit superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities found higher level in the MeJA treated fruit. Conclusion. The different concentrations of MeJA treatment effectively reduced the severity of physiological and biochemical quality changes in longkong fruit under prolonged low temperature storage.

SUMMARYResearch backgroundLow temperature storage causes chilling injury in plum (Prunus domestica L.) fruits. Consequently, any treatments with beneficial effects against these symptoms would achieve attention. For this purpose, phenylalanine treatments were applied on ‘Stanley’ plum fruits. The main purpose of the present study is to investigate the influence of the exogenous application of phenylalanine on fruit quality, chilling tolerance, and antioxidant capacity of ‘Stanley’ plums during cold storage.Experimental approachPhenylalanine at different concentrations was applied on ‘Stanley’ plums. Following phenylalanine application, plums were cold stored. Chilling injury, antioxidant capacity, electrolyte leakage, malondialdehyde, proline and internal contents of anthocyanin, flavonoids, phenols, ascorbic acid and some antioxidant enzymes were assessed.Results and conclusionsPhenylalanine treatment significantly alleviated chilling injury in plum fruits by enhancing antioxidant capacity and increasing the activity of phenylalanine ammonia lyase enzyme (PAL). Phenylalanine-treated fruits had higher mass fractions of ascorbic acid, anthocyanins, flavonoids and phenols, as well as a higher total antioxidant activity than the control fruits during low temperature storage. Phenylalanine at 7.5 mM was the most effective treatment in enhancing the activity of PAL, the accumulation of phenolic compounds and in reducing the severity of chilling injury. Treatments delayed mass loss and maintained fruit firmness. In addition, the application of 7.5 mM phenylalanine improved the activities of antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase), decreased the accumulation of hydrogen peroxide, and increased the endogenous content of proline. Moreover, phenylalanine maintained membrane integrity, manifested by a reduced electrolyte leakage and malondialdehyde accumulation.Novelty and scientific contributionIn the current study, chilling injury had a positive correlation with the activities of PAL and antioxidant enzymes. However, negative correlations were observed between the chilling injury and ascorbic acid mass fraction, and antioxidant capacity. Considering the results, phenylalanine treatment could be an encouraging approach to alleviate the severity of chilling injury and thus preserve nutritional quality of plums during low temperature storage.

Low-temperature storage is extensively used to optimize the postharvest life of various fresh fruits. However, red pitahaya (Hylocereus polyrhizus) fruits are sensitive to chilling injury (CI), which leads to the limitation of low-temperature storage. In this study, red pitahaya fruits were stored at 2, 4, 6, 8, and 10°C, respectively, for 27 days to determine the appropriate storage temperature. During the storage of red pitahaya fruits, storage at 8°C was more effective in suppressing decay and maintaining quality than other low temperatures. Low-temperature (2, 4, and 6°C) storage decreased weight loss (WL) and maintained higher content of titratable acidity (TA), soluble sugars (SS), and total phenolics (TP) but different degrees of CI were detected. No CI was observed at 8°C and 10°C. Red pitahay as stored at 8 and 10°C were associated with better color evaluation, lower electrolyte leakage (EL), respiration rate, and lipoxygenase (LOX) activity, and higher fruit firmness, superoxide dismutase (SOD) activity, and catalase (CAT) activity. However, higher storage temperature (10°C) resulted in higher metabolic activity leading to lower quality and antioxidant capacities compared with 8°C. Therefore, our results demonstrated that red pitahaya stored at 8°C exhibited a protective effect on fruit quality and resisted CI development during storage.

Phospholipids constitute the main component of biomembranes. During low-temperature storage and transportation of harvested bell peppers (Capsicum annuum), chilling injury participates in their decay. A primary cause of this chilling injury is phospholipid degradation. In this study, three genes encoding phospholipase D (PLD) were identified from bell peppers and their activities were examined under cold stress. Low temperature (4 °C) induced strong accumulation of the CaPLDα4 transcript, suggesting that it is associated with the phenomenon of phospholipid degradation and destruction of cell membranes. Low temperature also significantly induced increased amounts of NAM-ATAF1/2-CUC2 (NAC) domain transcription factors. CaNAC1 was found to interact with the promoter of CaPLD4 in a yeast one-hybrid screen. Electrophoretic mobility shift and ß-glucuronidase reporter assays demonstrated that CaNAC1 binds to the CTGCAG motif in the CaPLDα4 promoter, thereby activating its transcription and controlling phospholipid degradation. The ubiquitination sites of the CaNAC1 protein were characterized by liquid chromatography-tandem mass spectrometry. We conclude that CaNAC1 is a transcriptional activator of CaPLDα4 and suggested that it participates in the degradation of membrane lipids in bell peppers when they are stored at low temperature.