1-MCP Treatment Research Articles

Effect of Storage Conditions and Cooking Methods on Chlorophyll, Glucosinolate, and Sulforaphane Content in Broccoli Florets

The effects of storage conditions and cooking methods on chlorophyll, glucosinolate (GSL), and sulforaphane content in broccoli florets were investigated in this study. For the storage experiment, fresh broccoli florets were stored for 2, 4, and 6 days at 10, 4, and 0 °C with or without 1-methylcyclopropene (1-MCP) treatment. For the cooking experiment, fresh broccoli florets were cooked for 1, 3, 5, 7, and 9 min under three cooking methods, namely, steaming, microwaving, and boiling. Results showed that the contents of chlorophyll, aliphatic GSL, indole GSL, and sulforaphane in broccoli florets of two cultivars decreased with prolonged storage time. The retained contents of chlorophyll, GSLs, and sulforaphane under 0 °C storage condition were significantly higher than those under 10 °C storage condition after 6 days of storage. The sulforaphane content was increased by 1-MCP treatment but differed among varieties. The cooking experiment showed that aliphatic GSL content decreased with increased cooking time under three cooking methods, and indole GSL and sulforaphane contents had a fluctuating trend with increasing cooking time after steaming and microwaving. Sulforaphane content increased by 17.15–50.16% relative to that in fresh broccoli florets and was considerably affected by cooking time. The highest level of sulforaphane content was retained for 7 min during steaming or 5 min during microwaving. Therefore, the combination of 1-MCP treatment and 0 °C storage condition had the best performance in preserving chlorophyll, GSLs, and sulforaphane. Moreover, steaming for 7 min or microwaving for 5 min is a more effective method for preserving the quality and increasing the sulforaphane content of broccoli florets than boiling.

Regulations and mechanisms of 1-methylcyclopropene treatment on browning and quality of fresh-cut lotus (Nelumbo nucifera Gaertn.) root slices

The quality of fresh-cut lotus root slices is greatly affected by enzymatic browning. In this study, we investigated the effects of 1-methylcyclopropene treatment on browning and quality deterioration of lotus root slices. When fresh-cut lotus root slices were immersed in 0.1 mg L−1 1-MCP for 1 h and stored at 10 ℃ for twelve days, microbial growth, respiration, total phenolic content, phenylalanine ammonia lyase activity, polyphenol oxidase activity, and soluble quinone levels in fresh-cut lotus root slices were suppressed. Furthermore, 1-MCP treatment improved the antioxidant capacities, peroxidase activities, superoxide dismutase activities, catalase activities, and DPPH free radical scavenging rates in fresh-cut lotus root slices. In addition, 1-MCP treatment inhibited the production of reactive oxide species, which delayed quality deterioration of fresh-cut lotus root slices. Based on transcriptomics and real-time quantitative PCR results, gene expression levels of NnmetK2, NnACO, NnETR2, NnEIN3, and NnERF1 were up-regulated while expression levels of NnEBF1 were down-regulated. These findings indicate that 1-MCP inhibits ethylene biosynthesis and signal transduction, which suppresses a series of ethylene-induced physiological and biochemical reactions. Based on our findings, we propose a new strategy for inhibiting enzymatic browning in fresh-cut lotus root slices.

Effects of 1-methylcyclopropene treatment on phenolic metabolism in postharvest Gynura bicolor DC

We examined the effects of 10 μ L−1 1-methylcyclopropene (1-MCP) treatment on phenolic metabolism in postharvest Gynura bicolor DC stored at 20 ± 2 °C. The results indicated that 1-MCP treatment stimulated the biosynthesis of flavonoids and anthocyanins but inhibited that of lignin by regulating gene expression and enzyme activity. Specifically, 1-MCP treatment increased the contents of cinnamic acid, kaempferol, rutin, and chlorogenic acid by upregulating the expression of GbPAL, GbCHS, GbDFR, GbANS and GbUFGT, and decreased the ferulic acid content by downregulating the expression of GbC4H, GbCOMT, GbF5H and GbCCoAOMT. A correlation heatmap suggested close relations between individual phenolics and gene expression. The resulting accumulation of phenolics enhanced 2,2-diphenyl-1-picrylhydrazyl hydrate radical (DPPH·) and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS·+) scavenging ability and ferric ion-reducing antioxidant power (FRAP). Furthermore, 1-MCP treatment decreased electrolyte leakage and inhibited the activity of peroxidase and polyphenol oxidase, alleviating the risks of phenolics degradation and the increase in superoxide anion (O2·−) and H2O2 levels. In summary, 1-MCP treatment increased the contents of total phenolics, flavonoids, and anthocyanins by stimulating gene expression, and retarded the risk of phenolic degradation, thus delaying senescence of G. bicolor leaves.

Fruit Quality Attributes of ‘Arisoo’ and ‘Picnic’ Apples as Influenced by 1-Methylcyclopropene Concentration and Its Application Frequency during Cold Storage

The efficacy of 1-methylcyclopropene (1-MCP) in maintenance of apple fruit quality can differ depending on apple cultivar, ethylene content at harvest, 1-MCP concentration, the interval between harvest and 1-MCP application, and the number of applications. In this study, we investigated whether the 1-MCP concentration and its application frequency differently affected fruit quality attributes of the two new apple cultivars ‘Arisoo’ and ‘Picnic’. The fruits were treated with 1-MCP (as single or double treatments) at the rate of 0 μL L−1 (control), 0.5 μL L−1, 1 μL L−1, 0.5 + 0.5 μL L−1, and 1 + 1 μL L−1 for 18 h, and they were stored at 0 °C up to six months. Comparatively, the fruit qualities of 1-MCP treated fruits were higher than that of the control during cold storage, with a higher suppression of internal ethylene content and a slower reduction of titratable acidity in 1-MCP treatments than the controls throughout the cold storage in both cultivars, regardless of the concentration and number of applications. Reduction of fruit firmness and soluble solid contents were maintained by single application of 0.5 μL L−1 1-MCP in ‘Arisoo’ apple, while double application of 0.5 + 0.5 μL L−1 was needed in ‘Picnic’ cultivar. The effective concentration for weight-loss reduction was found to be the single application of 1 μL L−1 1-MCP in both ‘Arisoo’ and ‘Picnic’. Conclusively, 1-MCP as single treatment at the rate of 0.5 μL L−1 could be sufficient in inhibiting ethylene action and maintaining fruit quality losses during cold storage, particularly in ‘Arisoo’. However, double application of 1-MCP might be necessary for some quality attributes in ‘Picnic’ apple.

Effects of 1-methylcyclopropene and gaseous ozone on Listeria innocua survival and fruit quality of Granny Smith apples during long-term commercial cold storage

This study evaluated the impact of 1-methylcyclopropene (1-MCP), an ethylene synthesis inhibitor, followed by long-term commercial cold storage with low-dose gaseous ozone on the microbiological safety and quality of fresh apples. Granny Smith apples were inoculated with or without Listeria innocua, treated with or without 1.0 mg/L 1-MCP for 24 h, then subjected to commercial cold storage conditions including refrigerated air (RA, 0.6 °C, control), controlled atmosphere (CA, 2% O2, 1% CO2, 0.6 °C), and CA with 51–87 μg/L ozone gas for up to 36 weeks. RA storage reduced L. innocua on apples by up to 3.6 log10 CFU/apple. CA had no advantage over RA in controlling Listeria. Continuous ozone gas application resulted in an additional ∼2.0 log10 CFU/apple reduction of L. innocua (total reduction up to 5.7 log10 CFU/apple) and suppressed native bacteria and fungi. Treatment with 1-MCP had a minor impact on survival of L. innocua or background microbiota on apples, while it significantly delayed fruit ripening and reduced the incidence of superficial scald and internal browning. In summary, 1-MCP treatment followed by CA storage with low-dose continuous ozone gas can effectively control Listeria on fresh apples and delay fruit ripening.

Physicochemical changes in fresh-cut peaches with the combined treatment of UV-B irradiation and 1-MCP

Fresh-cut peaches are prone to quality deterioration, including browning, which is detrimental to their shelf life and marketability. Physiochemical changes in the fruit treated with the combination of a hormetic dose of UV-B irradiation (1.46 kJ m−2) and 1 μl L−1 1-MCP fumigation were assessed. The combined treatment effectively maintained the fruit quality as indicated by the inhibited weight loss and browning, which was associated with the enhancement of total phenolic content by UV-B, and restraint activities of polyphenol oxidase and peroxidase by 1-MCP. Meanwhile, a stable membrane was suggested based on the facts of the reduced membrane peroxidation and improved unsaturated fatty acid proportion. Moreover, the retarded energy deficit was coupled with moderated respiratory metabolism. In summary, the combination of UV-B and 1-MCP treatments compromised phenolic metabolism, enhanced membrane stability, and moderated respiratory metabolism, and hence can be used to extend the shelf life of fresh-cut peaches.

Effects of 1-MCP on the Physiological Attributes, Volatile Components and Ester-Biosynthesis-Related Gene Expression during Storage of ‘Jinyan’ Kiwifruit

The effects of 1.0 μL/L 1-methylcyclopropene (1-MCP) treatment on aroma quality and ester-biosynthesis-related gene expression of ‘Jinyan’ kiwifruit during room storage were examined, aiming to provide a theoretical basis and technical reference for the postharvest storage of kiwifruit. The results demonstrate that 1-MCP treatment conspicuously inhibited respiration rate, delayed a decrease in fruit firmness and increased soluble solid content (SSC) in ‘Jinyan’ kiwifruit. Compared to the control, the relative content of aroma components markedly changed in 1-MCP treatment kiwifruit during fruit ripening. The characteristic aroma of ‘Jinyan’ kiwifruit included ethyl butanoate, methyl butanoate, E-2-hexanal and hexenal, and 1-MCP treatment significantly reduced the ester content in kiwifruit. During the entire shelf life, the expression levels of AcLOX1, AcLOX5, AcLOX6, AcHPL and AcAAT were significantly inhibited in 1-MCP-treated fruit. However, the transcript level of AcADH was not suppressed by 1-MCP. The lower content of ester volatiles maybe ascribed to the suppression of AcLOXs, AcHPL and AcAAT.

Investigating the Effect of Fruit Size on Ripening Recovery of Banana Treated with 1-Methylcyclopropene

Postharvest application of 1-methylcycloprepene (1-MCP) on banana fruit to extend shelf-life and maintain quality is inconsistent as treated fruit do not ripen uniformly. Banana response to 1-MCP treatment can be variable due to within-bunch variation in fruit size, composition, and maturity. Therefore, the present study investigated whether fruit size variation explains variability in ripening recovery. To investigate this relationship, large, medium, and small fruit were treated with 0 nL L−1 1-MCP (control), 400 nL L−1 1-MCP and 50 µL L−1 ethephon + 400 nL L−1 1-MCP. Fruit were then ripened using 800 µL L−1 ethephon and stored at 23 °C for 30 d. Irrespective of fruit size, treating banana with 1-MCP and ethephon + 1-MCP prolonged shelf-life by 30 d compared to control, which were fully ripe at 15 d for medium and large fruit, and 20 d for small fruit. 1-MCP significantly delayed yellow colour development (colour stage 4), chlorophyll degradation (97.4 µg/g), and sucrose (2.57 mg/g) and glucose (0.86 mg/g) accumulation in small compared to medium and large fruit. However, firmness (56.13 N) and starch (0.68 mg/g) were significantly lower in 1-MCP-treated small-sized fruit compared to medium and large fruit. Moisture loss was also significantly higher (19.49%) in 1-MCP-treated small fruit compared to medium (14.89%) and large (18.11%). Combined ethephon and 1-MCP allowed for an increase in ripening in small, medium, and large fruit. Overall, medium and large fruit treated with 1-MCP and ethephon + 1-MCP recovered their ripening capacity better compared to small fruit. The results demonstrate that 1-MCP efficacy is influenced by fruit size, whereas ethephon + 1-MCP treatment was consistent across small, medium, and large fruit. The effect of fruit size on 1-MCP efficacy might explain the inconsistency of the treatment in the banana fruit. Therefore, it is important to apply 1-MCP on fruit of approximately the same size to achieve the full benefit of the treatment. Moreover, fruit treated with 1-MCP + ethephon recovered their ripening capacity, irrespective of size, suggesting that it is a beneficial treatment.

Effect of 1-Methylcyclopropene on the Storage Quality of Lonicera caerulea L.

Objective: In order to explore the effect of 1-Methylcyclopropene (1-MCP) on the storage quality of Lonicera caerulea L., with a view to providing theoretical and practical basis for Lonicera caerulea L. storage and preservation technology. Methods: The experiment using the Lonicera caerulea L. variety “Lanjingling” as the test material, after harvesting, it was treated with a concentration of 1 µL/L 1-MCP for 24 h, and the effect of 1-MCP treatment on the storage quality, physiological changes and anti-oxidant effects of the fruits during storage at ice temperature (−0.5±0.3) ℃ was studied. Results: Compared with the control, 1-MCP treatment delayed the decrease of good fruit rate, frost coverage index and flavor index during storage. The hardness was 1.39 kg/cm2 at 60 days of storage, which was significantly higher than the hardness of CK group (0.95 kg/cm2) during the same period and maintained the organoleptic qualities and inherent texture of the fruit. In early storage, 1-MCP treatment such as ascorbic acid, anthocyanins, flavones and total phenol content was maintained at a high level, while suppressing respiration and MDA content of the fruits, the biologically active material was suppressed and the decrease of delaying the senescence of fruits. In terms of antioxidant properties, 1-MCP could effectively slow down the decrease of T-GSH, GSH, and GSSG content, while maintaining high GR and SOD activities in the early stage of storage, thereby achieving the ability to maintain the antioxidant capacity of the fruits. Conclude: 1-MCP can effectively maintain the quality of Lonicera caerulea L. during the postharvest storage period.

The regulation of 1-methylcyclopropene treatment on the subfamily genes expression of ethylene response factors in peaches during storage.

Ethylene response factors (ERFs) perform diverse functions in fruit development, ripening and senescence. However, the effects of postharvest treatments on ERF genes have not been widely investigated due to the lack of peach ERF genomic information. The aim of this study was to investigate the ERF genes' expression of freshly harvested peach during storage after 1-methylcyclopropene (1-MCP) treatment. 10 μL L-1 1-MCP was used to fumigate peaches. Treated peaches and control peaches were stored at 20°C for 9 days. Fruit firmness, ethylene production and the transcript abundance of ERFs were evaluated during storage. 127 AP2/ERF genes were identified genome using RNA-sequencing (RNA-seq). Expression profiles of 39 ERF genes were considered at day 0, 3, 5 and 7. Results showed that 1-MCP inhibited some ERF genes' expression (e.g., Prupe.5G117800), some genes were generally up-regulated responding to 1-MCP (e.g., Prupe.6G039700), while the other ERF genes displayed no significant difference between the two groups (e.g., Prupe.1G130300). These data revealed that peach ERF genes perform diverse functions during fruit growth, ripening and senescence. The different responses of ERF genes to postharvest 1-MCP treatment may be useful to understand the roles of ethylene and ERF genes in controlling technological aspects of postharvest peach conservation.

Effects of 1-Methylcyclopropene Treatment on Fruit Quality during Cold Storage in Apple Cultivars Grown in Korea

The effect of 1-methylcyclopropene (1-MCP) treatment on improving the storability of four apple cultivars (‘Hwangok’, ‘Picnic’, ‘Gamhong’, and ‘Fuji’) was investigated by analyzing the physiological and biochemical factors associated with their postharvest quality attributes. The flesh firmness, titratable acidity, and soluble solids content of the cultivars were higher in treated fruits than untreated fruits, while the opposite results were observed for ethylene production. In the treated fruits, the traits affected by 1-MCP varied depending on the cultivars used. Higher firmness and lower ethylene production were observed in the ‘Hwangok’ and ‘Picnic’ than ‘Gamhong’ and ‘Fuji’ cultivars. However, 1-MCP only affected weight loss in the ‘Gamhong’ cultivar, while the sugar content was affected in all of the cultivars except ‘Hwangok’. When analyzing cell wall hydrolase activities, 1-MCP differently affected the activities (β-galactosidase, α-galactosidase, β-glucosidase, α-mannosidase, β-xylosidase, and β-arabinosidase), with greater effects in the ‘Fuji’ and ‘Picnic’ cultivars and moderate effects in the ‘Gamhong’ and ‘Hwangok’ cultivars. In this study, the suppression of ethylene production by 1-MCP was positively associated with a transcriptional decrease in the ethylene biosynthesis genes MdACS1 and MdACO1. Overall, this study suggests that 1-MCP distinctly enhanced the storability of all apple cultivars, with a greater effect on ‘Hwangok’.

Physiological disorder development of ‘Honeycrisp’ apples after pre- and post-harvest 1-methycyclopropene (1-MCP) treatments

Susceptibility of apple fruit to physiological storage disorders is affected by both pre- and postharvest factors that influence their ethylene production. In this study, the inhibitor of ethylene perception, 1-methycyclopropene (1-MCP), applied before and after harvest, has been used to investigate the interactions between ethylene and development of physiological disorders in ‘Honeycrisp’ apples during storage. Preharvest 1-MCP (Harvista™) was applied to trees, either 2 weeks (early), 1 week (late), at 1 and 2 weeks (repeated), or at double rate 1 week, before first commercial harvest. Fruit were then untreated or treated with postharvest 1-MCP (SmartFresh®) and stored at 0.5 °C, or conditioned at 10 °C for 7 d and then stored at 3 °C (C + 3 °C), for 20 weeks. Fruit quality and physiological disorders were assessed after 4 d at 20 °C. Fruit from all preharvest 1-MCP treatments had lower internal ethylene concentrations (IECs) and were greener as indicated by higher IAD values compared with untreated controls, while effects on starch pattern indices (SPI) were inconsistent. After storage, preharvest 1-MCP -treated fruit were firmer than untreated fruit, but effects of the different application timings were inconsistent. Effects of postharvest 1-MCP on IEC and IAD values were greater at 0.5 °C than at C + 3 °C. High incidences of core browning and vascular browning developed during storage, especially in the preharvest 1-MCP-treated fruit. Soft scald was reduced by preharvest 1-MCP treatments compared with control. In the C + 3 °C storage treatment, preharvest 1-MCP-treated fruit had a higher bitter pit incidence than in control fruit, but less skin wrinkling and senescent breakdown. Postharvest 1-MCP treatment of preharvest 1-MCP fruit slightly decreased bitter pit incidence while greatly increasing that of core browning and leather blotch, and sometimes flesh browning and carbon dioxide injury. This study shows that pre- and postharvest inhibition of ethylene perception by 1-MCP can have marked effects on storage disorders that are affected by fruit maturity and storage temperatures.

Impact of postharvest hot water, 1-MCP and CaCl2 treatments on antioxidant enzymes and related genes during cold storage in sweet cherry (Prunus avium L.)

Impact of postharvest hot water, 1-MCP and CaCl2 treatments on antioxidant enzymes and related genes during cold storage in sweet cherry (Prunus avium L.)

Dynamic Microbiome Changes Reveal the Effect of 1-Methylcyclopropene Treatment on Reducing Post-harvest Fruit Decay in "Doyenne du Comice" Pear.

Pathogen-induced decay is one of the most common causes of fruit loss, resulting in substantial economic loss and posing a health risk to humans. As an ethylene action inhibitor, 1-methylcyclopropene (1-MCP) can significantly reduce fruit decay, but its effect on fruit pathogens remains unclear. Herein, the change in microbial community structure was analyzed using the high-throughput sequencing technology, and characteristics related to fruit quality were determined after 1-MCP (1.0 M l L–1) treatment in “Doyenne du Comiceis” pear fruit during storage at ambient temperature. Overall, 1-MCP was highly effective in reducing disease incidence and induced multiple changes of the fungal and bacterial microbiota. At day 15, the microbial diversity of fungi or bacteria was reduced significantly in the control fruit (non-treated with 1-MCP), which had the most severe decay incidence. For fungi, in addition to Alternaria being the most abundant in both 1-MCP treatment (59.89%) and control (40.18%), the abundances of Botryosphaeria (16.75%), Penicillium (8.81%), and Fusarium (6.47%) increased significantly with the extension of storage time. They became the primary pathogens to cause fruit decay in control, but they were markedly decreased in 1-MCP treatment, resulting in reduced disease incidence. For bacteria, the abundance of Gluconobacter (50.89%) increased dramatically at day 15 in the control fruit, showing that it also played a crucial role in fruit decay. In addition, Botryosphaeria, Fusarium fungi, and Massilia, Kineococcus bacteria were identified as biomarkers to distinguish 1-MCP treatment and control using Random Forest analysis. The redundancy analysis (RDA) result showed that the amount of Botryosphaeria, Penicillium, and Fusarium were positively correlated with disease incidence and respiration rate of pear fruits while negatively correlated with fruit firmness. This investigation is the first comprehensive analysis of the microbiome response to 1-MCP treatment in post-harvest pear fruit, and reveals the relationship between fruit decay and microbial composition in pear fruit.

Melatonin and 1‐methylcyclopropene treatments on delay senescence of apricots during postharvest cold storage by enhancing antioxidant system activity

The effect of melatonin (MT) dipping and 1-methylcyclopropene (1-MCP) fumigation either individually or combined, on reducing delaying fruit senescence in apricot fruit was investigated. The results showed that the individual and combined MT and 1-MCP treatments maintained the quality of apricot fruits after harvest and reduced fruit softening, rot, and weight loss. This was mainly attributed to the high levels of ascorbic acid content, total phenol content, and total flavonoid content, as well as the upregulation of peroxidase, superoxide dismutase, and catalase enzyme activities, which reduced the active oxygen content. Besides, 1-MCP and MT in individual or in combined treatments suppressed the process of membrane lipid peroxidation by inhibiting the malondialdehyde content and lipoxygenase activities, contributing to delaying the senescence of apricot fruits. Among these three treatments, 1-MCP was the best method to delay the postharvest senescence of apricots. Novelty impact statement The individual and combined MT and 1-MCP treatments had positive effect on apricot fruits quality during cold storage. The individual and combined MT and 1-MCP treatments apparently enhanced the activity of enzymatic antioxidants and nonenzymatic antioxidants. Decreased H2O2 generation was observed in the individual and combined MT- and 1-MCP-treated fruits during storage time.

Preharvest 1-methylcyclopropene treatment enhances ‘stress-associated watercore’ dissipation in ‘Jonagold’ apples

The objective of this study was to evaluate the effect of the preharvest application of 1-methylcyclopropene (1-MCP) on postharvest dissipation of stress watercore incidence and severity rating over 30 d at 20 °C. ‘Jonagold’ trees were untreated or sprayed with 1-MCP one week before harvest. Harvest indices and quality factors at 20 °C, were assessed on days 2, 5, 9,15, 20, and 30. Fruit treated with preharvest 1-MCP treatment had lower internal ethylene concentrations and lower starch pattern indices (higher starch concentration) at harvest compared with untreated fruit, but no effects on flesh firmness, soluble solids concentration, titratable acidity, watercore incidence and severity rating, and soluble sugars were detected. At 20 °C, however, preharvest 1-MCP treated fruit had a faster decrease of stress water core incidence and severity than untreated fruit, and delayed development of senescent breakdown and skin shriveling. Sorbitol concentrations were lower in preharvest 1-MCP treated fruit than untreated fruit, but effects on glucose, fructose, sucrose, and starch concentrations were not consistent. More rapid loss of stress-associated water core in preharvest 1-MCP treated fruit was consistent with lower sorbitol concentrations in the cortical tissues.

Preharvest 1-methylcyclopropene treatment effects on fruit quality attributes and targeted metabolites in ‘Wonhwang’ pears stored at room temperature after cold storage

Preharvest 1-methylcyclopropene (1-MCP) spray treatment effects on fruit quality attributes and targeted metabolites were investigated in ‘Wonhwang’ Asian pears during the shelf-life period following cold storage. The preharvest 1-MCP treatment was sprayed 1 week before harvest, and then the pears were stored at 1°C for up to 3 months and then transferred to room-temperature conditions for the shelf-life period. The soluble solids content (SSC) was higher in the preharvest 1-MCP-treated fruit than in untreated fruit at harvest and during the second half of the shelf-life period after cold storage. However, preharvest 1-MCP treatment aggravated the incidence and severity of flesh browning. The contents of asparagine, histidine, valine, and isoleucine were higher in the preharvest 1-MCP-treated fruit than in the untreated fruit during the shelf-life period after cold storage. The results of principal component analysis loading plot indicated that preharvest 1-MCP treatment was strongly associated with leucine, tryptophan, histidine, valine, and isoleucine. In addition, the results of Pearson's correlation coefficient networking indicated that preharvest 1-MCP treatment affected the differential responses of fruit quality attributes and targeted metabolites during the shelf-life period after cold storage. Therefore, the results suggested that preharvest 1-MCP treatment could alter SSC levels and certain targeted metabolites along with internal tissue colour variables in ‘Wonhwang’ pears during the shelf-life period after short-term cold storage.

1-Methylcyclopropene Preserves the Quality of Chive (Allium schoenoprasum L.) by Enhancing Its Antioxidant Capacities and Organosulfur Profile during Storage.

The quality, antioxidant capacities, and organosulfur profile of chives (Allium schoenoprasum L.) treated with 1-methylcyclopropene (1-MCP) during storage were investigated in this study. The 1-MCP treatment (100 μL/L, fumigation 12 h at 20 °C) effectively inhibited tissue respiration and H2O2 production, enhanced the ascorbic acid (ASA) and glutathione (GSH) content, and promoted the activity of antioxidant enzymes (superoxide dismutase SOD, Catalase CAT, and ascorbic peroxidase APX) during the 5-day storage period at 20 °C. The result further showed that the 1-MCP treatment inhibited chlorophyll degradation, alleviated cell membrane damage, and delayed the chive senescence, with the yellowing rate being reduced by 67.8% and 34.5% in the 1-MCP treated chives on days 4 and 5 of storage at 20 °C, respectively. The free amino acid content of the chive was not affected by the 1-MCP treatment at 20 °C. However, the senescence rate of the chive was not reduced by the 1-MCP treatment when stored at 3 °C. The liquid chromatography data further showed that the 1-MCP treatment induced a 15.3% and 13.9% increase in the isoalliin and total S-alk(en)ylcysteine sulfoxides (ACSOs) content of the chive on day 2 at 20 °C, respectively. Furthermore, there was a strong positive correlation between ACSOs content and CAT/APX activity, indicating that ACSOs probably played a key role in enhancing the antioxidant capacities of the chive during storage at 20 °C. Thus the study efficiently demonstrates that 1-methylcyclopropene preserves the quality of chive (Allium schoenoprasum L.) by enhancing its antioxidant capacities and organosulfur profile during storage.

Influence of 1‐methylcyclopropene (1‐MCP) on ripening and ethylene biosynthesis‐related enzyme gene expression in harvested blueberries

The aim of the study was to discuss the effect of 1-methylcyclopropene (1-MCP) with and without ethylene on physiological indexes and ethylene biosynthesis genes expression in blueberries. Results showed that treatment of 1-MCP alone, or with ethylene, improved firmness, soluble solids content, total phenols content, enzyme activities in comparison with control. Treatment with ethylene promoted respiratory action, decay incidence, and browning index comparing with untreated group. In addition, expression levels of AcACS1 and AcACO1 in 1-MCP-treated samples, or associated with ethylene, decreased for different levels during storage that confirmed 1-MCP contributed to the downregulation of ethylene biosynthesis genes expression. Subsequent use of ethylene did not neutralize the effectiveness of 1-MCP on maintaining commercial quality of blueberries. Practical applications The results of this study were helpful to further understand the regulation mechanism of 1-methylcyclopropene (1-MCP) on ethylene biosynthesis genes, which provided theoretical basis for perfecting the fruit ripening theory and reference for the breakthrough of fruit storage and preservation technology. Further studies were needed to explore the action mechanism of 1-MCP treatment on suppressing ethylene biosynthesis genes expression of blueberry fruits by genomics or proteomics techniques.

1-MCP extends the shelf life of ready-to-eat ‘Hayward’ and ‘Qihong’ kiwifruit stored at room temperature

Near eating-stage fruit of ‘Hayward’ and ‘Qihong’ kiwifruit (firmness 20 N) were treated with 0.5 µL L −1 1-Methylcyclopropene (1-MCP) for 12 h at room temperature (23 ±1 °C), and then stored at 23 ± 1 °C for several days. Compared with control fruit, 1-MCP greatly delayed loss of firmness, and extended the room-temperature shelf life of ready-to-eat kiwifruit by an extra 8 d (‘Hayward’) or 10 d (‘Qihong’). The 1-MCP treatment also slowed the declines in titratable acidity and color, but had no significant effects on soluble solids content (p < 0.05). Although in the 1-MCP treated fruit the amounts of total volatiles increased during room-temperature storage, the concentration of total volatiles was lower in the treated fruit compared with the untreated controls. Treatment with 1-MCP inhibited ester production and aldehyde degradation. At edible firmness, kiwifruit treated with 1-MCP showed similar fruit quality compared with the untreated controls, with similar mean values in soluble solids content, titratable acidity and color (p > 0.05). 1-MCP also decreased ethylene production and respiration rate. Moreover, the activities of superoxide (SOD), catalase (CAT) and peroxidase (POD) were increased in the treated fruit compared with the controls. The results indicate treatment with 1-MCP is a potentially effective way of prolonging the room-temperature (23 ± 1 °C) shelf life of ready-to-eat kiwifruit and maintaining their eating quality under commercial conditions.