Reduced Ethylene Production Research Articles

Use of 1-methylcylopropene in cyclodextrin-based nanosponges to control grey mould caused by Botrytis cinerea on Dianthus caryophyllus cut flowers

Botrytis cinerea is one of the pathogens resulting in the heaviest commercial losses in ornamental cut flowers, and the severity of grey mould disease partly depends on the presence of ethylene in the storage environment. The efficacy of a β-cyclodextrin-based nanosponge 1:8 (CD-NS) – 1-methylcyclopropene (1-MCP) complex was evaluated as a novel control agent in protecting carnation ( Dianthus caryophyllus L. ‘Idra di Muraglia’) cut flowers against B. cinerea infection. Two concentrations of this non-volatile 1-MCP formulation (CD-NS complex, 0.25 and 0.5 μL L −1, a.i.) were compared with commercial gaseous 1-MCP (0.25 μL L −1, a.i.), and an inoculated control. A non-inoculated control was also used to assess the natural infection level. Eleven days after inoculation, the development of grey mould on carnation was significantly reduced (59.9% of flower surface) in cut stems treated with the CD-NS complex at low dosage, compared to the high dosage of the CD-NS complex (91.5%), the commercial gaseous 1-MCP formulation (76.2%) and the inoculated control (100.0%). Endogenous ethylene production was associated with symptom development. Results showed a reduced ethylene production in 1-MCP treated flowers (0.25 μL L −1, a.i., both suspended and gaseous formulation). The CD-NS complex could therefore be an effective alternative to conventional chemicals to protect ornamental cut flowers.

Regulation of Ethylene Biosynthesis Under Salt Stress in Red Pepper (Capsicum annuum L.) by 1-Aminocyclopropane-1-Carboxylic Acid (ACC) Deaminase-producing Halotolerant Bacteria

The present study was carried out to understand the mechanism of salt stress amelioration in red pepper plants by inoculation of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase-producing halotolerant bacteria. In general, ethylene production, ACC concentration, ACC synthase (ACS), and ACC oxidase (ACO) enzyme activities increased with increasing levels of salt stress. Treatment with halotolerant bacteria reduced ethylene production by 47–64%, ACC concentration by 47–55% and ACO activity by 18–19% in salt-stressed (150 mmol NaCl) red pepper seedlings compared to uninoculated controls. ACS activity was lower in red pepper seedlings treated with Bacillus aryabhattai RS341 but higher in seedlings treated with Brevibacterium epidermidis RS15 (44%) and Micrococcus yunnanensis RS222 (23%) under salt-stressed conditions as compared to uninoculated controls. A significant increase was recorded in red pepper plant growth under salt stress when treated with ACC deaminase-producing halotolerant bacteria as compared to uninoculated controls. The results of this study collectively suggest that salt stress enhanced ethylene production by increasing enzyme activities of the ethylene biosynthetic pathway. Inoculation with ACC deaminase-producing halotolerant bacteria plays an important role in ethylene metabolism, particularly by reducing the ACC concentration, although a direct effect on reducing ACO activity was also observed. It is suggested that growth promotion in inoculated red pepper plants under inhibitory levels of salt stress is due to ACC deaminase activity present in the halotolerant bacteria.

Ethylene biosynthesis in apricot: Identification of a ripening-related 1-aminocyclopropane-1-carboxylic acid synthase ( ACS) gene

Apricots are climacteric fruits with a high susceptibility to flesh softening and loss of flavor during postharvest storage, and most of the ripening processes are regulated by ethylene, which also has an effect on its own biosynthesis. To understand this process in apricot, inhibition of ethylene biosynthesis and perception was performed for studying key genes involved in the ethylene biosynthetic pathway. Apricots, cv. “Patterson”, were harvested with yellow-green ground color and immediately treated with either the ethylene perception inhibitor 1-methyl cyclopropene (1-MCP) at 10 μL L −1 or the ethylene biosynthesis inhibitor aminoethoxyvinylglycine (AVG) at 1 g L −1. After treatment, quality and physiological attributes such as firmness, color, total soluble solids, acidity, fruit weight, ethylene production and respiration rates were evaluated every 2 d until they ripened at 20 °C. Gene expression analysis was performed by quantitative polymerase chain reaction (qPCR). Both ethylene inhibitors were effective in reducing ethylene production, respiration rate and fruit softening. Three 1-aminocyclopropane-1-carboxylic-acid synthase ( ACS) genes were characterized, but only the expression of ACS2 was highly reduced by ethylene inhibition, suggesting a key role in ethylene synthesis at ripening. Contrarily, ACS1 and ACS3 showed a higher expression under ethylene inhibition suggesting that the corresponding genes are individually regulated in a specific mode as observed in other climacteric fruits. Finally, changes in 1-aminocyclopropane-1-carboxylic-acid oxidase genes did not show a consistent pattern of ethylene modulation.

Timing of postharvest 1-methylcyclopropene treatment affects Bartlett pear quality after storage

DeEll, J. R. and Ehsani-Moghaddam, B. 2011. Timing of postharvest 1-methylcyclopropene treatment affects Bartlett pear quality after storage. Can. J. Plant Sci. 91: 853–858. This study investigated the effects of postharvest 1-methylcyclopropene (1-MCP) treatment timing on the ripening and physiological disorders of Bartlett pears during cold storage and subsequent shelf-life. Pears were held for 1, 3 or 7 d at 3°C after harvest and then treated with 0.3 µL L−1 1-MCP for 24 h at 3°C. Fruit quality attributes were evaluated after 4 mo of cold storage at 0.5°C, plus 1 to 11 d at 22°C. All 1-MCP treatments reduced ethylene production, as well as delayed fruit softening and yellow color development. However, the most substantial benefit of 1-MCP observed was the marked reduction in disorders, especially senescent scald and internal breakdown. The results suggest that 1-MCP treatment 3 d after harvest provided the best balance of reduced disorder development during storage and the ability of Bartlett pears to soften adequately thereafter. Fruit treated with 1-MCP at 1 d after harvest did not soften as much as those treated 3 or 7 d after harvest, while treatment after 7 d provided less control of disorders than treatment after 1 or 3 d.

Timing of postharvest 1-methylcyclopropene treatment affects Bartlett pear quality after storage

DeEll, J. R. and Ehsani-Moghaddam, B. 2011. Timing of postharvest 1-methylcyclopropene treatment affects Bartlett pear quality after storage. Can. J. Plant Sci. 91: 853-858. This study investigated the effects of postharvest 1-methylcyclopropene (1-MCP) treatment timing on the ripening and physiological disorders of Bartlett pears during cold storage and subsequent shelf-life. Pears were held for 1, 3 or 7 d at 3°C after harvest and then treated with 0.3 µL L-1 1-MCP for 24 h at 3°C. Fruit quality attributes were evaluated after 4 mo of cold storage at 0.5°C, plus 1 to 11 d at 22°C. All 1-MCP treatments reduced ethylene production, as well as delayed fruit softening and yellow color development. However, the most substantial benefit of 1-MCP observed was the marked reduction in disorders, especially senescent scald and internal breakdown. The results suggest that 1-MCP treatment 3 d after harvest provided the best balance of reduced disorder development during storage and the ability of Bartlett pears to ...

A novel postharvest UV-C treatment to reduce chilling injury (membrane damage, browning and chlorophyll degradation) in banana peel

To investigate the mode of action of UV-C to alleviate CI in banana. Banana [Musa (AAA group), Cavendish subgroup cv. Cavendish] fruits were treated with UV-C at dosages of 0.03 kJ m −2 prior to storage at 8 or 25 °C. UV-C treatment reduced both the incidence and severity of banana fruits stored under low temperature. UV-C treatment reduced membrane damage indicated by lower activity of lipoxygenase (LOX) and malondialdehyde (MDA) content. In additions, the in vitro polyphenol oxidase (PPO) activity was activated when fruits were stored at CI temperature and UV-C treatment could inhibit the PPO activity. UV-C treatment also delayed yellowing and chlorophyll (Chl) degradation due to the inhibition of chlorophyllase and chl-degrading peroxidase activities. Furthermore, the reduction of ethylene production and respiration rate by UV-C treatment results in extended postharvest shelf life of banana. These finding suggest that the loss of cellular compartments in consequence of membrane degradation, combined with the increase of PPO activity, might contribute to the development of CI in banana peel. UV-C treatment may play an important role in maintained membrane integrity and inhibited PPO activity, reducing the severity of CI symptom and delayed ripening in banana. This novel technique may offer an advance in postharvest handling of bananas and other chilling-sensitive commodities in order to reduce postharvest losses resulting from CI.

1‐MCP suppresses ethylene biosynthesis and delays softening of ‘Hami’ melon during storage at ambient temperature

'Hami' melon is susceptible to softening during postharvest storage at ambient temperature, which enhances postharvest deterioration and limits transportation and storage. To look for a method of softening control, the effect of 1-methylcyclopropene (1-MCP) on regulating postharvest softening of 'Hami' melon fruit was investigated. 1-MCP treatment at 1 µL L(-1) significantly reduced ethylene production and maintained higher levels of fruit firmness. It also markedly inhibited the accumulation of 1-aminocyclopropane-1-carboxylic acid (ACC) and maintained lower activities of ACC synthase and ACC oxidase. In addition, 1-MCP treatment reduced the activities of fruit-softening enzymes such as pectin methyl esterase, polygalacturonase, endo-1,4-β-glucanase and β-galactosidase. 1-MCP was effective in suppressing ethylene production and delaying fruit softening in 'Hami' melon by decreasing the activities of ethylene biosynthesis enzymes and inhibiting fruit-softening enzymes.

Methyl Salicylate Affects the Quality of Hayward Kiwifruits during Storage at Low Temperature

Hayward kiwifruit were treated with methyl salicylate (MeSA) at different concentrations (0, 8, 16, 24, 32 µL.L-1), then stored at 0.5 ºC and 90% RH for 5 months to investigate postharvest quality and ripening behavior. MeSA treatments, especially at 32 µL.L-1 concentrations, were highly effective in reducing ethylene production, fungal decay, APX and CAT activity, weight loss and total soluble solids (TSS) in Hayward kiwifruit, as well as ascorbic acid (AA) and flesh firmness loss compared with that observed in control fruit. Hayward kiwifruit treated with 24 µL.L1 MeSA was lowest pH. Titrable acidity (TA) of the Hayward kiwifruit was not significantly affected by the use of MeSA treatments.

Postharvest quality and chilling injury of plums: benefits of 1-methylcyclopropene

The aim of this work was to evaluate the effect of 1-methylcyclopropene (1-MCP) treatment on the development of chilling injury (CI) symptoms in four plum cultivars and to determine the relationship between the climacteric behaviorof the cultivar and its sensitivity to this disorder. Significant differences in ripening pattern were found between thecultivars after long-term storage. Among the climacteric cultivars, ‘Royal Zee’ plums showed a higher ethylene production rate than ‘Linda Rosa and ‘Friar’ cultivars. On the other hand, the ‘Angeleno’ cultivar behaved as a suppressed climacteric type. The development of translucency symptoms was higher in ‘Royal Zee’ than in ‘Linda Rosa’ and ‘Friar’ plums, and was almost absent in the suppressed climacteric cultivar. 1-MCP treatment significantly reduced ethylene production and the percentage of fruit affected by translucency in all climacteric cultivars. This treatment also delayed the ripening of the fruit during shelf life. In contrast, 1-MCP treatment did not affect the quality of ‘Angeleno’ plums. Collectively these results suggest that the development of chilling injury in plums is related to the climacteric behavior of the cultivar and demonstrated the beneficial effects of 1-MCP maintaining plum quality during storage.

Modified atmosphere packaging of yellow and purple plum cultivars. 1. Effect on organoleptic quality

The effect of modified atmosphere packaging (MAP) on maintaining plum quality was assayed on 4 plum cultivars (2 with yellow and 2 with purple skins) thermo-sealed in baskets with 2 distinct films (M and H) which differed in permeability. Fruit stored with macroperforated film served as a control and lost their quality attributes very rapidly, manifested by accelerated colour changes, softening, decrease in acidity and increase in total soluble solids. The use of MAP retarded these changes, the efficacy being higher in the fruit packed with film M compared with film H as a result of the delay in postharvest ripening, which could be attributed to the effect of MAP on reducing ethylene production rates. With the use of these packages, the storage time with fruit having high quality attributes could be increased 3–4 weeks more as compared with control plums.

1-MCP extends the storage and shelf life of mangosteen ( Garcinia mangostana L.) fruit

Mangosteen ( Garcinia mangostana L.) fruit were harvested when the peel (pericarp) was light greenish yellow with scattered pinkish spots. Fruit were exposed to 1 μL L −1 1-methylcyclopropene (1-MCP) for 6 h at 25 °C and were then stored at 25 °C (control) or 15 °C. The 1-MCP treatment only temporarily delayed softening of the fruit flesh, during storage. Storage life, defined as the time until the pericarp was dark purple, was much longer in fruit stored at 15 °C than in fruit stored at 25 °C. It was also longer in 1-MCP treated fruit (storage life at 15 °C: control 18 d, 1-MCP-treated fruit 27 d). The 1-MCP treatment also increased the length of shelf life, defined as the time until the pericarp turned blackish purple or showed calyx wilting, at 25 °C. 1-MCP treatment reduced ethylene production. It also reduced pericarp levels of 1-aminocyclopropane-1-carboxylic acid (ACC), and the pericarp activities of ACC synthase (ACS) and ACC oxidase (ACO). In the fruit flesh, in contrast, 1-MCP did not affect ACC levels and ACS activity, but the treatment reduced ACO activity. Taken together, both the storage life and the shelf life of the fruit were extended by the 1-MCP treatment. A decrease in ACO activity largely accounted for the effects of the 1-MCP on ethylene production in the pericarp.

ACC oxidase 발현 억제 식물체에서 폴리아민 생합성 증가에 의한 스트레스 저항성 증강

Antisense construct of cDNA for senescence-related ACC oxidase (CAO) cDNA isolated from carnation flowers were introduced into tobacco by Agrobacterium-mediated transformation. The decreasing expression of NtACO and the reduction of ethylene production were observed in these transgenic lines. In contrast, the SAMDC transcripts and spermidine content were increased. The findings that higher content of spermidine in the ethylene suppressed transgenic plants compared with wild-type should be directly resulted in the enhancement of SAMDC activity followed by the increased accumulation of SAMDC transcript. To investigate the pathogenic response in these transgenic plants, wild-type and transgenic plants were inoculated with Phytophthora parasitica pv. nicotianae. Transgenic plants suppressing ethylene production showed the increased resistance against fungal pathogen, comparing with wild-type plant. PR-protein genes expression in CAO-AS-2 and CAO-AS-4 were also higher at the normal growth condition and pathogenic response than in wild-type plants. The results of higher spermidine content and SAMDC activity in transgenic plants, CAO-AS-2 and CAO-AS-4, support the possibility that an increase in spermidine content might induce the higher transcripts of PR-protein genes. This results agreed with the phenomena that spermidine promoted the expression of PR1a and a SAMDC inhibitor, MGBG, decreased the expression of PR1a in leaf discs. These results suggest that the resistance against fungal pathogen in transgenic tobacco impaired in ethylene production might be caused by increasing in polyamine, especially spermidine, biosynthesis.

Postharvest nitric oxide fumigation alleviates chilling injury, delays fruit ripening and maintains quality in cold-stored ‘Kensington Pride’ mango

We investigated the effects of postharvest nitric oxide (NO) fumigation (0, 5, 10, 20 and 40 μL L −1) on chilling injury (CI), ripening and quality of mango ( Mangifera indica L. cv. Kensington Pride) during fruit ripening at 21 ± 1 °C. The fruit had been cold-stored at 5 ± 1 °C for either 2 or 4 weeks. NO treatments (10, 20 and 40 μL L −1) significantly alleviated the CI index in cold-stored fruit during ripening. All NO fumigation treatments significantly suppressed ethylene production and respiration rates irrespective of the cold storage period. NO fumigation of higher than 5 μL L −1 significantly delayed fruit softening up to 2 d and retarded colour development, and fumigation after 2 and 4 weeks of cold storage significantly delayed the increase in total sugar and fructose concentrations at the full ripe stage. All NO fumigation treatments significantly increased tartaric and shikimic acids during ripening in 2- and 4-week cold-stored fruit, except for the 5 μL L −1 treatment in 2-week stored fruit. NO fumigation treatments did not significantly influence the concentrations of sucrose, glucose, total acid, citric, malic, fumaric, ascorbic acid, carotenoids in pulp and total antioxidant (in pulp and skin), as compared to non-fumigated fruit in both storage periods. Averaged over NO concentrations, 2 weeks of cold storage resulted in significantly higher mean concentrations of total sugar, sucrose, fructose, tartaric acid, malic acid, total carotenoids and total antioxidants (skin) than in 4-week stored fruit and the trend was the reverse for total acids, citric, shikimic, and fumaric acid. In conclusion, postharvest application of NO (10, 20 and 40 μL L −1) alleviated CI, delayed fruit colour development, softening and ripening as well as maintained quality through reduction of ethylene production and respiration during ripening in 2- and 4-week cold-stored fruit.

Enhancement of growth and salt tolerance of red pepper seedlings (Capsicum annuum L.) by regulating stress ethylene synthesis with halotolerant bacteria containing 1-aminocyclopropane-1-carboxylic acid deaminase activity

Three 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase-producing halotolerant bacteria were isolated from West Coast soil of Yellow Sea, Incheon, South Korea and evaluated for their efficiency in improving red pepper plant growth under salt stress. The strains RS16, RS656 and RS111 were identified by 16S rRNA gene sequencing as Brevibacterium iodinum, Bacillus licheniformis and Zhihengliuela alba, respectively. Two hour exposure of 100, 150 and 200 mM NaCl stress on 8 day old red pepper seedlings caused 44, 64 and 74% increase ethylene production, while at 150 mM NaCl stress, inoculation of B. licheniformis RS656, Z. alba RS111, and Br. iodinum RS16 reduces ethylene production by 44, 53 and 57%, respectively. Similarly, 3 week old red pepper plants were subjected to salt stress for two weeks and approximately ∼50% reduction in growth recorded at 150 mM NaCl stress compared to negative control whereas bacteria inoculation significantly increase the growth compared to positive control. Salt stress also caused 1.3-fold reduction in the root/shoot dry weight ratio compared to the absence of salt while bacteria inoculation retained the biomass allocation similar to control plants. The salt tolerance index (ratio of biomass of salt stressed to non-stressed plant) was also significantly increased in inoculated plants compared to non-inoculated. Increase nutrient uptakes under salt stress by red pepper further evident that bacteria inoculation ameliorates salt stress effect. In summary, this study indicates that the use of ACC deaminase-producing halotolerant bacteria mitigates the salt stress by reducing salt stress-induced ethylene production on growth of red pepper plants.

Physiological and biochemical response of harvested plum fruit to oxalic acid during ripening or shelf-life

The effect of oxalic acid application on plum fruit (Prunus salicina cv. ‘Damili’) ripening properties during storage or shelf-life was determined. The fruits were dipped for 3min in solutions containing 5mmol/L oxalic acid and then were packed into polyethylene bags and stored at 25°C for 12days, or at 2°C for 20days and subsequently at 25°C for 12days. Ethylene production, fruit firmness, contents of pectin and anthocyanin, specific activities of polygalacturonase (PG), pectin methylesterase (PME) and phenylalanine ammonia lyase (PAL), and chlorophyll fluorescence (Fv/Fm) were measured. The application of oxalic acid reduced ethylene production and delayed softening of plum fruit. The inhibition of softening was associated with decreased PG and PME activities; that is, the retardation of pectin solubilization/degradation. During storage or shelf-life, flesh reddening and anthocyanin synthesis were significantly inhibited in oxalic acid-treated plum fruit, accompanied with decreased PAL activity. Furthermore, it was found that variable:maximalchlorophyll fluorescence (Fv/Fm), an indicator of ripening, senescence or stress injury of fruit and vegetable, decreased much more slowly in oxalic-treated plum fruits than in control fruits. Thus, oxalic acid treatment can be an effective means to extend the shelf life of plum fruit.

Isolation, Characterization, and Use for Plant Growth Promotion Under Salt Stress, of ACC Deaminase-Producing Halotolerant Bacteria Derived from Coastal Soil

In total, 140 halotolerant bacterial strains were isolated from both the soil of barren fields and the rhizosphere of six naturally growing halophytic plants in the vicinity of the Yellow Sea, near the city of Incheon in the Republic of Korea. All of these strains were characterized for multiple plant growth promoting traits, such as the production of indole acetic acid (IAA), nitrogen fixation, phosphorus (P) and zinc (Zn) solubilization, thiosulfate (S2O3) oxidation, the production of ammonia (NH3), and the production of extracellular hydrolytic enzymes such as protease, chitinase, pectinase, cellulase, and lipase under in vitro conditions. From the original 140 strains tested, on the basis of the latter tests for plant growth promotional activity, 36 were selected for further examination. These 36 halotolerant bacterial strains were then tested for 1- aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. Twenty-five of these were found to be positive, and to be exhibiting significantly varying levels of activity. 16S rRNA gene sequencing analyses of the 36 halotolerant strains showed that they belong to 10 different bacterial genera: Bacillus, Brevibacterium, Planococcus, Zhihengliuella, Halomonas, Exiguobacterium, Oceanimonas, Corynebacterium, Arthrobacter, and Micrococcus. Inoculation of the 14 halotolerant bacterial strains to ameliorate salt stress (150 mM NaCl) in canola plants produced an increase in root length of between 5.2% and 47.8%, and dry weight of between 16.2% and 43%, in comparison with the uninoculated positive controls. In particular, three of the bacteria, Brevibacterium epidermidis RS15, Micrococcus yunnanensis RS222, and Bacillus aryabhattai RS341, all showed more than 40% increase in root elongation and dry weight when compared with uninoculated saltstressed canola seedlings. These results indicate that certain halotolerant bacteria, isolated from coastal soils, have a real potential to enhance plant growth under saline stress, through the reduction of ethylene production via ACC deaminase activity.

THE ROLE OF PROLYL 4-HYDROXYLASES IN TOMATO FRUIT RIPENING

Fruit ripening comprises a wide range of molecular and biochemical processes which lead to changes in texture, color, flavor and aroma. Ethylene coordinates most of these programmes according to extensive studies mainly on tomato which is the model system for fruit ripening. Gene expression analysis shows that tomato P4Hs have different patterns of expression during fruit ripening. Treatment of tomato pericarp discs at turning and light red stage of development with 2,4-pyridine dicarboxylate (PDCA), an inhibitor of prolyl 4-hydroxylases, resulted in reduced ethylene production and alterations in expression of arabinogalactan proteins (AGPs). However, there is no available information up to now linking AGPs and ethylene regulation. Analysis of the transcript levels of the major ACO genes, showed that PDCA down-regulated the expression of SIACO4. The role of P4Hs and AGPs in fruit ripening is currently under investigation.

EFFECT OF MATURITY AND 1-MCP ON PHYSIOLOGY OF TOMATO SLICES

ISHS International Symposium Postharvest Pacifica 2009 - Pathways to Quality: V International Symposium on Managing Quality in Chains + Australasian Postharvest Horticultural Conference EFFECT OF MATURITY AND 1-MCP ON PHYSIOLOGY OF TOMATO SLICES

The effects of 1-MCP in cyclodextrin-based nanosponges to improve the vase life of Dianthus caryophyllus cut flowers

The present research investigated the effects of a non-volatile formulation of 1-methylcyclopropene (1-MCP) embedded in different cyclodextrin (CD)-based nanosponges (NSs) to extend the postharvest longevity of an ethylene-sensitive carnation cultivar. Cut flowers of Dianthus caryophyllus L. ‘Idra di Muraglia’ were treated with α- and β-CD-based nanosponge-1-MCP complexes (α- and β-NS complexes) in tap water to achieve two different concentrations of active ingredient (0.25 and 0.5 μL L −1). Treated flowers were compared to cut stems exposed to equivalent concentrations of volatile 1-MCP as well as a tap water control with or without pure α- and β-NS. Identical nanoporous compounds were applied by perfusion to yield a total of 15 treatments. Twenty-four hours after the treatments were applied, the cut flowers were exposed to exogenous ethylene (1 ± 0.2 μL L −1) for 24 h. The postharvest carnation flower and leaf quality in addition to ethylene production levels were determined daily (beginning 24 h after treatment). None of the α-NS complex applications statistically improved the vase life of cut flowers; however, β-NS complexes were effective in preventing senescence, reducing ethylene production (measured at nearly nil after 11 d), and maintaining original petal color longer. These results were particularly strong at the lowest concentration (0.25 μL L −1) of β-NS complex. Overall, this method promoted cut flower longevity (loss of ornamental value after 14.7 d; complete damage at day 18.5) better than the commercial 1-MCP gaseous application method.

IMPROVEMENT OF PLUM STORAGE WITH MODIFIED ATMOSPHERE PACKAGING

Post-harvest supply chain is a critical point for agro-food marketing. The management of freshness in the storage is fundamental to maintain high profits in the agro-food sector to improve the distribution and to respond to retailers and consumers' requirements. Plums are considered to have a climacteric-ripening pattern, in which ethylene is the hormone responsible for ripening. Modified atmosphere (MA) storage is a method helpful to maintain the natural quality of fruits. MA added to low temperatures influence fruit metabolism and reduce ethylene production, weight losses, hardness of pulp, preserving vitamins and organic acids. The objective of this study was to increase the condition of storage and the shelf life of different plum cultivars through the use of MA and different types of plastic film. Considered units are commercial pallets with large batches of product and individual basket units. Qualitative destructive analysis to determine weight losses, total sugar, and acidity titratable were made to compare samples stored in MA and test mantained in normal atmosphere at 0°C.