Chlorine dioxide treatment decreases respiration and ethylene synthesis in fresh‐cut ‘Hami’ melon fruit

The effects of chlorine dioxide (ClO₂) on respiration and ethylene synthesis of fresh‐cut melon fruit and the possible mechanisms involved were investigated. Fresh‐cut ‘Hami’ melon fruit fumigated with gas ClO₂ in sealed container for 12 h and then stored at 5 °C with 95% relative humidity (RH) for 19 days. Results showed that fruit treated with ClO₂ resulted in lower rates of the total respiration, alternative pathway respiration, cytochrome pathway respiration and ethylene production. Furthermore, the expressions of ethylene biosynthesis‐related genes, including CmACS2, CmACO1 and CmACO3 were reduced by ClO₂ treatment. Taken together, it is suggested that ClO₂ treatment might be an effective way to delay ripening of fresh‐cut ‘Hami’ melon, partially due to the reduced respiration and ethylene biosynthesis.     

INFLUENCE OF ATMOSPHERIC OXYGEN AND OZONE ON RIPENING INDICES OF NORMAL (Rin) AND RIPENING INHIBITED (rin) TOMATO CULTIVARS1

ABSTRACT Ethylene (10ppm) dependent mediation of normal and mutant (rin) tomato fruit ripening was promoted by 100%oxygen, 3.7 pphm ozone, or their combination. All ripening indices studied (respiration, chlorophyll degradation, carotenoid accumulation, softening, and aroma development) were promoted by oxygen and/or ozone. Ozone also acted independent of ethylene in promoting chlorophyll degradation and aroma development in normal fruit, but did not appreciably affect these quality attributes in mutant fruit. Lycopene accumulation in normal and mutant fruit and aroma formation in normal fruit were promoted to a greater extent by ozone than were other ripening indices. Mutant (rin) fruit contained 27% of the lycopene that was present in normal (Rin) fruit after ripening in O₂ containing 10ppm ethylene and 3.7 pphm ozone, whereas they contained only 3%of the lycopene in normal fruit after ripening in air containing 10ppm ethylene.     

The Role of Ethylene in the Regulation of Fruit Ripening in the Hillawi Date Palm ( Phoenix dactyliferaL)

The role of ethylene in the regulation of fruit ripening in the date palm ( Phoenix dactylifera L) was investigated. It was found that the rate of CO₂ output was high initially, but the rate declined steadily as the fruit advanced in maturity, reaching its lowest level as the fruit entered the stage of physiological maturity, but then the rate of respiration increased as the fruit entered the ripening phase, reached a peak value and then declined. Ethylene emission was not detected until the 91st day from pollination when ethylene production began with a rapid increase in emission, reaching a peak value within 15 days and then declining rapidly. The peak of ethylene production preceded the climacteric peak by 7 days.     

Decrease in Fruit Moisture Content Heralds and Might Launch the Onset of Ripening Processes

Abstract: It is known that fruit ripening is a genetically programmed event but it is not entirely clear what metabolic cue(s) stimulate the onset of ripening, ethylene action notwithstanding. Here, we examined the conjecture that fruit ripening might be evoked by an autonomously induced decrease in tissue water status. We found decline in water content occurring at the onset of ripening in climacteric and nonclimacteric fruit, suggesting that this phenomenon might be universal. This decline in water content persisted throughout the ripening process in some fruit, whereas in others it reversed during the progression of the ripening process. Applied ethylene also induced a decrease in water content in potato (Solanum tuberosum) tubers. In ethylene‐mutant tomato (Solanum lycopersicum) fruit (antisense to1‐aminocyclopropane carboxylate synthase), cold‐induced decline in water content stimulated onset of ripening processes apparently independently of ethylene action, suggesting cause‐and‐effect relationship between decreasing water content and onset of ripening. The decline in tissue water content, occurring naturally or induced by ethylene, was strongly correlated with a decrease in hydration (swelling) efficacy of cell wall preparations suggesting that hydration dynamics of cell walls might account for changes in tissue moisture content. Extent of cell wall swelling was, in turn, related to the degree of oxidative cross‐linking of wall‐bound phenolic acids, suggesting that oxidant‐induced wall restructuring might mediate cell wall and, thus, fruit tissue hydration status. We propose that oxidant‐induced cell wall remodeling and consequent wall dehydration might evoke stress signaling for the onset of ripening processes. Practical Application: This study suggests that decline in fruit water content is an early event in fruit ripening. This information may be used to gauge fruit maturity for appropriate harvest date and for processing. Control of fruit hydration state might be used to regulate the onset of fruit ripening.     

Expression of genes associated with ethylene-signalling pathway in harvested banana fruit in response to temperature and 1-MCP treatment

BACKGROUND: Little attention has been paid to characterising the ethylene‐signalling pathway genes in relation to abnormal ripening of harvested banana fruit during storage at high temperature. The aim of the present study was to investigate banana fruit abnormal ripening and the expression of ten genes associated with the ethylene‐signalling pathway, namely MaACS1, MaACO1, MaERS1–4 and MaEIL1–4, at high temperature. Changes in these parameters of banana fruit at high temperature in response to 1‐MCP pretreatment were also investigated. RESULTS: High temperature accelerated the decline in fruit firmness, increased ethylene production and inhibited degreening in banana fruit, resulting in fruit abnormal ripening. In addition, the expression of MaACS1, MaACO1, MaERS2, MaERS3, MaERS4, MaEIL1, MaEIL3 and MaEIL4 was enhanced in banana fruit stored at high temperature. However, application of 1‐MCP prior to high temperature storage delayed fruit abnormal ripening and simultaneously suppressed the expression of MaACS1, MaERS2, MaERS3, MaEIL1, MaEIL3 and MaEIL4. CONCLUSION: The findings of this study suggested that the expression of genes associated with the ethylene‐signalling pathway might be involved in banana fruit abnormal ripening at high temperature. Application of 1‐MCP suppressed the expression of genes associated with the ethylene‐signalling pathway, which may be attributed at least partially to 1‐MCP delaying fruit abnormal ripening at high temperature. Copyright © 2010 Society of Chemical Industry     

Reducing ethylene levels along the food supply chain: a key to reducing food waste?

Excessive waste along the food supply chain of 71 (UK, Netherlands) to 82 (Germany) kg per head per year sparked widespread criticism of the agricultural food business and provides a great challenge and task for all its players and stakeholders. Origins of this food waste include private households, restaurants and canteens, as well as supermarkets, and indicate that 59–65% of this food waste can be avoided. Since ～50% of the food waste is fruit and vegetables, monitoring and control of their natural ripening gas – ethylene – is suggested here as one possible key to reducing food waste. Ethylene accelerates ripening of climacteric fruits, and accumulation of ethylene in the supply chain can lead to fruit decay and waste. While ethylene was determined using a stationary gas chromatograph with gas cylinders, the new generation of portable sensor‐based instruments now enables continuous in situ determination of ethylene along the food chain, a prerequisite to managing and maintaining the quality and ripeness of fruits and identifying hot spots of ethylene accumulation along the supply chain. Ethylene levels were measured in a first trial, along the supply chain of apple fruit from harvest to the consumer, and ranged from 10 ppb in the CA fruit store with an ethylene scrubber, 70 ppb in the fruit bin, to 500 ppb on the sorting belt in the grading facility, to ppm levels in perforated plastic bags of apples. This paper also takes into account exogenous ethylene originating from sources other than the fruit itself. Countermeasures are discussed, such as the potential of breeding for low‐ethylene fruit, applications of ethylene inhibitors (e.g. 1‐MCP) and absorber strips (e.g. ‘It's Fresh’, Ryan'), packages (e.g. ‘Peakfresh’), both at the wholesale and retail level, vents and cooling for the supply chain, sale of class II produce (‘Wunderlinge’), collection (rather than waste) of produce on the ‘sell by’ date (‘Die Tafel’) and whole crop purchase (WCP) to aid reducing food waste. © 2014 Society of Chemical Industry     

Application of vacuum and exogenous ethylene on Ataulfo mango ripening

The limited industrial processing and export to European countries of fresh Mexican ‘Ataulfo’ mangoes is attributed in part to the lack of homogeneous ripening among fruit from the same lot. A viable technology to alleviate the situation is the application of exogenous ethylene. In this work, vacuum (34 kPa) was applied for 20 min to ‘Ataulfo’ mangoes that were later exposed to exogenous ethylene (500, 1000 and 1500 μL L⁻¹) for 30 min and ripening was monitored. Application of vacuum did not produce apparent visual damage to the fruit; when 1500 μL L⁻¹ ethylene were applied for 30 min after the vacuum, induced production of internal ethylene with a concomitant increase in respiration rate. Firmness and acidity loss proceeded faster after the fruits were exposed to vacuum and 1500 μL L⁻¹ ethylene; similarly, total soluble solids increased and pulp and peel color development was 100% in the whole lot. An overall reduction of three days from the normal ripening time was observed attributed to the treatments. It is proposed that short exposures to vacuum and ethylene could improve the uniformity in mango ripening.     

Effects of 1‐methylcyclopropene and gibberellic acid on ripening of Chinese jujube (Zizyphus jujuba M) in relation to quality

Overripening of Chinese jujube (Zizyphus jujuba M) fruit at the postharvest stage usually results in a dramatic decline in quality. The role of 1‐methylcyclopropene (1‐MCP) and gibberellic acid (GA) in fruit ripening of Chinese jujube during storage in relation to quality was investigated. Fruit ripening of jujube was significantly enhanced by ethylene, whereas rates of respiration and ethylene production of the fruit were reduced by 1‐MCP. Treatment with 1‐MCP or GA delayed the decreases in firmness and vitamin C and reduced the level of ethanol. Furthermore, the effectiveness of 1‐MCP was improved by replicate treatments during storage at 20 or 2 °C. In addition, treatment with GA + 1‐MCP resulted in additive beneficial effects on ripening inhibition of the fruit. Copyright © 2003 Society of Chemical Industry     

QUALITY OF APPLE FRUIT IN RIGID FILM CONTAINERS

The storage quality of‘Delicious’ apples individually packaged in rigid film containers was investigated. Objective quality attributes (internal and external color, firmness, soluble solids and titratable acidity) were measured as a function of storage time with and without packaging in a rigid container. Overall firmness, acidity and soluble solids content decreased over a 70-day storage period. Significant effects of rigid film packaging and storage included: superior skin color, decreased weight loss, slight decrease in soluble solids content and increased firmness loss during ripening when compared to control fruit. Upon examination of the atmosphere surrounding individual fruit in these containers, increased levels of carbon dioxide and ethylene were found. Conversely, packaged fruit contained significantly less internal carbon dioxide than control samples. It was concluded that the atmosphere modified by the rigid film container hastened ripening of‘Delicious’ apples, thus deteriorating eating quality. An adequately ventilated packaged would probably alleviate this condition.     

PRECONDITION OF 'D' ANJOU' PEARS FOR EARLY MARKETING BY ETHYLENE TREATMENT

'D' Anjou' pears (Pyrus communis, L.) harvested at an optimum maturity with the flesh firmness (FF) of 66.7N required 8 weeks of chilling at- 1C in order to initiate normal ripening in an ethylene-free environment at room temperature. If harvested fruit were not exposed to chilling or chilled at- 1C for less than 8 weeks, they could be preconditioned with 100 ppm ethylene for 3 days at 20C to initiate normal ripening. Fruit preconditioned with ethylene were capable of softening normally, reducing extractable juice, decreasing titratable acidity, and showing the climacteric rise of ethylene production during ripening at 20C when treated fruit had been further held at -1C in air for 14 days. The properly ripened fruit developed an acceptable dessert quality. When ‘d'Anjou’fruits had been stored at -1C in air for 8 weeks or longer, they could also be preconditioned without ethylene for 3 days at 20C to enhance ripening capacity. The nonethylene preconditioned fruit were capable of ripening normally following 14 days in simulated transit at -1C and upon arrival in retail markets at room temperature.     

Chinese gooseberry: Seasonal patterns in fruit growth and maturation,ripening, respiration and the role of ethylene

Fruits of Chinese gooseberry (Actinidia chinensis Planchon, cv. Bruno) were harvested and respiration rates and other attributes were measured at regular intervals throughout the season. The fruit matured at about 23 weeks after anthesis as shown by patterns of respiration, response to ethylene treatment and changes in texture and content of soluble solids. Fruit growth followed a unique triple sigmoid curve. Natural ripening showed the fruits to be of climacteric type but, although associated with a peak of ethylene production, the respiratory pattern was somewhat atypical and initiation of ripening within any lot of uniform fruits was very variable. Ethylene treatment stimulated ripening in fruits of all ages, but a large induced respiratory peak was seen only in immature fruits. The physiological observations confirmed present horticultural practices and provide a basis for development of objective enforceable quality grades.     

Lipoxygenase activity associated to fruit ripening and senescence in chayote (Sechium edule Jacq. Sw. cv. “virens levis”)

Lipoxygenase (LOX) enzyme activity and their putative isoforms were investigated during postharvest life in chayote fruit (Sechium edule Jacq. Sw. cv. “virens levis”). Possible associations of LOX with fruit quality parameters are discussed. Five LOX isoforms were identified (SeLOX‐1 to ?5) displaying different activity patterns during ripening and senescence as well as in roots, stems, and leaves. The probable role of SeLOX‐5 as a specific isoform linked to senescence was examined. The highest relative activity of LOX was registered in fruit tissue, followed by leaves, stem, and roots. Correlations were found between LOX and fruit composition variables such as the contents of linoleic (LA) and linolenic (LNA) acids, weight loss, CO₂ and ethylene production rates. LOX activity, and LA and LNA concentration decreased from Day 1 to Days 13–17, when early seed germination events became visible, indicating a transition stage between late fruit ripening and early senescence characterized by a deteriorative process.

Practical applications

Detrimental effects on fruit composition variables such as dehydration, weight loss, wilting, and sprouting symptoms, have been reported as the main causes that reduce the commercial quality and shelf life in chayote fruit and prevent their export to distant markets. To the best of our knowledge, the association of lipoxygenase (LOX) enzymes to non‐climacteric fruit ripening—like chayote—or their loss of commercial quality during prolonged shelf life has not yet been described. This is the first study that explores the role of chayote LOX activity in fruit, identifies various specific LOX isoforms associated to ripening or to the senescence process and provides new evidence that supports the hypothesis that putative LOX isoforms might be related to several postharvest detrimental effects on chayote fruit. This information could be useful to food processors or packers to pursue better profitability and consumer satisfaction.     

ACTIVITIES OF β-GALACTOSIDASE AND α-L-ARABINOFURANOSIDASE, ETHYLENE BIOSYNTHETIC ENZYMES DURING PEACH RIPENING AND SOFTENING

A study was conducted to determine changes in firmness, ethylene and ethylene biosynthetic enzymes, and the activities of β‐galactosidase (β‐GAL) and α‐L‐arabinofuranosidase (α‐AF) during peach ripening and softening. The activities of 1‐aminocyclopropane‐1‐carboxylic acid (ACC) synthase, ACC oxidase and polygalacturonase increased in parallel with ethylene production and declined in firmness during peach ripening, and they appeared at maximum simultaneously at maturity IV. β‐GAL activity was high in unripe peach fruit and it experienced an overall decline during peach ripening. While α‐AF activity changed placidly at the initial stage (maturity I–III), after that it experienced a rapid increasing stage. The preliminary result indicated that β‐GAL and α‐AF, as well as ethylene biosynthetic enzymes, may be involved in the ripening and softening of peach fruit.     

Determination of optimum harvest maturity and physico-chemical quality of Rastali banana (Musa AAB Rastali) during fruit ripening

BACKGROUND: A series of physico‐chemical quality (peel and pulp colours, pulp firmness, fruit pH, sugars and acids content, respiration rate and ethylene production) were conducted to study the optimum harvest periods (either week 11 or week 12 after emergence of the first hand) of Rastali banana (Musa AAB Rastali) based on the fruit quality during ripening. RESULT: Rastali banana fruit exhibited a climacteric rise with the peaks of both CO₂ and ethylene production occurring simultaneously at day 3 after ripening was initiated and declined at day 5 when fruits entered the senescence stage. De‐greening was observed in both of the harvesting weeks with peel turned from green to yellow, tissue softening, and fruits became more acidic and sweeter as ripening progressed. Sucrose, fructose and glucose were the main sugars found while malic, citric and succinic acids were the main organic acids found in the fruit. CONCLUSION: Rastali banana harvested at weeks 11 and 12 can be considered as commercial harvest period when the fruits have developed good organoleptic and quality attributes during ripening. However, Rastali banana fruit at more mature stage of harvest maturity taste slightly sweeter and softer with higher ethylene production which also means the fruits may undergo senescence faster than fruit harvested at week 11. Copyright © 2011 Society of Chemical Industry     

Bananas — physiology and biochemistry of storage and ripening for optimum quality

Bananas (Musa spp.) are a major food crop of the humid tropics, and though edible cultivars are diverse and numerous, most of our knowledge of the physiology and biochemistry of these fruits relates to a few dessert cultivars of the AAA type, mainly of the Cavendish subgroup, which dominate the export trade between tropical and temperate zones. The preclimacteric period of banana fruits after harvest determines their transportability, and its duration is very sensitive to changes in fruit maturity, storage temperature, ethylene concentration, and other factors; progress in measurement and resolution of each of these effects is described. Changes in composition of the ripening fruits, especially in the development of flavor volatiles, are reviewed. Progress in understanding the integration of the biochemical changes controlling ripening in banana fruits is discussed. Recent work on storage, ripening, and factors relating to sensory assessment of fruit quality is discussed for cultivars of Musa types not used in major export trades.     

温度和乙烯对京白梨后熟进程及其品质的影响

研究温度、乙烯对京白梨果实后熟进程及品质的影响。测定果实乙烯释放量、呼吸强度、果实硬度、可溶性固形物含量、pH值、果皮颜色ΔE 值和h 值、失重率、病果率等指标,并进行感官评价。结果表明：温度和乙烯直接影响果实的后熟进程和后熟品质;后熟过程中果实硬度与后熟时间呈极显著线性负相关(P＜ 0.01),温度过高或过低均导致果皮转色和果实硬度后熟不一致,适度的低温(14℃)延迟了果实乙烯峰值的启动时间,高温(28℃)抑制乙烯的生成和果实的软化,温度越高,失重率和烂果率越高;外源乙烯有助于果实乙烯的生成和呼吸强度的增加,乙烯加快了果实的后熟进程,并且后熟更均匀一致,且品质最佳。研究表明：京白梨后熟的适宜温度范围17～23℃,最佳温度20℃,最佳乙烯催熟用量为100μL/L。     

Classification of bananas during ripening using peel roughness analysis—An application of atomic force microscopy to food process

To monitor banana surface (peel) roughness changes during ripening treatment, atomic force microscopy (AFM) as a novel and emerging technique was used in this study. The roughness of banana peel was studied using the arithmetic mean between peaks and troughs (R_a) and the root-mean-square roughness (R_q). It was concluded that with changing the ripening stages, the behavior of the roughness changes significantly. With advancing fruit ripening, the extending of the epicarp and the decrease of the surface (peel) roughness were found due to enlarging of fruit volume. The highest mean roughness was found to be at stage 1, R_a = 8.25 and R_q = 9.65 nm. Based on two-dimensional profile results, the surface (peel) roughness was affected strongly by studied different ripening stages. It was concluded that the peak values in the ripple profiles become smaller with advancing fruit ripening. However, the effects of noise in the profiles appeared to increase. So, in all the initial stages of banana fruit ripening, the noise was found to be minimal. Consequently, the AFM technique was found to be a promising tool for quantification of the peel roughness or glossiness and also could help in the quality control of banana fruit on the nanoscale.     

Effect of pre‐ripening chilling temperatures on ripening,shelf life and quality of bananas treated with 1‐methylcyclopropene

Ethylene production, shelf life and fruit quality of Cavendish bananas (cv. Williams), held at different pre‐ripening storage temperatures (5 °C, 10 °C or 15 °C) prior to ethylene and/or 1‐methylcyclopropene (1‐MCP) application, were determined and compared. Levels of ethylene production during ripening were highest for control fruit that had been stored at 5 °C followed by 10 °C and then 15 °C. 1‐MCP treatment (at 300 nL L^?1) had no effect on ethylene production of fruit that had been stored at 10 °C by day 10 of storage, but ethylene production was significantly higher for fruit that had been stored at 15 °C and lower for those stored at 5 °C before 1‐MCP treatment. 1‐MCP also increased shelf life to a greater extent when applied to fruit that had been stored at 10 °C or 15 °C. Even though 1‐MCP had no significant effect on under peel chilling injury, it increased discolouration significantly, regardless of storage temperature. Firmness of 1‐MCP‐treated fruit decreased significantly compared to the control when fruit were held at 5 °C or 15 °C prior to ripening (and 1‐MCP application) but had no effect on fruit stored at 10 °C before ripening. These results indicate that pre‐ripening storage temperature affects ripening, shelf life and quality in both ethylene and 1‐MCP‐treated bananas.     

INHIBITION OF RIPENING AND INDOLE-3-ACETIC ACID OXIDASE OF BANANA FRUIT BY p-2,4-CHLOROPHENOXY-ISOBUTYRIC ACID

p-2,4-dichloro-phenoxy-isobutyric acid (p-CPIB) was observed to repress the ripening of green banana fruit after injection into the peel-pulp juncture at concentrations ranging from 10⁻⁵ to 10⁻³M. Application of 10⁻²M p-CPIB resulted in rapid necrosis at the site of injection and accelerated ripening at distal areas of the banana. Repression of ripening occurred regardless of whether fruit were gassed with exogenous ethylene. Indole-3-acetic acid oxidase isolated from the pulp of banana fruit was inhibited by concentrations of p-CPIB which repressed ripening. In addition, injection of indole 3-acetic acid and 2,4-dichlorophenoxy acetic acid into the peel-pulp juncture delayed ripening for up to 15 days at 10⁻³M. It is suggested the p-CPIB affected ripening in banana fruit by blocking the oxidative metabolism of endogenous auxins