Effect of ripeness and postharvest storage on the evolution of colour and anthocyanins in cherries (Prunus avium L.)

The relationship between colour parameters and anthocyanins of four sweet cherry cultivars, Burlat, Saco, Summit and Van was studied. The colour (L^∗, a^∗, b^∗, chroma and hue angle parameters) and anthocyanins were analysed during two different years at two different ripening stages (partially ripe, and ripe, respectively). The cherries were analysed at harvest and after storage at 1.5 ± 0.5 °C and 15 ± 5 °C for 30 and 6 days, respectively. The colour was measured by tristimulus colourimetry (CIELAB system) directly on the fruits, while anthocyanins were quantified by HPLC-DAD analysis on methanolic extracts of freeze-dried samples of the fresh cherries and on the differently stored cherries. L^∗, chroma, and hue angle values were always lower for the ripe than for the partially ripe cherries. All of the cultivars were found to contain cyanidin-3-rutinoside and cyanidin-3-glucoside as the major anthocyanins. The total anthocyanin content in fruits of the different cultivars varied in the order Burlat > Saco > Van > Summit. The concentration of anthocyanins increased at both temperatures of storage in both ripe and partially ripe cherries, but the extent of increase varied among cultivars. Cherries stored at 15 ± 5 °C showed higher reduction of L^∗, chroma and hue angle than fruits stored at 1.5 ± 0.5 °C. L^∗, a^∗, b^∗, chroma and hue angle correlated negatively (P < 0.001) with the total anthocyanins levels, but not with the total phenols. These results show that chromatic functions of chroma and hue correlate closely with the evolution of colour and anthocyanins levels during storage of sweet cherries and indicate that colour measurements can be used to monitor pigment evolution and anthocyanin contents of cherries (and vice versa).     

Changes of anthocyanins and hydroxycinnamic acids affecting the skin colour during maturation of sweet cherries (Prunus avium L.)

The content and relative amounts of anthocyanins and hydroxycinnamic acids (HCA) were determined in local sweet cherries (cultivar Petrovka) at 7 stages of maturity, by means of high performance liquid chromatography (HPLC), and compared to instrumentally assessed skin colour of the same sweet cherries. Skin colour of harvested samples was measured using the CIE L^*,a^*,b^* system. The contents of neochlorogenic and 3′-p-coumarylquinnic acids decreased with no significant change in ratio during ripening, except for the first 4 days of maturation, when the ratio changed due to increased content of neochlorogenic acid. The linear increase of total anthocyanins during maturation was observed without the trend of stabilization in the final stages of maturity. The colour change of Petrovka during maturation was influenced by the increase of total anthocyanins, consisting mostly of cyanidin-3-rutinoside and cyanidin-3-glucoside (97-98% of the total). The chroma and L^* values appeared to be optimal indicators of anthocyanin accumulation during maturation, and better than the a^* value and hue angle. The accumulation of anthocyanins from 507.1 to 1150.9 mg of cyanidin-3-rutinoside/kg of fresh weight (FW) during the second half of maturation caused the formation of a new colour cast of Petrovka, which influenced the decrease of redness and colour intensity, as recognized by CIE L^*,a^*,b^* colour space.     

Fruit quality and bioactive compounds relevant to human health of sweet cherry (Prunus avium L.) cultivars grown in Italy

The fruit quality characteristics, phenolic compounds and antioxidant capacities of 24 sweet cherry (Prunus avium L.) cultivars grown on the mountainsides of the Etna volcano (Sicily, Italy) were evaluated. High-performance liquid chromatographic methods were used to identify and quantify sugars, organic acids and phenolics. A total of seven phenolic compounds were characterised as hydroxycinnamic acid derivatives (neochlorogenic acid, p-coumaroylquinic acid and chlorogenic acid) and anthocyanins (cyanidin 3-glucoside, cyanidin 3-rutinoside, pelargonidin 3-rutinoside and peonidin 3-rutinoside). The total anthocyanin content ranged from 6.21 to 94.20 mg cyanidin 3-glucoside equivalents/100 g fresh weight (FW), while the total phenol content ranged from 84.96 to 162.21 mg gallic acid equivalents/100 g FW. The oxygen radical absorbance capacity (ORAC) assay indicated that fruit of all genotypes possessed considerable antioxidant activity. The high level of phenolic compounds and antioxidant capacity of some sweet cherry fruits implied that they might be sources of bioactive compounds that are relevant to human health.     

Variety–compound–quality relationship of 12 sweet cherry varieties by HPLC-chemometric analysis

In this study, 12 sweet cherry varieties grown in Shandong (China) were compared based on their quality indices and high performance liquid chromatography (HPLC) fingerprints, along with chemometric discrimination by similarity analysis, hierarchical clustering analysis and principal component analysis. The established sample preparation and analysis methods represented a non-targeted and practical approach with reasonably high sensitivity, precision, stability and reproducibility, providing comprehensive evaluation of the quality of sweet cherries while allowing the tentative classification of cherry varieties. The results revealed the variety-dependent nature of the HPLC fingerprints of sweet cherries, and the fruit groupings according to their chemical composition (three groups based on phenolics, or four groups if organic acids were of main interest). All cherries were rich in organic acids, hydroxycinnamic acids, hydroxybenzoic acids, anthocyanins, flavan-3-ols, flavonols and other flavonoids, with malic acid, cyanidin-3-O-rutinoside, p-coumaroylquinic acid, neochlorogenic acid and rutin as the characteristic compounds (in the range of 0.57–1.80, 0.002–1.390, 0.370–3.083, 0.38–1.87 and 0.020–0.167 mg g⁻¹ fruit fresh weight, respectively). While anthocyanin and flavonol patterns were useful for a varietal assignment of cherries, cyanidin-3-O-rutinoside could represent a preliminary index for grouping similar cultivars and colours.     

Total Anthocyanins and Total Phenolics of Fresh and Processed Cherries and Their Antioxidant Properties

ABSTRACT: Total anthocyanins, total phenolics, and the antioxidant activities of 1 sour cherry cultivar ( Prunus cerasus L.) and 3 sweet cherry cultivars ( P. avium L.) were determined. Bing cherries were highest in anthocyanins, whereas Montmorency cherries were highest in total phenolics and antioxidant activities (oxygen radical absor-bance capacity and ferric reducing antioxidant power). Total phenolics and anthocyanins for all cultivars were concentrated in the skin. More than 75% of anthocyanins in frozen Bing cherries were destroyed after 6 mo of storage at -23°C. During canning, about half the anthocyanins and polyphenolics leached from the fruits into the syrup with little total loss. Spent cherry brine contained substantial anthocyanins and polyphenolics.     

Anthocyanin and Polyphenolic Composition of Fresh and Processed Cherries

ABSTRACT: The distribution of anthocyanin pigments and polyphenolics in 1 sour cherry ( Prunus cerasus ) and 3 sweet cherry ( Prunus avium ) cultivars was determined by high-performance liquid chromatography with diode array detection. Changes during frozen storage, canning, and brining were also monitored. Sweet cherry cultivars differed qualitatively with respect to the minor anthocyanins. Hydroxycinnamates are the major class of polyphenolics in sweet cherries, whereas flavanols are in the majority in Montmorency cherries. Hydroxycinnamates were greatly affected by processing and storage, whereas flavonol glycosides were quite stable. Half of the anthocyanins and polyphenolics were transferred to the syrup with canning, and nearly all were transferred to brine during brining.     

Modelling the effect of different sterilisation treatments on antioxidant activity and colour of carrot slices during storage

The effect of F₀ treatment time (min) and storage on the antioxidant activity and Hunter colour parameters (L*, a*, b*) of carrot slices was investigated. Carrot slices were sterilised for 0 (control), 3, 15 and 50 min and subsequently stored for 0, 3 and 6 months. Significant differences were observed in colour values of carrot slices with no significant difference beyond F₀ treatment of 3 min. Regression modelling was used to investigate the main effects of treatment time and storage. Treatment time and storage period was found to be significant. Predicted models were found to be significant (p < 0.05) with low standard error and high coefficients of determination (R²). This study proposes the predicted models for quality parameters of sterilised carrot slices.     

Antiproliferative effects of cherry juice and wine in Chinese hamster lung fibroblast cells and their phenolic constituents and antioxidant activities

Cherries are good sources of bioactive phenolic compounds that are widely considered to be potentially healthy. Here we investigated the protective activities of juice and wine products of tart and sweet cherries and their constituent anthocyanins (e.g., cyanidin 3-glucoside and cyanidin 3-rutinoside) against oxidative stress induced by hydrogen peroxide (H₂O₂) in Chinese hamster lung fibroblasts (V79-4). Total phenolics in the cherry juices and wines were 56.7–86.8 mg of gallic acid equivalents (GAE)/l and 79.4–149 mg GAE/l, respectively. Total anthocyanins in the cherry juices and wines were 7.9–50.1 mg of cyanidin 3-glucoside equivalents (CGE)/l and 29.6–63.4 mg CGE/l, respectively. Both cherry juices and wines exerted protective effects against oxidative stress induced by H₂O₂ on V79-4 cells and also enhanced the activities of antioxidative enzymes, such as superoxide dismutase and catalase, in a dose-dependent manner. The protection of V79-4 cells from oxidative stress by phenolics was mainly attributable to anthocyanins. The positive correlation between the protective effects against oxidative stress in V79-4 cells and the antioxidant enzyme activities was stronger for cyanidin 3-glucoside than for cyanidin 3-rutinoside.     

1-Methylcyclopropene delays arazá ripening and improves postharvest fruit quality

Six different experiments were conducted to give some practical recommendation to apply 1-MCP during the postharvest handling chain of arazá fruit (Eugenia stipitata McVaugh). Fruit were harvested in three stages of maturity (mature-green primarily, turning and mature) and treated for 1 to 12 h with 0 (control in air) or 1 μL L⁻¹ 1-Methylcyclopropene (1-MCP) at 20 °C. The mature-green fruit were subjected to different storage conditions (7, 10, 12, 13, 20 or 27 °C). The treatment of mature-green fruit with 1-MCP for 1 h, and storage at 12 °C for up to 2 weeks prolonged the shelf-life about one week by delaying or reducing the respiration and ethylene production rates, skin colour changes, the loss of organic acids, and softening, with or without a further shelf-life period of 3 days at 20 °C. At 7 °C, 1-MCP also reduced mature-green fruit weight loss and shrivelling. Extending 1-MCP treatment periods at 20 °C to 6 or 12 h caused partial and uneven ripeness. Treating fruit in their post-climacteric stage of maturity had little effect on ripening compared with the mature-green stage. 1-MCP increased the respiration rate and/or the ethylene production in certain combinations of advanced harvest maturities and/or unfavourable storage temperatures. Recommendations for maintaining postharvest quality are harvesting at the mature-green stage, treatment with 1 μL L⁻¹ of 1-MCP for 1 h, and storage at 12 °C for up to 2 weeks.     

In vitro binding of bile acids by blueberries (Vaccinium spp.), plums (Prunus spp.), prunes (Prunus spp.), strawberries (Fragaria X ananassa), cherries (Malpighia punicifolia), cranberries (Vaccinium macrocarpon) and apples (Malus sylvestris)

The in vitro binding of bile acids by blueberries (Vaccinium spp.), plums (Prunus spp.), prunes (Prunus spp.), strawberries (Fragaria X ananassa), cherries (Malpighia punicifolia) cranberries (Vaccinium macrocarpon) and apples (Malus sylvestris) was determined using a mixture of bile acids secreted in human bile at a duodenal physiological pH of 6.3. Six treatments and two blank incubations were conducted to testing various fresh raw fruits on an equal dry matter basis. Considering cholestyramine (bile acid binding, cholesterol lowering drug) as 100% bound, the relative in vitro bile acid binding on dry matter (DM), total dietary fiber (TDF) and total polysaccharides (PCH) basis was for blueberries 7%, 47% and 25%; plums 6%, 53% and 50%; prunes 5%, 50% and 14%; strawberries 5%, 23% and 15%; cherries 5%, 37% and 5%; cranberries 4%, 12% and 7%; and apple 1%, 7% and 5%, respectively. Bile acid binding on DM basis for blueberries was significantly (P ? 0.05) higher than all the fruits tested. The bile acid binding for plums was similar to that for prunes and strawberries and significantly higher than cherries, cranberries and apples. Binding values for cherries and cranberries were significantly higher than those for apples. These results point to the relative health promoting potential of blueberries > plums = prunes = strawberries = cherries = cranberries > apples as indicated by their bile acid binding on DM basis. The variability in bile acid binding between the fruits tested maybe related to their phytonutrients (antioxidants, polyphenols, hydroxycinnamic acids, flavonoids, anthocyanins, flavonols, proanthocyanidins, catechins), structure, hydrophobicity of undigested fractions, anionic or cationic nature of the metabolites produced during digestion or their interaction with active binding sites. Inclusion of blueberries, plums, prunes, strawberries, cherries and cranberries in our daily diet as health promoting fruits should be encouraged. Animal studies are planned to validate in vitro bile acid binding of fruits observed herein to their potential of atherosclerosis amelioration (lipid and lipoprotein lowering) and cancer prevention (excretion of toxic metabolites).     

Polyphenolic profiles detected in the ripe berries of Vitis vinifera germplasm

Polyphenolic profiles in the berry samples of 344 European grape (Vitis vinifera) cultivars were evaluated for two consecutive years. These cultivars represent a diverse collection of V. vinifera germplasm maintained at the USDA-Agricultural Research Service Vitis Clonal Repository in Davis of California, USA. A total of 36 polyphenolic compounds, including 16 anthocyanins, 6 flavonols, 6 flavanols, 6 hydroxycinnamic acids and 2 hydroxybenzoic acids, were identified via HPLC–MS and quantified by HPLC–DAD. The mean contents for anthocyanins, flavanols, flavonols, hydroxycinnamic acids and hydroxybenzoic acids were 0.946 (coloured cultivars), 0.147, 0.043, 0.195 and 0.016 mg g⁻¹ FW, respectively. On average, wine grapes had higher concentrations than had table grapes for all of these compounds except hydroxycinnamic acids. Berry colours affected the total contents of anthocyanins, but not others. Positive correlations (0.151–0.535) were found among these groups of compounds. As expected, these groups of compounds were all negatively correlated with berry weight.     

Anthocyanin and glucosinolate occurrences in the roots of Chinese red radish (Raphanus sativus L.), and their stability to heat and pH

Roots of three unique Chinese radish cultivars were evaluated as potential sources for anthocyanin-type colourants or value-added products. These cultivars showed high variation in anthocyanins (63.77–160.74 mg/100 g FW). Seventeen pigments were tentatively identified by mass spectroscopy as pelargonidin-3-sophoroside-5-glucoside derivatives with multiple acylation of hydroxycinnamic acids. A bright colour (CIELab) of radish anthocyanins has been shown at a wide pH range, comparably stable at pH < 4.2. Those anthocyanins also showed a remarkable thermal stability, following a zero-order kinetics at pH 2.5 with half-lives of 14.5 or 8.7 h at 90 or 100 °C, respectively. Additionally, those cultivars varied in glucosinolate contents (59.69–163.91 mg/100 g FW), whereas their degradation was sensitive to pH and followed a first-order kinetics at pH 5.8 with half-lives of 11.44 or 7.05 h at 90 or100 °C, respectively. However, the stable pH ranges for anthocyanins and glucosinolates were different: pH < 4.2 and pH > 3.6, respectively. In a radish juice model (pH 5.8/2.5), thermal degradation of anthocyanins or glucosinolates was associated closely with media pH values. In conclusion, cultivar selection, and thermal and pH conditions during processing or storage should be taken into account for quality, stability, and health benefits of radish derived natural colourants or nutraceutical products.     

Optimization of frozen sour cherries vacuum drying process

The objective of this research was to optimize the vacuum-drying of frozen sour cherries in order to preserve health-beneficial phytochemicals, as well as textural characteristics. Investigated range of temperature was 46–74 °C and, of pressure, 17–583 mbar, in a new design of vacuum-dryer equipment. The total solids, a_w value, total phenolics, vitamin C, antioxidant activity, anthocyanin content, total colour change and firmness were used as quality indicators of dried sour cherry. Within the experimental range of studied variables, the optimum conditions of 54.03 °C and 148.16 mbar were established for vacuum drying of sour cherry. Separate validation experiments were conducted, under optimum conditions, to verify predictions and adequacy of the second-order polynomial models. Under these optimal conditions, the predicted amount of total phenolics was 744 mg CAE/100 dw, vitamin C 1.44 mg/100 g per dry weight (g dw), anthocyanin content 125 mg/100 g dw, IC₅₀ 3.23 mg/ml, total solids 70.72%, a_w value 0.646, total colour change 52.61 and firmness 3395.4 g. The investigated parameters had a significant effect on the quality of the dried sour cherries.     

Sweet cherry: Composition,postharvest preservation,processing and trends for its future use

BackgroundSweet cherries (Prunus avium L.) are a nutritious fruit which are rich in polyphenols and have high antioxidant potential. Most sweet cherries are consumed fresh and a small proportion of the total sweet cherries production is value added to make processed food products. Sweet cherries are highly perishable fruit with a short harvest season, therefore extensive preservation and processing methods have been developed for the extension of their shelf-life and distribution of their products.Scope and approachIn this review, the main physicochemical properties of sweet cherries, as well as bioactive components and their determination methods are described. The study emphasises the recent progress of postharvest technology, such as controlled/modified atmosphere storage, edible coatings, irradiation, and biological control agents, to maintain sweet cherries for the fresh market. Valorisations of second-grade sweet cherries, as well as trends for the diversification of cherry products for future studies are also discussed.Key findings and conclusionsSweet cherry fruit have a short harvest period and marketing window. The major loss in quality after harvest include moisture loss, softening, decay and stem browning. Without compromising their eating quality, the extension in fruit quality and shelf-life for sweet cherries is feasible by means of combination of good handling practice and applications of appropriate postharvest technology. With the drive of health-food sector, the potential of using second class cherries including cherry stems as a source of bioactive compound extraction is high, as cherry fruit is well-known for being rich in health-promoting components.     

Chemical stability of açai fruit (Euterpe oleracea Mart.) anthocyanins as influenced by naturally occurring and externally added polyphenolic cofactors in model systems

The influence of different classes of naturally occurring and externally added polyphenolic cofactors on the phytochemical and colour stability of anthocyanins in açai fruit (Euterpe oleracea) was investigated. Model systems were based on anthocyanin isolates from açai fruit, rich in cyanidin-3-rutinoside (311 ± 27 mg/l) and cyanidin-3-glucoside (208 ± 18 mg/l), and isolated groups of naturally occurring polyphenolic cofactors in açai fruit (phenolic acids, procyanidins, and flavone-C-glycosides, each adjusted to ∼50 mg/l). Anthocyanin degradation kinetics were assessed as a function of pH (3.0, 3.5, and 4.0) and storage temperature (5, 20 and 30 °C). During storage, anthocyanins experienced pH and temperature-dependent losses, and the half life cyanidin-3-rutinoside (t_1/2 = 2.67–210 days) was consistently longer than cyanidin-3-glucoside (t_1/2 = 1.13–144 days). The presence of flavone-C-glycosides induced significant hyperchromic shifts and enhanced anthocyanin stability at all pH and temperature combinations, while no significant effects were attributed to the presence of phenolic acids or procyanidins. Additional models using externally added cofactors from rooibos tea, also rich in flavone-C-glycosides, resulted in up to 45.5% higher anthocyanin colour and up to 40.7% increased anthocyanin stability compared to uncopigmented anthocyanin isolates and had similar copigmentation effects to a commercial rosemary-based colour enhancer. Results suggest flavone-C-glycosides offer potential for their use as colour enhancers and stabilizing agents in products rich in cyanidin glycosides, particularly açai fruit-containing foods, juice blends, and beverages.     

Polyphenolic composition and content in the ripe berries of wild Vitis species

To explore wild genetic resources for improving fruit and processing quality of cultivated grape cultivars, the polyphenolic composition and content in the ripe berries of 147 grape accessions from 16 Vitis species for two consecutive years were characterised. A total of 48 polyphenolic compounds, including 28 anthocyanins, 6 flavonols, 6 flavanols, 6 hydroxycinnamic derivatives, and 2 hydroxybenzoic acids, were identified via HPLC-MS and quantified by HPLC-DAD. These wild grape species had unique presence of abundant di-glucoside derivatives of anthocyanins. In addition, anthocyanins in most wild species were predominantly nonacylated. The mean contents for anthocyanins, flavanols, flavonols, hydroxycinnamic derivatives, and hydroxybenzoic acids were 9.610, 0.769, 0.093, 0.441 and 0.027 mg g⁻¹ FW, respectively. They were about 2 to 10 folds higher than their respective counterparts in the most widely cultivated grape species Vitis vinifera. As expected, most of these groups of compounds were correlated negatively with berry weight, but positively with the content of total soluble solids.     

Different postharvest strategies to preserve broccoli quality during storage and shelf life: Controlled atmosphere and 1-MCP

Broccoli (Brassica oleracea var. italica) is a vegetable that requires the application of postharvest techniques to extend its marketability. Controlled atmosphere and 1-MCP treatments are most used to extend the shelf life of broccoli and reduce post-harvest deterioration. The aim of this study was to evaluate the visual, physicochemical and functional changes of broccoli head samples stored at 1–2 °C and 85–90% relative humidity (RH) in air (Control samples), under controlled atmospheres (10% O₂ and 5% CO₂) (CA samples) and treated with 1-MCP (0.6 μL/L). After storage all samples were maintained at 20 °C for 2 and 4 days, in order to assess their shelf life. The most suitable postharvest treatment to extend broccoli quality during storage and shelf life, in terms of maintaining the visual quality and reducing loss of health-promoting compounds, was achieved by storage under controlled atmosphere conditions. The use of 1-MCP reduced the loss of green colour and chlorophyll pigments, but only during cold storage not during shelf life at 20 °C.     

The impact of oxygen exposure before and after bottling on the polyphenolic composition of red wines

The impact of moderate oxygen exposure after bottling on wine phenolic composition and colour properties has been investigated on four Grenache red wines showing high and low phenolic contents, obtained by flash release (FR) and traditional soaking (Trad), respectively, and processed with (Mox, 4.6 mg l⁻¹ O₂) or without (noMox) micro-oxygenation. Four oxygen transfer rate (OTR) conditions (0.8, 1.9, 8.0, and 11.9 μl oxygen/bottle/day) were ensured by using synthetic closures with controlled oxygen permeability and storage under controlled atmosphere. Wine phenolic composition and colour were monitored by triplicate analysis of bottles sampled at bottling (T0) and after 5 and 10 months of ageing. Phenolic composition was determined by reverse-phase HPLC-DAD–MS analysis, performed directly on the wines and after phloroglucinolysis for proanthocyanidins. Colour was evaluated by UV–visible spectrophotometry and tristimulus colorimetry. At T0, FR wines contained larger amounts of catechins, proanthocyanidins and hydroxycinnamic acids and slightly lower amounts of anthocyanins than the Trad wines while the Mox wines showed higher levels of some derived pigments, especially carboxypyranoanthocyanins, resulting from reactions of anthocyanins with pyruvate. During ageing, a progressive decrease of proanthocyanidins and hydroxycinnamic acid concentrations was observed, independently of OTR. In contrast, the loss of free SO₂, flavan-3-ol monomers and the conversion rate of anthocyanins to new pigments, especially into sulphite bleaching resistant pigments, increased with OTR levels. Among derived pigments, carboxypyranoanthocyanins levels increased both with micro-oxygenation and with OTR and can be considered as oxidation markers while flavan-3-ol–anthocyanin adducts were formed in larger amounts with lower oxygen exposure.     

Fruit quality and physiological responses of litchi cultivar McLean's Red to 1-methylcyclopropene pre-treatment and controlled atmosphere storage conditions

The effect of 1-MCP pre-treatment and two different controlled atmosphere storage conditions (CA-1, 17% O₂ + 6% CO₂; CA-2, 7% O₂ + 3% CO₂) on fruit quality parameters and physiological changes with respect to pericarp browning in ‘McLean's Red’ litchi were investigated. Fruits were pre-treated with 1-MCP (500 nl/l) and held at CA-1 or CA-2 for 21 d at 2 °C and at 90% RH. Stand-alone CA-1 or stand-alone CA-2 and the commercially adopted sulphur dioxide (SO₂) treatment were included in this study for comparison. Of the five treatments 1-MCP + CA-1 was most effective in preventing browning, loss of red colour (colour value a*) of the pericarp, ascorbic acid content; and retaining acceptable SSC/TA and taste. Fruit from 1-MCP + CA-1 showed higher overall acceptance after 21 d storage without any off-flavour according to the sensory panel data.1-MCP + CA-1 reduced the polyphenol oxidase (PPO) and peroxidase (POD) activity, retained membrane integrity and anthocyanin content during storage. Although SO₂ treatment prevents browning it showed negative effects on SSC/TA, taste and membrane integrity. Stand-alone CA-2 condition indicated higher pericarp browning, PPO, POD activity and loss of membrane integrity. Therefore, 1-MCP pre-treatment and CA-1 retains overall fruit quality for up to 21 d.     

Fatty acid and sugar composition of avocado,cv. Hass,in response to treatment with an ethylene scavenger or 1-methylcyclopropene to extend storage life

This study reports on the effect of 1-methylcyclopropene (1-MCP) and a newly developed palladium (Pd)-promoted ethylene scavenger (e + ® Ethylene Remover) on changes in firmness, colour, fatty acids and sugar content of early and late season avocado (Persea americana Mill.), cv. Hass, during storage at 5 °C and subsequent ripening at 20 °C. The e + ® Ethylene Remover effectively delayed ripening of avocado stored at 5 °C. 1-MCP was more effective at inhibiting ripening, but, in contrast to e + ® Ethylene Remover, it impaired subsequent ripening. Fatty acid profile of late season fruit remained unchanged in response to treatments or storage time, whilst that of early season fruit was slightly, yet significantly, different according to treatments and storage time. Substantial amounts of perseitol were found in all fruit. In contrast, mannoheptulose was only present at high concentration in early season fruit whilst it was quasi-absent in late season fruit. Where ripening was inhibited in response to 1-MCP treatment, significantly more mannoheptulose and better maintenance of perseitol was found vs. controls. Similarly, but to a lesser extent and concomitant with trends in firmness retention and colour changes, e + ® Ethylene Remover led to greater maintenance of mannoheptulose and perseitol than that of controls. This is the first piece of research comparing effects of ethylene removal vs. ethylene action blocking on physical and biochemical changes in avocado cv. Hass and supports the view that C7 sugar metabolism could be an important feature of the avocado fruit-ripening process.