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1.
There is a need to develop alternative harvest indexes for black skinned plums. The aim of this research was to analyze and compare the most commonly used indexes for deciding the harvest date for Japanese plum, and evaluate the effectiveness of new approaches for studying maturation. The ripening process was monitored on-tree and during postharvest in a non-destructive way, through the absorbance of chlorophyll (IAD), the compression strength of the intact fruit, and the traditional parameters associated with ripening. Fruit were harvested at commercial ripeness and “tree-ripe”, and were stored for 10 d at 22 °C and 75-80% RH. The IAD decreased during the last phase of development of the fruit on-tree, and it was related to the common indexes used for plums. ‘Angeleno’ showed a decrease of the IAD 24% lower than that observed for ‘Autumn beaut’. The IAD versus time showed the highest coefficients of determination when compared with the soluble solids concentration (SSC), flesh firmness, hue (H°) and chroma (C*) of the skin. The compression strength of the intact fruit was associated with flesh firmness, and to a lesser extent with the SSC for ‘Angeleno’, whereas for ‘Autumn beaut’ higher correlations for both the SSC and flesh firmness were observed. The C* of the skin on ‘Autumn beaut’ showed an erratic change during ripening; by contrast, for ‘Angeleno’, this index showed a clear trend. During postharvest it was observed that for ‘Angeleno’ fruit picked at commercial ripeness, the rate of change of the IAD was practically the same as observed on-tree, while for ‘Autumn beaut’ the rates of change on-tree and at postharvest were 0.075 IAD d−1 and 0.024 IAD d−1, respectively. For the “tree-ripe” fruit, the rate of change was practically the same for both cultivars. Similar trends were observed for the compression strength.  相似文献   

2.
Physical and chemical changes in sapote mamey (Pouteria sapota (Jacq.) H.E. Moore and Stearn) fruit during ripening and storage at various temperatures were evaluated. Ripening was associated with flesh softening, an increase in soluble solids content (SSC), and a change in flesh color from yellow or pale pink to a dark pink or red. No changes in fruit skin color or in flesh acidity were observed as ripening progressed. Ripe fruit had 30% or higher SSC, orange or red flesh (hue angle=52; chroma=45; L=60), acidity of 6–8 mM H+, and flesh firmness (compression force) ≤50 N. Flesh turned brown (L* value declined) in overripe fruit. Fruit held at 27, 25, or 20°C ripened in 3.5, 5 or 7 days after harvest, respectively. Fruit kept at 10°C showed minor changes in color and firmness and a slow rate of SSC increase. Fruit stored at 10 or 15°C and then ripened at 20°C had portions of the flesh with a much higher firmness and poorer development of red color compared to other parts of the fruit. This uneven ripening was probably a result of chilling injury. The number of fruit with injury was higher at 10°C than at 15°C, and increased with storage time. The rates of fruit weight loss relative to the initial fruit weight were 0.58, 0.98 and 1.83% d−1 at 10, 20 and 27°C, respectively.  相似文献   

3.
A two year research was carried out on a table grape vineyard, cv. Italia, to evaluate the effectiveness of pre- and post-veraison calcium applications for controlling postharvest table grape rots and maintaining high fruit quality during cold storage. Two calcium application timings (from fruit set to veraison and from veraison to harvest) were compared to an untreated control. Clusters were sprayed with calcium chloride as Ca EDTA 44%. After each calcium application, bunch samples were collected and Ca2+ concentration was measured in berry compartments (skin, flesh and seeds). The main mechanical and chemical characteristics were measured on bunch samples at harvesting and during storage. In addition, the incidence of Botrytis cinerea rots, computed as McKinney index, was evaluated in field on natural inoculum and after harvesting on bunches artificially inoculated and maintained at room temperature. The highest Ca2+ concentrations were detected in skin tissues and after pre-veraison applications. Calcium accumulation in skin and flesh tissues stopped after veraison, whereas it continued up to ripening in seeds since the axial flow, differently from the peripheral, remains functional. In both years, calcium applications to bunches were effective both in maintaining postharvest fruit quality, as shown by flesh firmness and berry breaking force, and in reducing B. cinerea rots during storage. The applications were particularly efficacious if carried out between fruit set and veraison when stomata are functional and the re-translocation of calcium not directly absorbed by the bunches may occur via xylem transport.  相似文献   

4.
The effect of treatment with diphenylamine (DPA) and duration of postharvest storage of whole apple fruit on the responses of fresh-cut apple slices to elevated CO2 storage atmospheres has been investigated. On the day of harvest, ‘McIntosh’, ‘Empire’ and ‘Delicious’ apples were untreated or dipped in DPA, and were held at 0.5 °C overnight or for 6 weeks before slicing. Slices were then stored at 0, 15, 30, 45 or 60% CO2 in 1% O2 (balance N2), atmospheres. Color, firmness and accumulation of acetaldehyde, ethanol and ethyl acetate of the slices were measured. Generally slices were lighter (higher L* values) when stored in elevated CO2 atmospheres, but atmosphere and DPA effects varied by cultivar and were affected by pre-slice storage time. Slices prepared from stored fruit were softer compared with slices prepared at harvest. Slice firmness was not affected consistently by CO2 or DPA concentration, whether they were prepared at harvest or after storage. The effects of increasing CO2 concentration on acetaldehyde and ethanol accumulations were variable, being affected by cultivar and storage period. DPA treatment did not affect acetaldehyde accumulation of any cultivar, or ethanol accumulation of slices prepared from fruit at harvest. However, DPA-treated ‘Empire’ and ‘Delicious’ apples stored before slicing accumulated less ethanol compared with untreated fruit. Storage of apples before processing increased the accumulation of fermentation volatile compounds by cut apples under storage atmosphere conditions.  相似文献   

5.
Treatment with UV-C of tomato fruit on the vine was conducted using a mobile unit that was designed to be conveyed between the rows of tomato plants in a commercial glasshouse. Trusses of fruit both at the ripe and mature green phase were treated with UV-C doses of 3 and 8 kJ/m2. Ripe fruit were picked 8 h after treatment and kept at room temperature for up to 16 d during which colour development and texture were monitored and compared to untreated controls. Mature green fruit treated on the vine with UV-C doses of 3 or 8 kJ/m2 showed only a slight loss in green pigmentation in contrast to the tomato colour index (TCI) of control fruit which increased sharply 5 d after treatment. The TCI of ripe fruit treated with UV-C at a dose of 8 kJ/m2 showed a lag of 10 d before increasing to a final value comparable to that of untreated fruit. Fruit treated with a dose of 3 kJ/m2 did not display a lag but the increase in TCI occurred at a lower rate than for the controls. Firmness remained higher in fruit treated with the highest UV-C dose compared to fruit treated with the lower UV-C dose and controls. Fruit covered with UV impermeable film on the same plants as those that had received a UV-C dose of 3 kJ/m2 had become ripe by day 6 in a manner similar to that of the controls. By contrast, fruit from trusses adjacent to those that had been treated with a UV-C dose of 8 kJ/m2 remained green over the same period of time. Ripe fruit treated as described above were inoculated with spores of Penicillium digitatum after UV-C treatment and their firmness monitored over 12 d. A dose response effect was found with fruit treated at the highest dose remaining firmer than those treated at the lower dose and the controls.  相似文献   

6.
Peel yellowing is a major postharvest problem of lime fruit. Research was conducted to control peel yellowing by UV-B irradiation. Mature green lime fruit were irradiated with UV-B doses at 0 (control), 8.8, and 13.2 kJ m?2 and then stored at 25 °C in darkness. UV-B treatment at 8.8 kJ m?2 efficiently delayed the decrease of chlorophyll content. A high level of chlorophyllide a accumulated in mature green fruit and then gradually decreased with the progress of peel yellowing. The chlorophyllide a level was higher in 8.8 kJ m?2 UV-B-treated fruit than it was in the controls. The pheophorbide a level declined in lime fruit treated with 8.8 kJ m?2 UV-B, especially during the development of yellowing. In addition, the pheophytin a level increased by 8.8 kJ m?2 UV-B treatment at the late period of storage. We concluded that UV-B treatment effectively suppressed chlorophyll degradation in mature green lime during storage, which suggests that UV-B irradiation is a usable method for prolonging the postharvest life of lime fruit.  相似文献   

7.
The effects of 2-alkyl derivatives of 2-cyclopropene-1-carboxylic acid ethyl ester (CPE) with various lengths of alkyl side chains were examined on ethylene production and flesh softening of ‘Taishuu’ and ‘Fuyu’ persimmon (Diospyros kaki L.) fruit. When the ‘Taishuu’ fruit were treated with gaseous forms of the CPEs with short alkyl chains, the increased ethylene production and decreased flesh firmness of fruit were not inhibited. However, ripening parameters were inhibited by the CPEs with long alkyl chains in proportion to the carbon number. Decyl CPE (DCPE) is relatively stable and sprayable and inhibited postharvest flesh softening of ‘Fuyu’ fruit when sprayed before harvest. Thus, DCPE appears to be a valuable agent for delaying flesh softening of persimmon fruit.  相似文献   

8.
The objective of this work was to preserve the postharvest quality of litchi cv Brewster by the application of Lactobacillus plantarum. A suspension of 1 × 109 CFU/mL of the bacteria was sprayed on ripe litchis and then stored at 10 °C with 75% of relative humidity. Treated fruit exhibited a significantly higher Gram positive bacteria growth on the rind (4–5 log CFU/g) than that detected in control fruit (2.5–3.75 log CFU/g). This result was corroborated by observing a high population of lactobacilli in scanning electron micrographs and by measurement of the content of lactic acid produced. Treated fruit displayed significantly (α  0.05) reduced color losses as indicated by the higher L* and C* values in comparison with the untreated ones. Additionally, cyanidin-3-rutinoside and total anthocyanin contents supported the measured color retention, since the pericarp of fruit treated with Lb. plantarum showed a significantly higher concentration of pigments than those used as control. In addition, a high concentration of phenolic compounds was found in the rind of treated fruit.  相似文献   

9.
The mechanical harvesting of Manzanilla fruit destined for Spanish-style green table olives has never been developed on an industrial scale because of the brown spots formed on the bruised areas during olive transportation from the groves to the olive factories. In this study, the use of several inert atmospheres to preserve mechanically harvested olives was investigated. Nitrogen, argon and nitrogen spiked with SO2 (0.01–0.05%) prevented the formation of brown spots on the bruised areas for at least 6 h but the browning reactions rapidly progressed after the inert atmosphere was released. Olives were also immersed in several chemical solutions (0.5% ascorbic acid, 0.3% NaOH, 0.05% SO2, and 1% glycerol) before and after the postharvest storage in nitrogen with the aim of reducing oxygen diffusion into the fruit. Only the use of glycerol as a coating layer before the nitrogen atmosphere showed slightly good results. Moreover, it has been demonstrated that the browning reactions in bruised olives were developed due to the oxidation of oleuropein without the requirement of any previous hydrolysis reactions of this polyphenol. The decrease in oleuropein and increase in darkening of the bruised areas of olives preserved in nitrogen and re-exposed to air was also caused by enzymatic reactions.  相似文献   

10.
Canonical discriminant analysis (CDA) was used to identify the best method to discriminate between maturity and ripening stages, assessed in terms of dry matter content, firmness, color (peel and flesh), total soluble solids content attributes, before and during ‘Keitt’ mango ripening at 20 °C. Dry matter content was determined by hot-air oven and microwave oven methods. Fruit firmness was determined non-destructively by hand squeezing, with a durometer, using acoustic resonance and low-mass elastic impact methods (AWETA), as well as destructively by the penetrometer. Peel and flesh color were expressed as L*, a*, b*, h0 and C* values. Total soluble solids content was analyzed from filtered juice from whole fruit tissue and from unfiltered juice squeezed out by hand. Canonical discriminant analysis indicated that the durometer and the penetrometer were better methods to assess firmness than hand firmness, acoustic resonance or impact methods. The best color attributes to follow changes during early stage of ‘Keitt’ mango ripening were a* and b* values of the flesh, whereas b* value of the peel was considered better during later stages of ripening. Results of total soluble solids content in filtered juice from whole fruit tissue were less variable compared to unfiltered juice squeezed out by hand. Dry matter content was better assessed by drying the sample in a microwave oven than in a hot-air oven. A combined CDA including the best methods to assess each ripening attribute, as well as titratable acidity, showed that the best tools to assess changes in fruit during ripening were the penetrometer, followed by flesh a* value and total soluble solids content (from filtered juice from whole fruit).  相似文献   

11.
A strain of Bacillus amyloliquefaciens HF-01, isolated from citrus fruit surfaces, was screened for in vitro antagonism toward Penicillium digitatum and identified, based on Biolog identification and phylogenetic analysis of 16S rDNA sequences. The isolate was further evaluated alone, or in combination with tea saponin (TS) on artificially inoculated ‘Wuzishatangju’ mandarin fruit. The results showed that the isolate performed significantly better than the water control in reducing the incidence of green and blue mold and sour rot, but was not as effective as the fungicide treatment. Biocontrol activity of B. amyloliquefaciens HF-01 was significantly improved by addition of TS, which might influence the formation of a bacterial biofilm and stimulate the antagonist population in wounds. The treatment comprising HF-01 combined with 50 μg mL?1 TS was as effective as the fungicide treatment, which gave more than 90% control of green and blue mold and sour rot. B. amyloliquefaciens HF-01 alone or in combination with a low dosage of TS significantly reduced postharvest decay without impairing any of the other fruit quality parameters. The combination of B. amyloliquefaciens HF-01 and TS could be an alternative to synthetic fungicides for the control of citrus postharvest diseases.  相似文献   

12.
The objective of this study was to evaluate the use of an ethanol vapor release pad and a saprophytic yeast Cryptococcus infirmo-miniatum (CIM) to reduce decay and maintain postharvest quality of intact or fresh-cut sweet cherries (Prunus avium) cv. Lapins and Bing. Intact or fresh-cut fruit were packed in perforated clamshells (capacity 454 g) and stored at 1, 10 or 20 °C for up to 21, 14 and 8 d, respectively. For ethanol treatment, a pad made with silica gel powder containing 10 g ethanol and covered with perforated film, which allows ethanol vapor to diffuse gradually, was attached to the upper lid of the clamshells. Ethanol treatment caused accumulation of ethanol in the packaging headspace, about 10 μL L−1 with little change within 14 d at 1 °C, 23 μL L−1 at d 1 and decreased to 15 μL L−1 at d 10 at 10 °C, and 26 μL L−1 at d 1 and decreased to 13 μL L−1 at d 3 at 20 °C. Ethanol content in fruit was less than 9 mg kg−1 in all the control fruit, and increased to 16, 34 and 43 mg kg−1 in ethanol-treated fruit at 1, 10 and 20 °C, respectively. Nonetheless, a sensory taste panel did not perceive any flavor difference from the ethanol treatment. The ethanol treatment retarded softening, darkening, and acid decrease in fruit as well as discoloration of the stems, and extended shelf-life of intact cherries. Ethanol reduced brown rot (Monilinia fructicola) in fresh-cut cherries stored at 20 °C, but not at 1 and 10 °C. A pre-packaging dip in CIM completely controlled brown rot in inoculated fresh-cut cherries stored at 1 °C, and in naturally infected cherries at 20 °C.  相似文献   

13.
Skin background colour is an important quality aspect in the grading of ‘Jonagold’ apples, with consumers usually preferring fruit with a green background colour. However, apple handlers are usually faced with large fruit-to-fruit variability of background colour within a population of fruit. In this study, a stochastic modelling approach was used to describe how the initial fruit-to-fruit variability in the background colour of ‘Jonagold’ apples present at harvest, propagates throughout the postharvest chain. Two hundred and twenty ‘Jonagold’ apple fruit were harvested and stored at 1 °C or 4 °C, under different controlled atmosphere (CA) conditions for 6 months, followed by 2 weeks exposure to shelf-life conditions, during which the background colour and ethylene production of the individual fruit were measured. A kinetic model was developed to describe the postharvest loss of skin greenness, by assuming that the loss was principally due to chlorophyll breakdown, the rate of which was dependent on the endogenous ethylene concentration. Stochastic model parameters were identified, and by treating these parameters as fruit-specific, the model could account for more than 95% of the variability of the data. By treating the stochastic model parameters as random factors, the Monte Carlo method was used to model and describe the propagation of the fruit-to-fruit variability of the background colour within a population of fruit. The model developed in this study might allow better management of variability in quality along the postharvest chain, by predicting how the initial fruit-to-fruit variability within a batch of apples will propagate throughout the postharvest chain, as a function of storage and shelf-life conditions.  相似文献   

14.
Methyl jasmonate (MeJA) can act as an activator of defense responses in plants against pathogenic infection. However, the mechanisms involved in the postharvest induction of resistance by MeJA in fruit are largely unknown. Thus, we investigated the effect of a postharvest MeJA treatment on disease resistance against Penicillium citrinum infection in Chinese bayberries and the possible mechanisms. The results indicated that treatment with 10 μmol L−1 of MeJA significantly inhibited green mould rot caused by P. citrinum, with the decay incidence being 66.2% lower than that of the control fruit after storage at 1 °C for 8 d. Moreover, it is clear that MeJA triggers a priming mechanism in Chinese bayberries, since only the MeJA-treated fruit showed an enhanced capacity to augment defense responses upon challenge with the pathogen. These augmented responses included an H2O2 burst, enhanced protein levels of phenylalanine ammonia-lyase and chitinase, and accumulation of phenolic compounds, lignin and phytoalexin. Therefore, our results suggest that a postharvest MeJA treatment induces disease resistance against P. citrinum in Chinese bayberries by priming of defense responses.  相似文献   

15.
In this work, Metschnikowia pulcherrima Disva 267, Wickerhamomyces anomalus Disva 2, and Saccharomyces cerevisiae Disva 599 yeast strains were evaluated for their biocontrol activity on postharvest decay brown rot, mainly caused by Monilinia laxa on sweet cherries, using three increasing concentrations (106, 107 and 108 CFU/mL). M. pulcherrima significantly reduced brown rot incidence, severity and McKinney index at all three concentrations, W. anomalus was effective at the concentration of 107 CFU/mL, and S. cerevisiae reduced brown rot only at 108 CFU/mL. M. pulcherrima and W. anomalus survived on the surface of sweet cherries during 2 weeks cold storage. When the three yeasts were sprayed on the canopy of sweet cherry trees at 107 CFU/mL, M. pulcherrima and W. anomalus showed good survival and colonization. In contrast, under the same conditions, S. cerevisiae strain did not survive. None of the yeasts produced phytotoxic substances, both on intact and on wound-inoculated fruit. Therefore, M. pulcherrima Disva 267 and W. anomalus Disva 2 could be promising biocontrol agents, able to survive in field and storage environments, providing a clear decrease in postharvest decay. However, further investigations with large scale trials are needed to lead to a possible formulation and commercial use.  相似文献   

16.
Longkong (Aglaia dookkoo Griff.) fruit rapidly loses its yellow skin color and turns brown after harvest. We aimed to elucidate the postharvest physiology and browning mechanism of longkong fruit stored at a 70–85% RH and at room temperature (25 °C). The respiration rate slightly decreased with progressive fruit browning, while ethylene production was dramatically increased. Preliminary experiments showed that ethylene treatment markedly increased peel browning, suggesting that this is induced by ethylene. The peel L-value continuously decreased during storage, in relation to the severity of peel browning. The peel surface morphological data indicated that the ultrastructure of longkong peel collapsed after harvest, especially around brown areas. The total phenolic content of peel tissue rapidly increased, concomitant with rapid increases in phenylalanine ammonia lyase (PAL) activity and browning score on day 2. Tissue from the lower part of the fruit had higher total phenolic contents, as well as polyphenol oxidase (PPO) and PAL activities, compared to the top and middle parts of the fruit; however, peroxidase (POD) activity slightly changed during storage, possibly independent of phenol oxidation. The browning of longkong peel was not associated with changes in soluble solids contents, titratable acidity or ascorbic acid levels.  相似文献   

17.
Previous studies have demonstrated a relationship between Md-ACS1 allelotype and apple fruit softening at ambient temperatures. The present study was undertaken to further examine the influence of this allelotype (-1/1, -1/2 or -2/2) and its interaction with harvest season (early or late) on changes in internal ethylene concentrations (IEC) and fruit softening during cold air storage. This was carried out by describing natural differences found among old apple cultivars/species and modern commercial cultivars. For late maturing cultivars, Md-ACS1-1/1 was firmer at harvest than Md-ACS1-2/2 with the heterozygote intermediate. However harvest firmness showed no differences among for the early season Md-ACS1 allelotypes. The Md-ACS1-2/2 allelotype had a slower rate of postharvest IEC increase and flesh softening compared with Md-ACS1-1/1 and -1/2 allelotypes, and late maturing cultivars had a slower rate of fruit softening than early maturing cultivars, which was independent of postharvest IEC. All three late season allelotypes and early season Md-ACS1-2/2 were firmer after storage than early season Md-ACS1-1/1 and -1/2 allelotypes, reflecting differences in both harvest firmness and softening rates. While cultivar variation in final firmness could be explained partially through Md-ACS1-mediated postharvest ethylene increases and subsequent softening, much more variation was accounted for by their differences in harvest firmness. These results are discussed in relation to strategies for breeding cultivars with superior flesh textures that are maintained during storage.  相似文献   

18.
In this work the gas diffusion of ‘Golden’ papaya fruit (Carica papaya L.) was evaluated as a function of different maturity stages, by using a photoacoustic spectrometer. The maturity stages were characterized by the anatomical changes, membrane integrity, pulp firmness, and skin color. Microstructural analysis was performed by means of light and scanning electron microscopy. A significant decrease in the diffusion rate with ripening was observed. Under the experimental conditions it was found that fruit in maturity stage 0 (less mature) had turgid, regular shape parenchyma cells, and relatively little intercellular spaces. However, fruit in maturation stage 5 (more mature) showed separation of cell walls and pectic substance accumulation into the intercellular spaces. The skin color showed a reduction in hue angle values and an increase in chromaticity parameters a* and b*, characterizing the loss of green color during ripening. A loss of firmness of the pulp was also observed during fruit ripening.  相似文献   

19.
Side cracking and ostiole-end splitting skin damage affected decay development and the percentage of sound fruit during fresh fig (Ficus carica L.) postharvest handling and marketing. Modification of current grading standard tolerances according to cultivar is suggested to protect the consumers and improve marketable yield. The type and degree of skin damage varied among cultivars. For ‘Brown Turkey’, ‘Kadota’ and ‘Sierra’, slight skin-damage prior to cold storage increased decay and reduced postharvest life. In contrast, the postharvest life of ‘Black Mission’ fig was not significantly affected by a slight degree of skin damage prior to cold storage. Furthermore, postharvest decay incidence was associated with the degree of side cracking and ostiole-end splitting at harvest. Because fruit skin side cracking and ostiole-end splitting occur during fruit growth and development, prevention by regulated deficit irrigation (RDI) with 55% ETc was studied for two years. In both seasons, fruit quality attributes were not affected by RDI, except for ‘Brown Turkey’, where size decreased by 21% during one season. RDI significantly reduced fruit skin side cracking and ostiole-end splitting in ‘Brown Turkey’ and skin side cracking in ‘Sierra’, increasing marketable fruit by 50% in ‘Brown Turkey’ and 18% in ‘Sierra’.  相似文献   

20.
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