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P. Perkins-Veazie, J.R. Clark, D.J. Huber, and E.A. Baldwin

Fruit were harvested from an erect, thornless blackberry (Rubus L. subgenus Rubus Watson, `Navaho' to study ripening changes. Soluble solids content increased between the red (unripe) and dull-black (overripe) stages of ripening while titratable acidity decreased sharply between the mottled and shiny-black ripeness stages. Anthocyanin content increased sharply between the mottled and shiny-black stages. Firmness of drupelet and receptacle tissues decreased between the mottled and shiny-black stages of ripeness. In whole blackberries, total uronic acids decreased, and water soluble uronic acids increased between the green-red and shiny-black ripeness stages. Volatile production paralleled ripening changes, and was highest in dull-black fruit, with alcohols and aldehydes predominating. Respiration of intact fruit maintained in water decreased between the green and red ripeness stages and increased at the mottled (part-black) and black ripeness stages. Ethylene production remained below 10 nmol·kg-1·h-1 until the dull-black (overripe) stage of maturity. Free 1-aminocyclopropane-1-carboxylic acid (ACC) and ACC oxidase did not increase in berries until the shiny-black stage, corresponding with the onset of detectable ethylene production. ACC oxidase activity decreased in the drupelet tissue (0.5 to 0.01 μmol·kg-1·h-1) and increased in the receptacle tissue (2 to 3.8 μmol·kg-1·h-1) as fruit changed from red to dull black. These results indicate that ripening in blackberries may be initiated in the receptacle tissue. Ripening in blackberries is likely independent of ethylene, but ethylene may regulate berry detachment from pedicels, thus controlling timing of fruit harvests.

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Christopher B. Watkins and Jacqueline F. Nock

The effects of temperature during 1-MCP treatment, and the effects of delays of up to 8 d after harvest before treatment, have been investigated using `Cortland', `Delicious', `Jonagold', and `Empire' (normal and late harvest) apple [(Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] cultivars stored in air for 2 and 4 months and in controlled atmosphere (CA) storage for 4 and 8 months. Fruit were treated with 1 μL·L–1 1-MCP for 24 hours on the day of harvest (warm) or after 1, 2, 3, 4, 6, or 8 days at cold storage temperatures. CA storage was established by day 10. Little effect of temperature during treatment (warm fruit on the day of harvest compared with cold fruit after 24 hours of cooling) was detected. Major interactions among cultivars, handling protocols before 1-MCP treatment, storage type and length of storage were observed. Delays of up to 8 days before 1-MCP treatment either did not affect efficacy of treatment, or markedly reduced it, depending on cultivar, storage type and length of storage. The results indicate that, depending on cultivar, the importance of minimizing the treatment delay increases as storage periods increase.

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R. Massantini, L. Lanzarotta, R. Botondi, and F. Mencarelli

Brushing of `Hayward' kiwifruit [Actinidia deliciosa (A. Chev.) C.F. Liang et A. R. Ferguson var. deliciosa] to remove trichomes reduced their marketable life. Fruit were brushed with polypropylene brushes having bristles of 0.60, 0.50, 0.30, and 0.25 mm in diameter. The two smallest-diameter bristles removed about 0.1 g of trichomes per fruit. The larger diameter bristles removed 12% more material, including some surface tissue particles. Brushing accelerated ripening during subsequent storage of fruit for 4 days at 4C as indicated by increases in ethylene production and soluble solid concentration and a decrease in firmness. The larger the bristle diameter, the greater the acceleration of ripening. The largest diameter did not accelerate ripening as much as 0.50-mm bristles due to the lower resistance to bending (0.85 N and 2 N for 0.60- and 0.50-mm bristles, respectively) and their greater length. Small surface wounds, visible under the microscope, may have caused the higher ethylene evolution and the consequent ripening response.

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Paul T. Dauny and Daryl C. Joyce

Better maintenance of firmness and suppression of ethylene production in 'Queen Cox' and 'Bramley' apple [Malus ×sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] fruit was achieved by prestorage applications of 1-MCP. 1-MCP concentration, exposure time and exposure temperature ranges of 0.1 to 10.0 μL·L-1 1-MCP, 6 to 48 h, and 0 to 20 °C, respectively, were effective on fruit subsequently stored for 2 ('Cox') and 3 ('Bramley') months in air at 3 to 4 °C. However, 1-MCP had little effect on either firmness or ethylene production after 4 ('Cox') or 6 ('Bramley') months storage. Nonetheless, 1-MCP treated 'Bramley' fruit had reduced rot and superficial scald incidences compared with untreated control fruit. Chemical name used: 1-methylcyclopropene (1-MCP).

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R.L. Jackman, A.G. Marangoni, and D.W. Stanley

Flat-plate compression, constant area compression, and puncture tests were examined for their sensitivity in differentiating the firmness of previously chilled (6C, 85% RH, 15 days) and nonchilled mature-green tomato (Lycopersicon esculentum Mill cv. Caruso) fruit during 10 days of ripening at 22C. Firmness, as measured by each of the three methods, progressively decreased (P < 0.001) with ripening. Previously chilled tomatoes were initially softer (P < 0.01) than nonchilled tomatoes, as measured by puncture of whole fruit and constant area compression of pericarp tissue sections, but not by flat-plate compression of whole fruit. Flat-plate compression was therefore found to be a relatively insensitive method by which to measure differences in tomato firmness that are characteristic of slightly chilling-injured fruit.

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Muharrem Ergun, Donald J. Huber, Jiwon Jeong, and Jerry A. Bartz

The purpose of the present study was to investigate the role of ethylene action, via use of the ethylene antagonist 1-methylcyclopropene (1-MCP), on the senescence and quality of fresh-cut ripe papaya (Carica papaya L. `Sunrise Solo') fruit. Ripe papaya fruit were treated with 2.5 μL·L-1 1-MCP and immediately processed into fresh-cut slices or left intact. At 2-day intervals over 10 days at 5 °C, continuously stored slices were monitored for ethylene production, firmness, electrolyte leakage, color, sensory changes, and pathogen incidence. Slices freshly prepared from intact fruit stored under identical conditions were measured similarly. Ethylene production did not differ significantly between the treatments, although production rates were slightly but consistently higher in slices from intact control compared with intact 1-MCP-treated fruit. Mesocarp firmness of continuously stored slices and slices from fruit stored intact was significantly retained by 1-MCP. Firmness of continuously stored slices from 1-MCP-treated fruit declined 50% compared with 75% for control slices. Firmness of fresh-cut slices prepared from intact control and 1-MCP-treated fruit at each sampling interval declined 26% and 15%, respectively. Electrolyte leakage remained low and changed little in slices freshly prepared from fruit stored intact. Leakage from continuously stored papaya slices increased after 4 days, and after 6 days controls increased significantly compared with stored slices derived from papaya fruit initially treated with the ethylene antagonist. The flesh color of continuously stored slices or slices prepared from fruit stored intact was influenced by 1-MCP only during the later periods of storage. Microbial counts in stored slices or slices prepared at each sampling were generally unaffected by 1-MCP. Informal sensory analysis indicated that the edible shelf life was 6 days in stored slices from 1-MCP-treated fruit compared with 2 to 3 days for stored slices from control fruit.

Open access

Jingjing Kou, Zhihui Zhao, Wenjiang Wang, Chuangqi Wei, Junfeng Guan, and Christopher Ference

obviously different postharvest properties. ‘Mopan’ persimmon fruit is prone to rapid softening after harvest, leading to limited shelf life. In the short harvest season, large numbers of postharvest losses occur when ‘Mopan’ persimmon fruit are in abundant

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Jianguo Li, Hong Zhu, and Rongcai Yuan

responsible for this difference in PFA among apple cultivars is not clear, but extensive molecular research has revealed that certain groups of genes involved with ethylene biosynthesis, perception, and fruit softening are differentially expressed during fruit

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Cristina Besada, Alejandra Salvador, Lucía Arnal, and Jose María Martínez-Jávega

injury (CI) symptom is softening when fruit are transferred to higher temperature ( Arnal and Del Rio, 2004 ; Salvador et al., 2004 ). Like other fruit, ‘Rojo Brillante’ persimmon showed higher sensitivity to low temperatures when they were picked at

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Domingos P.F. Almeida and Maria Helena Gomes

Flesh softening is a major cause of deterioration in kiwifruit limiting storage life ( MacRae and Redgwell, 1992 ) and affecting consumer acceptability ( Stec et al., 1989 ). Kiwifruit firmness declines rapidly after harvest and is reduced to