'Elberta' peaches (Prunus persica L.) harvested 6 days apart were treated with 0.5 mL·L-1 1-MCP for 4 hours at 20 °C then stored at 0, 5, 10 or 20 °C. Fruit were ripened at 20 °C for 3 days after 1, 3, and 6 weeks of storage at 0, 5, and 10 °C. Treatment with 1-MCP delayed the onset of climacteric ethylene production and reduced respiration in fruit held at 20 °C. 1-MCP-treated fruit were firmer than untreated controls after storage at 0 or 5 °C. 1-MCP-treated fruit also had higher titratable acidity (TA) after 1 week of storage at 0 or 5 °C, but TA was lower compared to controls after 3 or 6 weeks of storage. Fruit stored at 5 °C had more severe internal browning, lower extractable juice and TA than fruit stored at either 0 or 10 °C, however, 1-MCP treated fruit had more severe internal browning than untreated fruit after 3 and 6 weeks of storage at 5 °C. Fruit from harvest 1 treated with 1-MCP and stored at 0 °C for 6 weeks failed to soften after removal from storage. Chemical name used: 1-methylcyclopropene (1-MCP).
X. Fan, L. Argenta, and J.P. Mattheis
Kevin M. Keener, Richard L. Stroshine, and John A. Nyenhuis
A 5.40-MHz NMR system was used for measuring the self-diffusion coefficient of water (Dw) and the spin-spin relaxation constant (T2) in apple (Malus ×domestica Borkh.) tissue. The pulsed field gradient spin echo (PFGSE) technique was used to measure Dw, and the Carr-Purcell-Meiboom-Gill (CPMG) technique was used to measure T2. T2 and Dw values were compared for apples with differing amounts of soluble solids concentration (SSC) and with and without internal defects, such as bruising, watercore, and internal browning. `Granny Smith', `Golden Delicious', and `Delicious' apples were tested. In `Golden Delicious', Dw highly correlated with apple tissue SSC (P < 0.002, r 2 = 0.68). This indicates that Dw could potentially be used for sorting `Golden Delicious” apples based on SSC, but the coefficient of determination needs to be improved before it would be commercially viable. There were no measurable differences in Dw among healthy apple tissue and tissue affected by either watercore or internal browning. T2 values showed no relationship between healthy apple tissue and bruised tissue in `Golden Delicious' and `Granny Smith'. However, in `Delicious' tissue, T2 values were statistically different between healthy and bruised tissue (P < 0.02). Further comparisons in `Delicious' between watercore and healthy apple tissue showed no differences. But, there were statistical differences found between T2 in healthy apple tissue and tissue with internal browning (P < 0.01). These results indicate that T2 could potentially be used for separating `Delicious' apples with internal browning or with bruising from healthy apples. Titratable acids and pH were correlated for `Golden Delicious' (P < 0.08). This correlation is significant because one may be able to noninvasively measure pH in `Golden Delicious' apples using NMR, which could then be correlated to titratable acids.
James Mattheis and David R. Rudell
risk can be managed by a conditioning period at 10 to 20 °C after harvest, before storage at a lower temperature ( Contreras et al., 2014 ; DeLong et al., 2004a ; Watkins et al., 2004 ). CA storage of ‘Honeycrisp’ can induce internal browning
Corina Serban, Lee Kalcsits, Jennifer DeEll, and James P. Mattheis
acidity (TA) loss during air storage ( DeEll, 2010 ). Postharvest applications of 1-MCP also can increase CA-related internal disorders such as CO 2 injury, cavities, and internal browning ( DeEll, 2010 ; Watkins and Nock, 2012 ). ‘Honeycrisp’ is a
Carlos H. Crisosto, R. Scott Johnson, Juvenal G. Luza, and Gayle M. Crisosto
The effect of irrigation management strategies on the quality and storage performance of `O'Henry' peaches [Prunus persica (L.) Batsch] was studied for two seasons. The deficit irrigation treatment induced a higher fruit soluble solids concentration and lower fruit weight. The excess irrigation treatment, compared to the optimum treatment, increased the rate of fruit water loss without altering fruit quality and storage performance. Scanning electron microscope observations indicated a higher density of trichomes on fruit from the deficit and optimum irrigation treatments than from the excess irrigation treatment. Light microscopy studies indicated that fruit from deficit and optimum irrigation had a continuous and much thicker cuticle than fruit from the excess irrigation treatment. These differences in exodermis structure may explain the high percentage of water loss from fruit from the excess irrigation treatment compared to the deficit and optimum irrigation treatments.
Jennifer DeEll and Behrouz Ehsani-Moghaddam
. After nine months of CA storage, however, ‘Spartan’ fruit treated twice with 1-MCP had a significantly higher incidence of internal browning than those treated once or not treated ( Table 5 ). Some internal browning also developed in ‘McIntosh’ after
Carlos H. Crisosto, R. Scott Johnson, Kevin Day, and Ted DeJong
Studies on the influences of “orchard factors” such as cultivar, harvest time, crop load, fruit canopy position, irrigation, and nitrogen regimes were investigated for plums, nectarines, and peaches at the Kearney Agricultural Center (San Joaquin Valley, Calif.a). These preharvest factors affected internal browning and mealiness incidence differently. More-reliable benefits of treatments to eliminate or reduce internal breakdown may be accomplished by using outer canopy fruit. Optimum quality expression and subsequent consumer satisfaction for each cultivar can be achieved by understanding the role of preharvest factors and harvest time on fruit quality and potential postharvest life.
Björn H. Karlsson, Jiwan P. Palta, and Peter M. Crump
Our previous research has provided evidence that in-season calcium applications can increase tuber calcium and improve tuber quality with reduced internal defects. To determine if increasing the tuber calcium concentration also mitigates tuber bruise incidence, five commercially relevant potato (Solanum tuberosum L.) cultivars (`Russet Burbank', `Atlantic', `Snowden', `Superior', and `Dark Red Norland') were grown during three seasons, 1999–2001. Three split applications of a calcium/nitrogen water soluble blend totaling 168 kg·ha–1calcium were made starting at hilling. All plots, including controls, received an equal amount of total nitrogen in a season. Tubers were allowed to be bruised during normal machine harvest standard to commercial production in Wisconsin. Over 100 tubers from each replication (5–10 replications/treatment) were cut and examined for the incidences of bruise and internal brown spot. Paired samples of medullary tissue were taken for measuring calcium concentration. As expected, tuber tissue calcium concentration increased significantly, in all cultivars and in all years, with in-season calcium application. Bruise incidence varied among cultivars and seasons. Although tuber calcium concentration varied among seasons, `Atlantic' and 'Snowden' consistently had the lowest calcium concentration, whereas `Superior' and `Dark Red Norland' consistently had the highest calcium concentration. Meta-analysis of pooled data for three years showed that blackspot bruise incidence was significantly reduced with calcium application in `Atlantic', `Burbank', and `Snowden'. On the other hand, `Dark Red Norland' and `Superior' had low incidence of bruise and were unaffected by calcium applications. Regression analyses of pooled data from all cultivars for three years revealed a significant quadratic relationship between blackspot bruise and tuber tissue calcium as well as between blackspot bruise and internal brown spot. A linear to plateau plot of medullary calcium concentration versus blackspot bruise incidence revealed that bruise incidence is minimized between 200 and 250 μg/kg (dry wt)–1 tuber calcium concentration. To our knowledge, ours is the first study providing evidence for reducing bruise by improving tuber calcium. Variations in the bruise incidences among cultivars generally followed tuber calcium concentration suggesting a genetic control. Given the role of calcium in improved membrane health and enhanced wall structure, and as a modulator of physiological responses, it is not surprising that internal brown spot and bruise incidences are reduced by in-season application to calcium-deficient cultivars.
J.L. Smilanick, F. Mlikota, P.L. Hartsell, J.S. Muhareb, and N. Denis-Arrue
`Ruby Seedless', `Red Globe', and `Prima Red' table grapes were fumigated with the treatment schedule of the USDA-Animal Plant Health Inspection Service recommended for the control of mealybugs. Methyl bromide was applied at 64 g·m-3 (4.0 lb/1000 ft3) for 2 h at 16.1 to 18.3 °C (61 to 65 °F). The grapes were in commercial packages typical for each cultivar. After fumigation and 30 min of aeration, the grapes were stored 2 to 4 weeks at 5 °C (41 °F) and their quality assessed by evaluation of cluster rachis condition, shatter, berry cracking, decay, berry color, internal browning, bleaching injury, and firmness. None of the table grape quality parameters was significantly influenced by methyl bromide fumigation.
Zhengke Zhang, Yu Zhang, Donald J. Huber, Jingping Rao, Yunjing Sun, and Shanshan Li
‘Fuyu’ perisimmon fruit were treated with 500 nL·L−1 1-methylcyclopropene (1-MCP) for 24 h at 20 °C and then stored at 4 °C for 45 days to investigate the effects of 1-MCP on chilling injury (CI) during storage at 4 °C. Persimmon fruit developed CI, manifested as rapid softening and external and internal browning. Injury symptoms were reduced by 1-MCP treatment. 1-MCP also delayed increases in respiration and ethylene production. Compared with control fruit, 1-MCP-treated fruit exhibited increased superoxide dismutase and catalase activities within the initial storage period and lower membrane permeability, malondialdehyde content, and peroxidase and polyphenol oxidase activities throughout the entire storage period. These results suggest that reduction of CI symptoms in persimmon fruit in response to 1-MCP treatment may be attributed to altered oxidative status.