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The external and internal quality of ‘Fuyu’ persimmon fruit (Diospyros kaki L.) was evaluated after heating with radiofrequency (RF) energy to 48, 50, or 52 °C, holding at the target temperatures for durations ranging from 0.5 to 18 minutes, hydrocooling, and ripening at 20 °C for 12 days. These treatment conditions were identified for control of third instar Mexican fruit fly larvae (Anastrepha ludens). The treatments had no commercially significant effect on firmness, soluble solids content, titratable acidity, or weight loss of the fruit. RF-treated persimmon fruit attained a deeper orange–red skin color than control fruit. There was a greater incidence of slight to moderate flesh browning in fruit heated to 50 and 52 °C as compared with 48 °C. Calyx browning increased slightly in all RF-treated fruit and was the highest in the longer treatments at each temperature. Heating persimmon fruit with RF to 48 °C and then holding for 6 or 12 minutes showed the least damage, and the latter treatment was longer than should be required for a quarantine treatment against the third instar Mexican fruit fly. Holding persimmons for 6.6 minutes at 48 °C should provide control of the Mexican fruit fly and maintain fruit quality. Confirmation tests with infested fruit should be conducted.

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During three consecutive years, 'Bing' sweet cherry (Prunus avium L.) trees were treated during dormancy with the dormancy-manipulating compounds, CH2N2 or CaNH4NO3, or were treated with the plant growth regulator GA3 at straw color development. Fruit of a range of maturities, based on skin color, were evaluated for quality following harvest and simulated transit and market storage conditions. At comparable maturities, CH2N2 and GA3 fruit were of similar firmness and were consistently firmer than CaNH4NO3-treated and untreated fruit across years, storage regimes, and maturities. CaNH4NO3 and untreated fruit were of similar firmness. CH2N2-treated cherries were larger than fruit of other treatments, but only marginally with respect to variation in fruit size between years. Contraction of fruit diameter occurred after 3 days storage, but ceased thereafter up to 11 days storage. Soluble solids and titratable acidity varied between years, storage regimes, and maturities. Strong interactions of treatment and year concealed possible treatment effects on these indices. GA3 fruit contained fewer surface pits in one year while CH2N2 fruit suffered less shrivel in another. The earlier harvest date for CH2N2 fruit often avoided higher field temperatures and the resulting promotion of postharvest shrivel. Pitting and shrivel were more prevalent in stored fruit. Brown stem discoloration developed in storage, occurring most frequently in mature fruit, although methyl bromide-fumigated fruit were particularly susceptible. This disorder was more common in GA3 fruit during years of high incidence. Chemical names used: gibberellic acid (GA3); calcium ammonium nitrate (CaNH4NO3); hydrogen cyanamide (CH2N2).

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The Mexican fruit fly infests many tropical and subtropical fruits, consequently fruits must be treated for quarantine security. Although chemical fumigations are the most common quarantine treatments, interest in using cold and heat treatments has increased due to concerns over environment and human health. Recently, shorter heat treatments such as those provided with radio frequency (RF) energy have been studied on walnuts and various fresh fruits as a possible quarantine treatment. Preliminary studies with a heating block system showed that reaching temperatures of 50 °C with a holding period of 2 min. or 48 °C for 6 minutes was required to achieve 100% insect mortality of 600 third instar Mexican fruit flies (the most heat resistant insect stage). Doubling the holding time required to achieve 100% insect mortality would likely be necessary to provide for Probit 9 security. Fresh fruits such as persimmons and guavas are commonly infested by the Mexican fruit fly. Persimmon and guava fruit were treated with RF energy to temperatures ranging from 48 to 52 °C at different holding periods. After treatments fruit were evaluated for external appearance, decay, soluble solids, titratable acidity, internal flesh quality, and ethylene production and respiration rate. Persimmon fruit tolerated the lower temperature, 48 °C for up to 18 min., but temperatures above 50 °C for more than 1 minute caused internal damage. Preliminary studies with guava indicate that fruit may tolerate 50 °C, but fruit quality after storage is still to be evaluated.

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The efficacy of several proprietary plastic pallet cover systems to maintain strawberry (Fragaria ×ananassa) fruit quality during commercial shipment was determined. ‘Albion’ fruit were harvested from farms near Watsonville, CA. Fruit in vented plastic clamshells were palletized and forced-air cooled to 33–35 °F. Different cover systems (CO2 West, PEAKfresh, PrimePro, Tectrol) were placed over the pallets. Pads that released carbon dioxide (CO2) gas were placed inside the CO2 West cover. The Tectrol cover was sealed to the pallet base, a partial vacuum was applied, and pressurized CO2 gas was injected inside. The systems other than Tectrol remained open at the base. Six separate shipments of palletized fruit were transported in refrigerated (32–39 °F) truck trailers to distribution centers in either Florida or Georgia in 2.3–4.7 days. CO2 concentrations within pallets at the beginning and end of transport were highest (11% to 16%) in the sealed Tectrol system and relatively low (0.06% to 0.30%) in the open CO2 West, PEAKfresh, and PrimePro cover systems. Relative to noncovered control fruit, which lost 0.8% fresh weight during shipment, the pallet covers reduced the transport-related weight loss by 38% to 52%. The incidence of fruit decay was low (1.0% to 1.4%) after transport but increased substantially following a 2-day shelf life at 68 °F. However, fruit from the Tectrol pallets exhibited significantly less decay (36%) after shelf life than the CO2 West (39%), noncovered control (41%), PrimePro (42%), and PEAKfresh (43%) pallets. Fruit sensory quality was unaffected by the different pallet cover systems. Our findings show that transporting strawberries in the sealed Tectrol pallet cover system, in which CO2 concentrations were elevated to 11% to 16%, was most effective in complementing current low temperature management practices to maintain fruit quality.

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Assessing consumer acceptance is an important aspect of cultivar evaluation. Since 2002, about 2700 consumers have participated in pear preference surveys. Surveys were conducted on multiple dates and at multiple venues from 2002 to 2005 in Oregon and northern California. Survey participants were asked to indicate their preference for pears based on size, appearance, taste, and overall preference. They were also asked to indicate what attributes they liked or disliked about their favorite and least favorite varieties and to indicate their level of purchase intent. Each survey consisted of four to six cultivars, including at least one standard commercial comparison; i.e., Bartlett, Bosc, or Anjou. Data was analyzed (RCBD; Friedman Analysis of Rank or ANOVA/Tukey's HSD) at the OSU Food Innovation Center Experiment Station using Compusense® five v.4.6 software (Guelph, Ont., Canada). Results indicated several alternative possibilities for both summer and winter sales. Among the most preferred cultivars (variable between states) were Anjou (commercial standard winter pear), Bartlett (commercial standard summer pear and most-consumed cultivar), Blake's Pride, Cinnamon, Concorde, and 71655-014. Other major findings were preference for large pears for adults and small for children, overall liking based on sweetness and flavor rather than skin color, and general lack of knowledge of many commercial pear cultivars. Sensory evaluation surveys will be continued in 2006 in California, with focus on differential harvest times for selected preferred cultivars. Consumer preference data is being combined with production and postharvest quality data in order to provide the pear industry a comprehensive data set on potential alternative cultivars.

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Preharvest applications of 1-methylcyclopropene (1-MCP) were tested on California ‘Bartlett’ pears at 80 N maturity and at rates of 0, 28, and 56 mg·L−1 in 2006 and 0, 50, and 100 mg·L−1 in 2007. In 2007, a parallel experiment was conducted to compare 50 mg·L−1 1-MCP with 96 g a.i./ha 1-naphthaleneacetic acid (NAA) used commercially to control or decrease premature fruit drop. Premature fruit drop, maturity, firmness at harvest, color, softening, and ethylene production during ripening and physiological disorders were studied in fruit harvested between 7 and 21 days after 1-MCP application and either ripened at 20 °C immediately after harvest or after 3.5 to 6 months storage at –1 °C. Overall, 50 mg·L−1 1-MCP reduced the incidence of premature fruit drop when compared with the untreated fruit and fruit drop was similar to adjuvant-treated fruit and NAA-treated fruit, especially 28 days or longer after the treatment. 1-MCP was more effective in retarding color, softening, and ethylene production during ripening than delaying fruit maturation on the tree (loss of firmness), and both rates of 1-MCP tested each season yielded similar fruit responses on most evaluation times. 1-MCP's effect on ripening was lost if fruit remained on the tree 21 days or after the fruit were stored for 3.5 months in cold storage regardless of treatment concentration. A reduction of internal breakdown incidence was observed in 1-MCP-treated fruit.

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As part of a larger project to show how fresh fruits and vegetables with enhanced flavor can be successfully handled to improve consumer satisfaction without compromising food safety, key informant interviews were conducted with fruit industry leaders dealing with melons (Cucumis melo and Citrullus lanatus), peaches and nectarines (Prunus persica), pears (Pyrus communis), tomatoes (Solanum lycopersicum), strawberries (Fragaria ×ananassa), and blueberries (Vaccinium sp.). The interview was designed to collect information on industry attitudes and practices related to postharvest handling of more mature fruit, harvest timing, preconditioning, cold chain management, and shipping and handling procedures throughout the supply chain. The current analysis focuses on two key questions from the interviews: 1) To what extent do industry experts believe that better fruit handling and shipping procedures contribute to better taste quality in fruit? 2) To what extent do industry experts believe that better fruit quality will lead to more consumer purchasing? In response to the first question, the majority of respondents (70%) agreed that postharvest handling affects fruit flavor with the most cited themes related to agreement being gentle handling, cold chain management, and harvest timing. Of the respondents who expressed disagreement most acknowledged the importance of postharvest handling, but felt other factors were also important, mainly the variety grown, the shelf life requirements, and the growing conditions. For the second question, 95% of respondents agreed that increased taste quality of fruit would mean increased purchasing and consumption. The primary theme related to agreement was that consumers would repeat purchase after positive eating experiences. Other important factors were the price point of fruit, retail display, product identity, and fruit appearance. With increasing consumer attention to fruit quality and a generally accepted belief among industry representatives that fruit flavor and quality drives consumer demand, there is an opportunity to shift industry practices toward postharvest handing that is conducive to consistently delivering better-tasting fruit to consumers.

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