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- Author or Editor: J.K. Collins x
The effects of retail-display packaging on strawberry fruit quality were studied using freshly harvested `Cardinal' strawberries. Fruit free from blemishes and disease were placed into plastic vented boxes, covered with vented plastic lids or plastic wrap, and placed at 1 and 5C overnight One-half of the treatments were removed from coolers, held at 25C for eight hours, returned to the coolers and evaluated over a 15-day storage period. The plastic overwrap greatly decreased weight loss during 15 days of storage; carbon dioxide reached 0.8 and 2% per mg fresh weight at 1 and 5C, respectively. Type of cover did not affect overall appearance or disease ratings. Exposure of fruit to 25C for eight hours led to no loss of overall quality. Storage of fruit at 50C led to greater disease incidence and loss of quality. The respiration rate of fruit warmed at 25C reached equilibrium after six hours, regardless of initial storage temperature. Fruit in vented dome-lid boxes had more weight loss than plastic-wrapped boxes at both temperatures.
Okra pods are highly perishable due to a high respiration rate and chilling sensitivity. The purpose of this experiment was to evaluate okra cultivar response to package and storage temperature. Freshly harvested `Annie Oakley', `Blondy', `Burgundy', `Clemson Spineless' and `Emerald' okra pods were placed in plastic boxes and shrink-wrap bags. Pods were evaluated for weight loss, chilling injury and electrolyte leakage during 8 days of storage at 12.5 and 3°C. Weight loss was similar for all cultivars at both temperatures, but it was much less when pods were stored in bags compared to boxes. Percent electrolyte leakage was similar for all cultivars before storage. `Blondy' displayed the most severe chilling injury after 8 days of storage at 3C while `Emerald' had few symptoms of chilling injury. After 8 days of storage, all cultivars except `Emerald' had increased electrolyte leakage. These results indicate that okra pods have increased membrane permeability with chilling injury, and the degree of chilling injury may differ with cultivar.
Okra develops chilling injury after 4 to 5 days at 2C or 8 days at 5C. Intermittent warming has prevented or delayed chilling injury in warm season crops. The purpose of this experiment was to find a way to prevent or delay chilling injury in okra. Field grown `Annie Oakley', `Blondy', and `Clemson Spineless' okra pods were held constantly at 2, 5, or 10C or placed at 2C or 5C for 2 days followed by 2 days at 10C (2-10 and 5-10, respectively) then returned to their original temperature. After 8 days of storage, all boxes were placed at 20C for 1 day; color was measured with a colorimeter, and pods were rated subjectively for chilling injury. `Annie Oakley' and `Clemson Spineless' pods held at 2C were olive-green to brown; okra held at 2-10 was green and still marketable. Less chilling injury occurred to pods held at 5 and 5-10 compared to those at 2C. Pods held at 2-10, 5, or 5-10 had injury after 8 to 10 days of storage compared to 5 days at 2C. Although chilling injury could not be completely prevented in okra by intermittent warming, shelf life could be lengthened by cooling pods at 2C for no more than 2 days to eliminate field heat and reduce weight loss, followed by storage at a higher temperature.
Application of modified-atmosphere storage (MA) (high carbon dioxide and/or low oxygen) extends the shelf life of several fruits. This study was done to determine the effects of MA on quality and flavor of blackberries. `Navaho' and `Arapaho' blackberries were harvested in 1998 and 1999, precooled overnight at 2 °C, and placed in 0.5-L treatment jars. Treatments of 15% CO2/10% O2 or of air (0.03% CO2/21% O2) were applied at 2 °C for 3, 7, or 14 days. After treatment application, jars were held at 2 °C for an additional 11, 7, or 0 days, respectively. Seven and 14 days of application of CO2 reduced the incidence of decayed and leaky berries by 10% to 20% for both `Arapaho' and `Navaho', but firm berries decreased 10% after 14 days of treatment. Titratable acidity was slightly lower, and pH higher, in control fruit but soluble solids content was not affected by treatment. Anthocyanin content was not affected by treatment in `Arapaho' berries but was lower in `Navaho' berries after 7 and 14 days of treatment. Samples taken for taste tests after 3 and 7 days of treatment had no off-odors or off-flavors. `Arapaho' and `Navaho' blackberries benefitted from high CO2 storage, with a minimum of 7 days of treatment application needed to increase marketable berries by 10%.
The red flesh of watermelon contains lycopene, a pigment with antioxidant properties that help prevent certain types of cancers. This experiment was done to determine cultivar variation in lycopene content, and the effectiveness of colorimetric measurements for predicting lycopene content. Ten ripe melons per cultivar of hybrid, open-pollinated, and triploid types were selected from field plantings at Lane, Okla. Melons were cut transversely and color measured with a colorimeter at three heart and three locule sites, in a counterclockwise rotation starting at the ground spot. For lycopene content, a 100-g sample of heart tissue was removed, extracted with a hexane-acetone-ethanol mixture, and lycopene concentration measured spectrophotometrically at 503 nm. Lycopene content varied among cultivars, from 33.96 μg·g–1 in `Crimson Sweet' to 66.15 μg·g–1 in `Crimson Trio'. Chroma and “a” colorimeter values were highly correlated with lycopene content (P < 0.001). Linear and quadratic regression of lycopene against colorimeter values yielded an R 2 of 0.55. Results indicate that, like tomatoes, watermelon cultivars vary widely in lycopene content. Colorimeter readings did not adequately predict lycopene values.
Small fruit are rich in several types of phytochemicals, vitamins, and minerals. These compounds have health functional properties that may protect humans from cardiovascular disease and certain cancers. Several of these phytochemicals, such as dietary fiber, anthocyanins, and polyphenolics, also contribute to small fruit quality. Other components contribute to appearance and taste. Nonvolatile organic acids contribute to the perceived sourness of small fruit and changes in levels can alter visual color by affecting cellular pH and anthocyanin structure. The soluble sugars glucose, fructose, and sucrose contribute directly to the perceived sweetness of the fruit and provide carbohydrates for other metabolic functions such as phenolic and ascorbic acid synthesis.
Okra stored at 3C in 12.7-pm high-density polyethylene (HDPE) bags developed less chilling injury than fruit stored in plastic boxes. Okra held in HDPE bags at 12.5C for 8 days had more decay and reduced overall appearance than fruit held in plastic boxes. `Emerald Green' okra lost more weight in storage than the other four cultivars regardless of temperature or storage duration, while `Blondy' had the most decay. `Annie Oakley' and `Clemson Spineless' had better shelf life than the other cultivars.
Harvesting raspberry fruit with an attached receptacle prevents compression of the fruit in storage containers and permits harvesting of immature fruit. This study was done to determine the effects of receptacle retention on fruit quality during storage. `Heritage' raspberry fruit from Oregon and Arkansas were harvested at light red (red ripe) and dark red stages of maturity, and stored at 2C, 95% RH for 7 days. Dark red fruit with receptacles were firmer than those without receptacles, but there were no differences in light red fruit. Ethylene production was higher from raspberries stored with receptacles. Total anthocyanin increased in all fruit after storage and was slightly higher in fruit without receptacles. Soluble solids concentration did not change but titratable acidity decreased during storage for all treatments. When fruit were harvested after several days of rain, decay incidence in fruit held with receptacles increased. Harvesting raspberries with attached receptacles did not increase postharvest fruit quality.
Reports on the lycopene content of tomatoes vary widely with country and source of fruit (field, greenhouse, retail). This study was done to compare the lycopene content of organically grown tomatoes, and to compare fully red fruit to those ripened after harvest. Thirteen tomato cultivars (12 beefsteak and one Roma type) were planted in land designated as transitional organic and fertilized with organic poultry litter. No additional fertilizer was applied. Pesticides approved for organic use were applied as necessary. Fruit at the turning to firm red stages were harvested and held at 20 to 28 °C until the soft red stage was reached (about 2 to 8 days). Day 0 fruit at pink to soft red stages was harvested at the same time. Multiple harvests were made for 6 weeks, until 10 fruit per cultivar and ripeness stage and storage treatment were obtained. Lycopene content of firm red and soft red fruit were similar, and was 50 to 65 mg·kg–1 for all the round fruit types, and 115 mg·kg–1 for the Roma type. Fruit ripened after harvest without ethylene were able to obtain similar levels of lycopene, even in those fruit harvested with just a trace of color. `Sunmaster' and `Solar Set' tomatoes grown organically were similar in lycopene content to those grown in previous years in a conventional production system. These results show that organically grown tomatoes can achieve normal to high levels of lycopene. Tomatoes ripened after harvest without ethylene can achieve the lycopene content of fruit harvested fully ripe.
Lycopene is a pigment that imparts a red or red–orange color to some fruits and vegetables. This carotenoid has been extensively studied over the last 10 years because of its potent antioxidant activity and medical evidence that dietary intake can reduce the incidence of cardiovascular disease and some cancers. The purpose of this review is to provide researchers in the areas of horticulture and food science a current summary of available information on lycopene in plants, stabilization and extraction, and potential health benefits as delineated in current medical studies.