Organoleptic evaluations of shrink film-wrapped and nonwrapped musk-melon (Cucumis melo L. var. reticulates cv.. TAM Uvalde) fruit were conducted to determine changes in flavor and taste during refrigerated storage. Ripe green and yellow `TAM Uvalde' muskmelons, shrink film-wrapped in 12.7-μm high-density polyethylene film, were compared to nonwrapped melons during 21 days of storage at 4C and 90% to 95% RH. After 21 days of storage, both yellow and green shrink-wrapped melons had better appearance, less surface mold, and less vein tract browning than nonwrapped melons. However, the flavor and taste of shrink-wrapped fruit were significantly inferior to those of nonwrapped melons. Green-wrapped melons were rated poorer in taste and flavor than yellow-wrapped and nonwrapped melons after 14 days of storage. These results indicate that shrink-wrapping may enhance undesirable flavor changes in muskmelon during storage.
J.K. Collins, B.D. Bruton and P. Perkins-Veazie
Noida A. Biglete, Robert F. Testin and James W. Rushing
A triploid watermelon cultivar, `Crimson Trio' and a seeded cultivar, `Mirage', were shrink-wrapped in four different films: Cryovac D940, Cryovac D955, and Magellan film with and without a blended biocide. Unwrapped fruits served as the control. Fruits were stored at either 1.5, 10 and 21°C for three weeks plus an additional week at 21°C to simulate retail marketing. Total soluble solids (TSS) and pulp color measurements were taken after harvest and at the end of the storage period while weight, disease incidence, chilling injury and visual quality rating were monitored at weekly intervals. Results showed that the seedless variety have better postharvest qualities in terms of storage life, TSS and chilling resistance than the seeded variety. Wrapped fruits had less weight loss, higher TSS and better rind color than the unwrapped fruits at the end of the storage period. However, all wrapping treatments, including the biocidal film increased disease incidence compared to unwrapped controls. Also, wrapping did not alleviate chilling injury, which was most severe in fruits stored at 1.5°C and then held at 21°C for one week.
Robert A. Saftner, William S. Conway and Carl E. Sams
Lustr 221 and D955 shrink-wrap film, respectively. We also are grateful to Willard Douglas for technical help related to internal and external gas measurements. Use of a company name or product by the USDA does not imply approval or recommendation of the
Robert A. Saftner
The effects of harvest-applied coating and shrink-wrap polymeric film treatments of apples [Malus ×domestica Borkh. `Gala' and Mansf. `Golden Delicious'] on volatile levels, quality attributes, respiration, and internal atmospheres after storage at 0 °C for 1 to 6 months, and during subsequent shelf life at 20 °C were investigated. Over 30 volatiles were detected, most of the identified volatiles were esters, the rest were alcohols, aldehydes, a ketone and a sesquiterpene. Shellac- and wax-based fruit coatings transiently inhibited total volatile levels in `Golden Delicious' while not affecting those in `Gala' apples during 6 months of storage in air at 0 °C. Holding fruit at 20 °C for up to three weeks following cold storage increased volatile levels with coated and nontreated fruit having similar amounts. Only shellac-coated `Golden Delicious' apples accumulated ethanol and ethyl acetate when held at 20 °C. The shrink-wrap polymeric film treatment had no effect on fruit volatile levels during cold storage or during subsequent shelf life at 20 °C. Coating but not film treatments reduced respiration and ethylene production rates that were observed upon transferring the fruit to 20 °C. Internal CO2 and ethylene levels increased and O2 levels decreased in coated fruit. The coating treatments led to better retention of flesh firmness in `Golden Delicious' but not `Gala' apples. Coating and film treatments reduced fresh weight loss in both cultivars during cold storage. The results suggest that harvest-applied coating and film treatments having relatively high permeability for CO2 and O2 and relatively low permeability for water vapor and fruit volatiles have potential for improving the storage and shelf-life qualities of `Gala' and `Golden Delicious' apples.
Arthur Villordon, Jeffrey C. Gregorie and Don LaBonte
root VOL and SA that involved capturing images of samples, extraction of features, and inputting these data into predictive equations. LaBonte and Wright (1993) described the procedure for using a shrink-wrap method to measure sweetpotato SA
N.H. Furness, A. Upadhyaya and M.K. Upadhyaya
Surface areas of differently shaped vegetables, namely beet (Beta vulgaris L.), cucumber (Cucumis sativus L.), carrot (Daucus carota L.), and parsnip (Pastinaca sativa L.) were determined by Baugerod's (a linear) method, a shrink-wrap replica method, and image analysis. Values obtained using these methods did not differ significantly for carrots and beets. Surface area values obtained using image analysis were higher than those obtained by Baugerod's method for parsnips (by 23.5%), and higher than Baugerod's and shrink-wrap replica methods for cucumbers (by 11.3% and 12.6%, respectively). A method was considered reproducible if surface area values from five measurements on the same product did not differ significantly (P ≤ 0.05). Surface area values for an individual product varied in the range of 4.7% for Baugerod's method for parsnips, and 6.6% for the shrink wrap replica method for carrots. No significant variation was observed for any of the vegetables when repeated measurements were made using the image analysis method. Image analysis offers rapidity, lack of adverse effect on produce, and the ability to collect and analyze data simultaneously. However, in absence of the necessary equipment for image analysis, Baugerod's method may be used for a product symmetrical around its central axis, after comparing it with a more direct procedure (e.g., shrink-wrap replica method).
Robert A. Saftner, William S. Conway and Carl E. Sams
`Golden Delicious' apples were pressure-infiltrated (34 kPa) at harvest with 0, 20, 35, or 50 g·L–1 solutions of CaCl2 followed without and with a water rinse, a wax or shellac emulsion treatment, or a shrink-wrap packaging, and stored at 0°C. The CaCl2 treatments delayed senescent breakdown, but also caused superficial injury to the fruit. A water rinse in combination with a wax- or shellac-based coating or shrink wrap packaging reduced the appearance of superficial injury in fruit treated with 35 or 50 g·L–1 solutions of CaCl2 and eliminated it in fruit treated with a 20 g·L–1 solution of CaCl2. While reducing the risk of calcium-related injury to the fruit, the coating and film treatments maintained the beneficial effects of calcium on apples and reduced weight loss of the fruit during cold storage.
P.M. Perkins-Veazie, V. Russo and J.K. Collins
Radicchio, also known as red-leaved chicory (Cichorium intybus L.), is a high value vegetable crop. Few postharvest characteristics have been described for this crop. Five cultivars of radicchio were held at 1 and 10C in plastic boxes or shrink-wrap bags to determine postharvest quality changes. Weight loss was similar at both temperatures for all cultivars. Major quality losses of radicchio held in shrink-wrap or plastic boxes at 1C were caused by leaf browning. Shrink-wrapping prevented leaf shrinkage and bleaching, but enhanced decay at 10C. The respiration rate of radicchio heads held at 1C was initially 7.4 ml· CO2 kg-1 · h-1, then fell to 3 ml CO2 ·k g-1 · h-1 after 7 days of storage at 1C. Respiration at 10C was maintained near 19 ml·k g-1· h-1 through the duration of the experiment. Shrink-wrapped radicchio held at 1C had marketable quality for 5 weeks.
Horseradish (Armoracia rusticana) has one of the highest rates of postharvest weight loss among all vegetable crops. Postharvest studies were conducted to identify improved methods of extending the market life of fresh horseradish roots. Postharvest treatments included submerging or coating thoroughly washed and dried roots in chlorine (150 ppm), hydrogen dioxide (Storox), 2,6-dichloro-4-nitroaniline (Botran), carnauba-based wax, shellac-based wax, paraffin wax, and polyolefin shrink film (75–100 micron thickness). Two treatments, shrink wrapping and paraffin waxing, were superior in reducing postharvest weight loss and extending horseradish root market life. Roots from the non-paraffin waxed and nonshrink-wrapped treatments lost an average of 20% weight after only 4 days of ambient temperature storage. This resulted in significant root shriveling and unacceptable market appearance. Roots from the shrink wrapped treatments lost an average of 1% weight after 4 days of ambient temperature storage, while paraffin waxed roots lost about 3% weight. It is important to thoroughly dry the roots before shrink wrapping, to avoid moisture condensation on the inner surface of the film and subsequent microbial growth. All of the shrink-wrapped roots and paraffin waxed roots were marketable after 14 days of ambient storage, and no surface mold was detected. Less than 3% weight loss occurred after 14 days of ambient storage in all shrink-wrapped roots, while paraffin-waxed roots lost about 9% weight. Weight loss in the unwrapped roots from the other postharvest treatments ranged from an unacceptably high 44% to 48% after 14 days.
M.K. Upadhyaya and N.H. Furness
Surface area of cucumbers, carrots, parsnips, and beets was determined using the following non-destructive methods: Baugerod's method, Baugerod's method with inclusion of a factor correcting for substitution of weight for volume in the formula, and a novel image analysis method. Accuracy of the methods was ascertained by comparison with a direct shrink-wrap replica method of surface area measurement. Vegetables ranged in shape from cylindrical (cucumber and carrot) to conical (parsnip and beet). No difference in accuracy among methods of surface area determination was detected for carrots or beets. Baugerod's method and the image analysis technique differed significantly from the direct shrink-wrap replica technique for surface area determination of parsnips and cucumbers, respectively. Inclusion of a correction factor in Baugerod's method did not increase the accuracy of this method for any of the vegetables. The precision and repeatability of each method was determined by repeated measures analysis. Baugerod's method lost precision and repeatability for the conically shaped vegetables. Conversely, the shrink-wrap replica method lost precision and repeatability for the cylindrically shaped vegetables. The image analysis technique was precise and highly repeatable over the range of vegetable shapes. The development of a rapid, accurate, and precise non-destructive method of surface area measurement using image analysis techniques will provide a useful tool in the physiological study of vegetable products. Applicability of such a method over a range of vegetable shapes will be of additional value.