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A convenient and reliable method that used a specially designed tool to apply a uniform bruising force in situ was developed to assess the relative susceptibility to fruit surface pitting in sweet cherry. Assessment of pitting with a visual scale after 2 weeks of 1 °C storage was found to be in close agreement with measurements of pit diameter. Using this method `Bing' showed the greatest susceptibility to pitting in both years of the study and `Bing', `Lapins', and `Sweetheart' cherries showed a decline in susceptibility as fruit matured. The predictive value of fruit firmness at harvest, fruit respiration at harvest, and weight loss in storage was assessed in relation to the severity of pitting. The model to best describe pitting was found to include all three physiological variables (firmness, respiration, and weight loss). While an acceptable model was obtained when combining all three cultivars, the best models were achieved when each cultivar was considered separately. It was concluded that there are likely unmeasured variables involved in determining susceptibility to pitting. Hence the best approach to predicting pitting susceptibility is the application of the pit-induction method described in this work.

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Exposure of muskmelon (Cucumis melo L. Group reticulatus) fruit to high temperatures at harvest causes sunbuming, decreases firmness, lessens overall quality (2), and may accelerate fresh weight loss. The purpose of this study was to examine the effect of high prestorage temperatures on muskmelon fresh weight loss and on relative storage life measured as electrolyte leakage of shrink-film wrapped and nonwrapped fruit.

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Cured sweet potatoes [Ipomoea batatas (L.) Lam] were stored successfully at 15.6°C and 90% RH for up to a year without sprouting. Contribution of respiration and transpiration to total weight loss was determined during curing and storage in 6 cultivars. Respiration rate was highest the day of harvest, decreased during curing, and continued to decrease at a slower rate during the first several months of storage, whereafter it remained constant (except for slight increases during the last several months in 2 cultivars). Respiration contributed more to total weight loss during the latter periods of storage than during curing or the first months in storage. Transpiration, however, was the major source of weight loss. The highest rate of weight loss occurred during curing, followed by a gradual rate of loss during storage. Total weight loss of cured roots after 50 weeks of storage ranged from 6.7% (‘Rojo Blanco’) to 16.1% (‘Travis’).

Open Access

The relation between sensory and instrumental measurements of apple texture was investigated to find an effective postharvest texture measurement method of apple. Then nondestructive evaluation of texture and weight loss using NIR was conducted. `Gala' and `Fuji' apples were sampled during storage at 20 °C with 80% to 85% relative humidity. Instrumental measurements included penetration, compression, and bending tests with a texture analyzer, and sensory attributes were finger firmness, hardness, crispness, and mealiness. The penetration test was more effective for postharvest texture measurement than compression and bending tests in the correlation between sensory texture and instrumental measurement. As texture evaluation parameters, elastic modulus (slope before rupture point) and work (area to penetrate) of penetration test were more sensitive than maximum force. Maximum force, generally used as the parameter for texture evaluation, had a little problem under influence of weight loss in `Fuji'; however, elastic modulus and work could detect the texture change of apple under influence of weight loss as well as softening. In the investigation of possibility of nondestructive evaluation using NIR of texture, the MLR analysis for elastic modulus determination of penetration test showed good correlation (R = 0.82, SEP = 2.66) in combination of two cultivars. Also, in the weight loss evaluation, MLR analysis showed the prediction correlation of 0.79 and SEP 1.08 in combination of two cultivars. These results showed the possibility of nondestructive evaluation using NIR of postharvest texture and weight loss.

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Abstract

Broccoli, cauliflower, cucumber, pepper, and muskmelon were displayed (a) in direct sun, (b) in the sun under intermittent mist, (c) in the shade under intermittent mist, (d) in the shade, and (e) on ice at a simulated roadside market for 1-day intervals. In addition, some produce was precooled prior to display. Either ice or the shade under mist treatment was effective in reducing weight loss during display, particularly for broccoli and cauliflower. The prime factor involved in differences in weight loss among crops or between cultivars of the same crop seemed to be the surface area to volume ratio. Precooling prior to display slightly reduced the weight loss for cucumbers and muskmelons but had no effect on the other commodities.

Open Access

To understand the relationship between preharvest water stress and postharvest weight loss, carrot cultivars Eagle and Paramount were grown in muck soil in 6-L pots (eight carrots per pot) in a greenhouse at the Univ. of British Columbia. The plants were watered to field capacity every second day for 4 months before receiving 100, 75, 50, and 25% field capacity water stress treatments, henceforth referred to as low, medium, high, and severe water stress, respectively. Postharvest weight loss of carrots was monitored at 13°C and 32% relative humidity. Carrot weight loss increased with duration of storage in all treatments. It was low in the low-water-stressed and high in severely water-stressed carrots for both cultivars. Root crown diameter, weight, water, and osmotic potential decreased, and specific surface area and relative solute leakage increased with increasing preharvest water stress. Water potential followed by relative solute leakage were the variables that affected weight loss the most. The results show that carrots adjust to water stress by lowering water and osmotic potential. Preharvest water stress lowers membrane integrity of carrot roots making them lose more moisture during storage.

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In the article “Weight Loss in Sweet Potatoes During Curing and Storage: Contribution of Transpiration and Respiration”, by David H. Picha (J. Amer. Soc. Hort. Sci. 111:889–892, November 1986), Figs. 1 and 2 were reversed. The correct figures and captions are printed below.

Open Access

Abstract

Ten cultivars of cabbage (Brassica oleracea v. capitata) were grown in the fall and spring seasons. Cultivar differences in medial and longitudinal head diameter, core length and width, head firmness, and yield were significant within each season. Spring temperatures and daylengths seemed to be more favorable for greater crop production than fall conditions. Growing season significantly influenced head shape and core length. Head shape was conical in the fall, and rounder in the spring. Core elongation was significantly greater in the fall crop. Regression equations show that the percentage of weight loss during storage was lowest at 1°C, and increased with increasing storage temperature.

Open Access

Valencia oranges [Citrus sinensis (L.) Osbeck cv. Valencia] and Marsh grapefruit [Citrus paradisi Macf.] were treated with single or double layers of coating. In cases where two coatings were applied, the first coating was a moisture-barrier wax; the second was either polyethylene wax or a mixture of shellac and resin ester. The inner coating reduced weight loss, and the outer coating imparted gloss. Fruit gloss, as measured by reflectometer, decreased more rapidly during 1 week at 20C with a single glossy coating than with the same coating applied as a second layer over a wax-based first coating. For citrus fruit, using resin ester or shellac as a high-gloss second coating tended to overly restrict the exchange of O2 and CO2; however, two layers of wax did not.

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Abstract

Methods were investigated to control weight loss and sprouting of stored ginger rhizome (Zingiber officinale Rosc), including waxing, sprout inhibitors, and gamma irradiation. Rhizomes stored for 3 months at 22°C and 70% RH lost about 20% weight. Waxing of the rhizome did not reduce water loss. Some wax treatments increased the number and length of sprouts. Preharvest application of maleic hydrazide significantly increased the number and reduced the length of sprouts. Postharvest CIPC application significantly reduced the length of sprouts. Vacuum infiltration increased the effectiveness of CIPC in reducing sprout length. Gamma and X-ray irradiation also reduced sprout number and length. Minimum doses of gamma radiation for sprout control was 25 Gy and 120 to 150 Gy for X-ray irradiation if the rhizome was stored for more than 3 months at 22°. A higher dose of irradiation (500 Gy) was required if complete sprout growth control was needed for storage periods <3 months at 22°. Suberization occurred during curing at 22°, but the suberin layer did not completely protect the cut surface. Chemical name used: isopropyl n-(3 chlorophenyl)-carbamate (CIPC).

Open Access