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  • Author or Editor: S. W. Porritt x
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Abstract

A delay period of 2 to 6 days at 21°C prior to cold storage of ‘Spartan’ apples (Malus domestica Borkh.) was effective in reducing incidence of breakdown in fruit harvested at 3 maturities. The incidence of decay was higher in immature and overmature fruit than in fruit harvested at optimum maturity. The incidence of core browning was highest in immature fruit and was reduced by a 2 to 6 day delay. Delay in storing fruit was associated with slightly softer fruit at harvest or after 4 months storage, but had no effect on fruit firmness after 7 months storage.

Open Access

Abstract

Exposing ‘Spartan’ or ‘Golden Delicious’ apples (Malus domestica Borkh.) to 38°C for 4 to 6 days immediately after harvest suppressed softening during subsequent storage at −1°C 90 to 94% relative humidity. The rate of acid loss during the period of heating was rapid, but returned to normal during cold storage. Breakdown, core browning, and decay of ‘Spartan’ apple were almost eliminated by the heat treatment. There were no physiological disorders in the ‘Golden Delicious’.

Open Access

Abstract

Low relative humidity (73%–80%) and high relative humidity (94%) lowered the initial rate of calcium penetration from postharvest dip into the tissues of ‘Spartan’ apple fruits (Malus domestica Borkh.). Moderate storage relative humidity (87%) resulted in the most rapid initial uptake of calcium by the tissues. The effect of humidity on calcium movement into the fruit tissue decreased with time in storage.

Open Access

Abstract

In the paper, Texture Modification of ‘Van’ Sweet Cherries by Postharvest Calcium Treatments by P. D. Lidster, S. W. Porritt, and M. A. Tung (J. Amer. Soc. Hort. Sci. 103(4):527-530. 1978), the caption for Fig. 1 should read: Fig. 1. Ca penetration into ‘Van’ cherry. Log ppm Ca = 2.920-0.003430 Day + 0.1536 Log Day (P 1%, R2=0.94). Flesh Ca of undipped control = 545 ppm.

Open Access

Abstract

A delay in storage at 0°C prior to impact damage decreased the incidence of surface disorders due to mechanical damage in ‘Van’ cherries (Prunus avium L.). A 4% CaCl2 plus 0.25% Keltrol postharvest dip reduced the incidence of pitting and surface marking at all delay periods after dipping.

Open Access

Abstract

Calcium (Ca) moved rapidly into sweet cherry fruit (Prunus avium L.) flesh and reached a maximum in 7 days after a postharvest calcium chloride (CaCl2) dip. Flesh Ca content was increased by increasing the CaCl2 or thickener concentration or by prolonged immersion time in the dipping solution. After 21 days of 0°C storage, texture attributes of fruit firmness and bioyield were positively correlated with fresh Ca levels.

Open Access

Abstract

A rapid method for determining firmness of fruits of sweet cherry (Prunus avium L.) using the Ottawa Texture Measuring System is described. Firmness was determined by averaging the mean slope of force-deformation curves for 15 individual cherries per replication. Fruit of intermediate maturity was less from (P < 5%) than more immature or mature fruit Three Ca sprays applied prior to harvest firmed fruit (P < 5%) at harvest. Cherry bioyield and deformation values were not significantly influenced by fruit maturity or CaCl2 sprays at harvest

Open Access

Abstract

In a collaborative study at 5 North American locations, treatment with 12% CO2 and 3 to 5% O2 for 2 weeks at 0° to 3°C at the beginning of controlled atmosphere (CA) storage significantly delayed softening of ‘McIntosh’ apples (Malus domestica Borkh.). Softening was retarded further when treatment time and CO2 concentration were increased, and when fruit was harvested less mature. The effect was diminished by treatment at 0°, and was nullified by delayed treatment and slow cooling during treatment. Softening response to CO2 was not influenced by O2 concentration or storage humidification during treatment. CO2 treatment reduced the rates of CO2 and ethylene evolution from the fruit, even after 4 to 5 months of subsequent CA storage, but affected neither soluble solids nor titratable acidity of fruit after storage. When taste panelists could distinguish CO2-treated from nontreated CA apples, they preferred the treated fruit.

These beneficial results were usually accompanied by external CO2 injury, and occasionally by internal CO2 injury; 30 to 50% of the fruit were injured in some tests. Treatment in a non-humidified room reduced CO2 injury without also reducing treatment benefits. We conclude that for ‘McIntosh’, the potential for injury outweighs the benefits obtained from CO2 pre-treatment in CA storage.

Open Access