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Abstract
Ripening-initiated ‘Valery’ bananas (Musa sp.) held in gas mixtures containing 10 ppm ethylene, 2 to 10% O2 and 0 to 10% CO2, ripened at a slightly lower rate than in air and had comparable quality when ripe. Fruit ripened very slowly and had lower quality, however, when the O2 concentration was reduced to 1%. Ethylene gas, which was released from ethephon ((2-chloroethyl)phosphonic acid) solution applied to a small piece of sponge, initiated ripening of bananas in polymeric film packages. Three kinds of film regulated atmospheric composition inside packages suitable for banana ripening and holding. Making 1 or 3 pin holes through the film package increased the O2 concentration but had little effect upon CO2 and ethylene concentration. Bananas ripened with ethephon in suitable film packages had good eating quality and a longer shelf life than bananas ripened in air.
Abstract
Exposure to 40°C for 72 hours did not promote ripening of ¾ developed ‘Dwarf Cavendish’ bananas (Musa sp.) which had a preclimacteric period of >32 days at 21°. Bananas which were more advanced in physiological age and hence had a shorter preclimacteric period were more sensitive to heat. Twelve to 24 hours exposure to 40° promoted rapid ripening of bananas with an advanced physiological age. Treatment with 0.01 to 0.10 ppm ethylene at 40° created similar effects after shorter periods of exposure in comparison to the control. Internal ethylene was not increased by high temperature but was increased roughly 0.1 ppm by 0.1-ppm external ethylene treatment. Green bananas were more sensitive to ethylene at 40° than at 21°.
Abstract
Ten to 100 ppm ethylene in air inhibited the development of superficial senescent spots on ripe bananas (Musa cavendishii Lambert cv. Valery). The ethylene did not affect the respiration rate but accelerated softening of the partially ripe or ripe bananas at 21°C. Six days of continuous exposure to 10 ppm ethylene did not affect the eating quality of bananas but 9 days of exposure slightly lowered the quality. Ethylene did not inhibit anthracnose (Gloeosporium masarum Cke. & Mass.) growth on banana fruit or on petri dish culture. Dipping ripe bananas in 100 to 1000 ppm (2 chloroethyl)phosphonic acid (ethephon) did not inhibit the senescent spot development. Brief dipping in silver nitrate solution (50 mg/liter) counteracted the ethylene effect.
Abstract
‘McIntosh’ apples (Malus domestica Borkh.) were harvested on 3 different dates and stored in controlled atmosphere (CA) storage with less than 1, 10 or 500 ppm ethylene. After 5 and 8 months of storage the fruits which had been harvested 5 to 6 days before the onset of the climacteric were less ripe and had less breakdown than fruits harvested after the onset of the climacteric. The fruits harvested at the preclimacteric stage had either comparable or slightly better eating quality but less red color than fruits harvested later. High levels of ethylene had slight but statistically significant negative effects on firmness and acidity of early harvested fruits judged by sensory evaluation after 5-month storage plus 7-day holding and by objective evaluation after 8-month storage plus 1- or 7-day holding at 21°C. An attempt was made to find a method to estimate the physiological age of preclimacteric apples. The minimum treatment time required for 10 ppm ethylene to trigger the onset of the climacteric at 21°C is judged to be promising.
Abstract
Five cultivars of apples (Malus domestica Borkh.) each with 2 different harvest dates were stored in continuous flow controlled atmosphere (CA) at 3% O2 and 3% CO2 at 0°C or 3.3° for 3 to 7 months. Ethylene in the CA was maintained at 3 levels: low (mostly below 1 ppm, maximum 3.8 ppm), 10 ppm and 500 ppm. In comparison with low ethylene, 10 ppm and 500 ppm ethylene in CA did not significantly affect the soluble solids, titratable acids, firmness and sensory evaluated ripeness of ‘Delicious’, ‘Golden Delicious’, ‘Indared’ and ‘Cortland’ apples harvested on either date and of ‘McIntosh’ apples harvested after the onset of climacteric. However, ‘McIntosh’ harvested before the onset of climacteric retained higher acids, firmer texture and were sensory evaluated as less ripe when kept in CA with low ethylene than that with 10 or 500 ppm ethylene. ‘Delicious’ apples stored for 7 months in CA with 10 or 500 ppm ethylene developed severe scald but those in CA with low ethylene did not.
Abstract
Daminozide-treated and non treated ‘Delicious’ and ‘Idared’ apples (Malus domestica Borkh.) were stored for 7 to 7.5 months in simulated low-ethylene (<1 μl·liter−1) or normal-ethylene (500 μl·liter1) controlled-atmosphere (CA) storage. The simulated CA storage was a flow-through CA storage in 19-liter jars at 0°C. The storage atmosphere contained 2.5-3% O2, 3% CO2, 94-94.5% N2, and nearly 100% RH. Nontreated ‘Delicious’ and ‘Idared’ apples did not respond to low-ethylene CA, except that low-ethylene CA reduced the incidence of storage scaled on ‘Delicious’ apples. Daminozide-treated ‘Delicious’ apples did not respond to low-ethylene CA; the apples being firm after both low-ethylene and normal-ethylene CA storage. The response to low-ethylene CA by daminozide-treated ‘Idared’ apples was a reduced rate of softening of the apples after storage. The daminozide treatment significantly suppressed the ethylene production of both cultivars of apples in simulated low-ethylene CA storage. Chemical names used: butanedioic acid mono(2,2-dimethylhydrazide)(daminozide).
Abstract
‘McIntosh’ apples (Malus domestica Borkh.) from trees field-sprayed with daminozide were kept in unstoppered 19-liter jars in air at 3.3°C for various periods of time before being sealed and exposed to low-ethylene controlled atmosphere (CA). Similar apples were kept in sealed jars with flow-through low-ethylene CA at 20° for various periods of time before being cooled to 3.3°. After the prestorage treatments of delayed establishment of low-ethylene CA storage (delayed CA) or delayed cooling, these apples were stored in the same jars with a flow-through simulated low-ethylene CA (2.5-3% O2, 3% CO2, <1 μl·liter−1 ethylene, 2.2°-3.3°) for 7.5 months. Delayed cooling or delayed CA for one to 4 days had little adverse effect on the keeping quality of the apples. Delayed cooling for 5 days or delayed CA for 5 to 7 days caused slight decreases in fruit firmness and acidity after storage and sometimes caused slight increases in ethylene production of the apples during storage. Delayed cooling for 7 to 11 days or delayed CA for 9 to 11 days often caused significant decreases in firmness and acidity and large increases in ethylene production. The adverse effect of extended periods of delayed cooling was greater than that of delayed CA. Chemical names used: butanedioic acid mono (2,2-dimethylhydrazide) (daminozide).
Abstract
Daminozide (butanedioic acid mono-(2,2-dimethylhydrazide)-treated ‘McIntosh’ apples (Malus domestica Borkh.) harvested at the preclimacteric stage did not soften in 7-½ months of controiled-atmosphere (CA) storage with <1 ppm ethylene in the atmosphere. These apples were satisfactorily firm and of acceptable-to-good quality after storage plus 7 days at 21°C. Apples from all other treatments were softer and had inferior quality. Control fruit harvested at the preclimacteric stage and stored in CA with a low ethylene level (<2.6 ppm) was also slightly firmer than similar fruit stored in CA with high ethylene (10 or 500 ppm). With a high ethylene level (500 ppm) in CA, daminozide-treated fruit was not firmer than control fruit and had more ‘McIntosh’ breakdown during the 7-day holding period after storage.
Abstract
High temperature (40°C) for 2 and 4 days lowered the acidity of 4 cultivars of apples (Malus domestica Borkh.). The preheated fruit was firmer than the control during 2 to 4 weeks of holding at 21°. The treatment also accelerated the loss of chlorophyll from the fruit skin. The soluble solid content of the fruit was not affected. Apples after the heat treatment had a normal respiratory climacteric and normal ethylene production rates. Some feasibility of applying high temperature to improve apple quality seems to exist.
A high CO2 slow cooling CA storage procedure was developed for `McIntosh' apples (Malus domestica Borkh.). The apples were cooled from 18° to 3°C in 15 days in atmospheres containing a constant O2 at 2.5% and decreasing CO2 starting with 12% and ending at 3%. The results of several tests in a flow-through simulated CA storage system revealed that the new procedure was nearly as effective as rapid CA and was much more effective than traditional slow CA in preserving the firmness of `McIntosh' apples for up to 4 months of storage. Maintaining a constant CO2 either at 12% or 3% instead of gradually decreasing it from 12% to 3% during the slow cooling period resulted in more storage disorders or/and softer apples.