Storage Of Pears Research Articles

Changes in mRNA during low temperature storage and ripening of pears

A method is described for the purification of nucleic acid from conference pear fruit. RNA was extracted from preclimacteric pears prior to storage, 60 days after storage at −1° and during the early stages of post storage ripening. In vitro translation of this RNA indicated that it was intact and showed a number of mRNA changes were occurring during both storage and subsequent ripening. Notable was the accumulation during storage of mRNAs coding for polypeptides with M r of ca 38, 44 and 45 000, and during the first 48 hr out of store a mRNA coding for a polypeptide with an M r of ca 43 000. The results show that low temperature storage and subsequent ripening of conference pears are accompanied by altered gene expression.

Radiation preservation of foods of plant origin. Part V. Temperate fruits: Pome fruits, stone fruits, and berries

The current status of research on the application of ionizing radiation for improving the storage of temperate fruits, i.e., apple, pear, peach, nectarine, apricot, cherry, plum, strawberry, bilberry, cranberry, raspberry, and black currant, is reviewed. Changes in fruit metabolism, chemical composition, texture, and organoleptic quality attributes are discussed with reference to the irradiation dose. The feasibility of using radiation either alone or in conjunction with heat treatment, refrigeration, and controlled atmospheres (CA) for the control of storage decay caused by fungal pathogens is considered. Areas of further research are suggested before irradiation could be considered for practical application in some of these temperate fruits. The recent trends in the possible use of irradiation for disinfestation of certain pome and stone fruits and the prospects for the commercial utilization of irradiation for improving the market life of strawberries are discussed.

The effects of preharvest factors on the quality of stored Conference pears I. Effects of orchard factors

SummaryThe influence of orchard factors on the storage potential and quality of Conference pear fruits from five sites in England and. Belgium was investigated in two successive seasons. Belgian fruits were generally larger, had higher soluble solids in the second year and lost less moisture during storage for up to 44 weeks at – 1°C in air. Belgian fruits were slightly less mature when harvested, taking longer to reach the pre-climacteric minimum at 12°C. No differences were found in firmness ex-store between sites from the same country of origin in 1978; however, Belgian fruits were generally softer. In the following year evidence was obtained of an orchard factor effect on fruit firmness in fruit from both countries. Fruits were generally softer in 1979 compared to 1978. During storage little change occurred in firmness between 26 and 34 weeks. However, the fruit from all sites had softened significantly by the 44th week. The pattern of fruit ripening after storage generally appeared to be influenced b...

Changes in Phenolic Acids and Internal Ethylene during Long-term Cold Storage of Pears

Abstract High performance liquid chromatography of mature ‘Beurre d'Anjou’ and ‘Beurre Bosc’ pear (Pyrus communis L.) fruit flesh showed that the major phenolics at harvest were chlorogenic acid, catechin, and arbutin. Neither cultivar contained epicatechin nor p-coumaroyl quinate. During 160 days at –1°C the chlorogenic acid content of d'Anjou increased significantly. In ‘Bosc’, chlorogenic acid levels decreased during storage. Catechin content increased linearly while arbutin levels remained nearly constant in both cultivars. Coincident with the completion of the cold requirement for initiation of ripening and endogenous ethylene production, i.e., 20 days for ‘Bosc’ and 50 days for ‘d'Anjou’, there was an appearance of low levels of a p-coumaric acid derivative and trace amounts of epicatechin/p-coumaroyl quinate. At 120 days epicatechin/p-coumaroyl quinate increased in ‘d'Anjou’ but not in ‘Bosc’. There is a coincidence, and perhaps relationship, between ethylene production and the quantity as well as the composition of phenolics present during storage. Bruising pear fruit after 120 days of storage caused a 30% increase in chlorogenic acid and a 50% increase in catechin, but no increase in p-coumaric acid derivatives.

Night cooling for storage of pears and persimmons in northern Thailand

SYNOPSIS The roof-pond night-cooling technique was investigated for possible use in storage of fruits grown in northern Thailand. A 3 x 3.5 X 2 m experimental test room was constructed and monitored over a one-year period. Two varieties of pear and one variety of persimmon were stored in the cool room during 1983. Results showed that room temperature varied between 9–17°C, and room relative humidity ranged from 85–90%, during the period tested. With 50% good fruits still remaining, the Pien Pu variety of pear could be stored in the cool 'room for 35 days (under normal pressure) and 99 days (under 160 mmHg pressure), compared with 10 days at normal room temperature. The New Century variety of pear could be stored in the cool room for 42 days, compared with 7–10 days at room temperature. For P-1 persimmon, storage in the cool room extended the fruit's life to 119 days (under 160 mmHg pressure), compared to 7 days at normal room temperature, and 7 days in the cool room at normal pressure. These results indic...

The controlled atmosphere storage of Conference pears

SummaryConference pears from five sources in Kent were stored in 0.5%, 1% and 2% O2 at — 1°C. Samples from one source were also stored in air at the same temperature. On ripening at 18°C in air there was a lag phase before softening commenced. The lag phase generally lasted 3 d for fruit from 0.5% O2 storage, 2 d for fruit from 1% and 2% O2 storage, and between 1 and 3 d for fruit from air storage. There was no lag phase before chlorophyll loss. The rate of decline of firmness at 18°C was higher for fruit from 0.5% O2 storage than for fruit from 1% or 2% O2 storage. There was no effect of source of fruit on the length of the lag phase or the rate of softening. It was concluded that the storage life of Conference pears at — 1°C was at least 40 weeks in 0.5%, 1% or 2% O2 and 35 weeks in air.

VARIATION OF SUGARS AND ACIDS DURING RIPENING OF PEARS AND IN THE PRODUCTION AND STORAGE OF PEAR CONCENTRATE

ABSTRACTMajor sugars (fructose, sorbitol, glucose, and sucrose) and acids (malic, citric, phosphoric, and quinic) of pears were isolated by ion exchange and quantitated by gas chromatography (Cc) of their trimethylsilyl derivatives (TMS) during ripening and in the production and storage of pear concentrate. Ripening pears attained maximum sugar content (13.5%) and acidity (6 meq) at a flesh firmness of 6 lb. Apart from a small loss of sucrose at depectinization and concentration stages little change occurred during pear concentrate production. Accelerated storage (16 wk, 36°C) of the concentrate resulted in brown color development and 6% sugar loss. Sucrose hydrolysis and Maillard browning of reducing sugar account for this sugar loss.

The Biology of Apple and Pear Storage

The Biology of Apple and Pear Storage

Sensitivity to gamma irradiation of fungi pathogenic to pears

The effect of gamma irradiation at doses of 50–300 krad, on the germination ability of fungi in vitro, and prolongation of the incubation period in vivo, was studied with known spore populations of four fungi pathogenic to stored pears. Rot development and fungal control were examined in cold storage after irradiation of fruit inoculated with two radio-sensitive fungi. Inhibition of spore germination was found to be directly correlated to the strength of the radiation dose and indirectly correlated to the spore concentration. Penicillium expansum was the most sensitive to radiation both in culture and in fruit tissues. Some prolongation of the incubation period of P. expansum and of Botrytis cinerea, the two principal pathogens, occured after irradiation with 100 krad. With increasing dosage, the incubation period was more prolonged and staggered and the percentage of infected fruit began to decrease from 200 krad. Alternaria tenuis and Stemphylium botryosum were radiation-resistant. In spite of a decrease in germination ability at the higher doses, the pathogenicity and incubation period of both these fungi were not significantly affected.

Studies on the practical use of one year stored pear pollens in the Nijisseiki pear culture

The possibility of practical use of one year stored pear pollens for the artificial pollination of Nijisseiki pear was investigated in 1962-1965.1. At the optimum storage condition in a home use electric refrigerator one year stored pear pollens of three varieties gave a germination of 80.3% for Chojuro, 67.4% for Okusankichi, and 85.0% for Yagumo, respectively. They were 5-10% lower than the germination rate of freshly collected pollens in the respective varieties.2. As the result of artificial pollination of stored pollens in the field, more than 80% of the flowers developed into fruit having average 7 seeds per fruit when the pollens had more than 30% of germination rate. Also, there found no differences between stored and freshly collected pollens in the rate of fruit set, fruit development, and quality after harvest. It seemd that there was no trouble to use one year stored pollens in practical Nijisseiki pear culture.3. It was recognizied that one year stored pollens collected from vigorous tree gave a germination of more than 70% when they were put into the refrigerator within 24 hours after collected and were kept at 5°C and 30-50% relative humidity.

Fruit Storage, Storage of Pears and Apples in the Presence of Ripened Fruit

Fruit Storage, Storage of Pears and Apples in the Presence of Ripened Fruit

Experiments on the Storage of Pears in Artificial Atmospheres.: II. Subnormal Oxygen Atmospheres with and Without the Addition of Carbon Dioxide.

Experiments on the Storage of Pears in Artificial Atmospheres.: II. Subnormal Oxygen Atmospheres with and Without the Addition of Carbon Dioxide.

Experiments on the Storage of Pears in Artificial Atmospheres.

Experiments on the Storage of Pears in Artificial Atmospheres.