THE EFFECT OF TEMPERATURE ON POSTHARVEST PHYSIOLOGY AND STORAGE LIFE OF PEARS

1964 ◽  
Vol 44 (6) ◽  
pp. 568-579 ◽  
Author(s):  
S. W. Porritt
Keyword(s):  
Carbon Dioxide ◽  
Physical Properties ◽  
Metabolic Activity ◽  
Cold Storage ◽  
Storage Life ◽  
Effect Of Temperature ◽  
Periodic Evaluation ◽  
And Storage ◽  
Storage Temperatures ◽  
Temperature Storage

Response of Anjou and Bartlett pears to nine storage temperatures ranging from 29° to 70°F was determined by periodic evaluation of ripened fruit, analysis of certain chemical and physical properties, and measurement of respiration throughout the storage period.After harvest, low metabolic activity persisted about 4 days in Bartlett and over 50 days in Anjou at 50° to 70°F. Anjou pears ripened only after a period of cold storage. The total amount of carbon dioxide respired during storage life diminished with rising temperature. Storage life of Anjou and Bartlett pears was respectively 35 and 40% greater at 30° than at 32°F.

scholarly journals Effect of Temperature and Time Storage to pH and Color Changes of Palm Sap (Arenga pinnata Merr) after Tapping

2019 ◽  
Vol 8 (1) ◽  
pp. 40
Author(s):  
Ansar Ansar ANSAR
Keyword(s):  
Storage Time ◽  
Effect Of Temperature ◽  
Color Changes ◽  
Quality Degradation ◽  
Environment Temperature ◽  
Higher Temperature ◽  
Ph Decrease ◽  
And Storage ◽  
Storage Temperatures ◽  
Temperature Storage

Flos masculus at palm can be produced a palm sap after tapping process. Palm sap have quality degradation due to effect environment temperature. The purpose of the study was to evaluate the effect of temperature and storage time to changes pH and color of palm sap after tapping. The research samples were obtained from farmers in Pusuk, West Lombok, NTB. The research parameters were observed is changes pH and color of palm sap during storage. The sample of the research was storaged at temperature variation of 10, 29, and 40oC, and then observed each 2 until 10 hour. The results of the research showed the temperature and time storage was affected to pH and color palm sap after tapping. After 10 hour pH of palm sap changed from 7.0 to 2.6 at temperature of 40oC, 4.8 at temperature of 29oC, and 6.6 at temperature of 10oC. Palm sap which storage at temperature 10oC has pH quality decrease is lowest than at temperature of 29 and 40oC. The higher temperature storage, the bigger pH decrease. The pH decreases, the L* and b* values also decrease significantly, but the value of a* does not change significantly at various storage temperatures. 

scholarly journals Effects of Delays between Harvest and 1-Methylcyclopropene Treatment, and Temperature during Treatment, on Ripening of Air-stored and Controlled-atmosphere-stored Apples

HortScience ◽  
2005 ◽  
Vol 40 (7) ◽  
pp. 2096-2101 ◽  
Author(s):  
Christopher B. Watkins ◽  
Jacqueline F. Nock
Keyword(s):  
Cold Storage ◽  
Treatment Delay ◽  
Effect Of Temperature ◽  
Controlled Atmosphere ◽  
Malus Sylvestris ◽  
Effects Of Temperature ◽  
Storage Type ◽  
Storage Temperatures ◽  
Efficacy Of Treatment

The effects of temperature during 1-MCP treatment, and the effects of delays of up to 8 d after harvest before treatment, have been investigated using `Cortland', `Delicious', `Jonagold', and `Empire' (normal and late harvest) apple [(Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] cultivars stored in air for 2 and 4 months and in controlled atmosphere (CA) storage for 4 and 8 months. Fruit were treated with 1 μL·L–1 1-MCP for 24 hours on the day of harvest (warm) or after 1, 2, 3, 4, 6, or 8 days at cold storage temperatures. CA storage was established by day 10. Little effect of temperature during treatment (warm fruit on the day of harvest compared with cold fruit after 24 hours of cooling) was detected. Major interactions among cultivars, handling protocols before 1-MCP treatment, storage type and length of storage were observed. Delays of up to 8 days before 1-MCP treatment either did not affect efficacy of treatment, or markedly reduced it, depending on cultivar, storage type and length of storage. The results indicate that, depending on cultivar, the importance of minimizing the treatment delay increases as storage periods increase.

Postharvest treatment.

2021 ◽  
Author(s):  
Ron Wills
Keyword(s):  
Carbon Dioxide ◽  
Respiration Rate ◽  
Metabolic Activity ◽  
Storage Life ◽  
Fruit And Vegetables ◽  
Respiratory Pattern ◽  
Climacteric Fruit ◽  
Physiology And Biochemistry ◽  
Postharvest Treatment ◽  
Cellular Integrity

Abstract Need for postharvest treatment: Fruit and vegetables are unique among food groups in being living biological systems throughout the postharvest chain from farm to consumer. Since harvested produce are removed from the source of nutrients and moisture supplied by the parent plant, they can only maintain full metabolic activity from existing reserves of metabolites. Over time, reduced availability of key metabolites will result in an imbalance in metabolism which often manifests as loss of cellular integrity. A consequence of this loss of integrity is increased leakage of metabolites from cellular compartments. The mixing of previously separated metabolites and enzymes can enhance the production of compounds that further accelerate cellular disruption. The overall process is known as senescence, which is analogous to the ageing process. In addition, the leakage of nutrients and reduced cellular integrity provide ideal conditions for microbial spores present on the surface of produce to germinate and invade internal tissues. This microbial growth, primarily of fungi but also some bacteria, can rapidly manifest as a rot which renders produce unsaleable. Fruit and vegetables used to be marketed soon after harvest and the senescence process was not a great concern. With growing affluence and greater ease of transportation, the consumer has come to expect produce to be available well beyond the normal harvest period, and to purchase commodities that are grown in distant countries or regions within a country. Many produce are now available 12 months of the year. To meet these expectations the quality of many produce needs to be maintained for long periods. Due to the limited supply of metabolites, extended storage is only possible if the rate of metabolism, and hence the rate of utilisation of reserves, is reduced. A range of postharvest technologies that minimise the rate of metabolism of fruit and vegetables and hence extend storage life have been developed. However, some understanding of factors involved in the underlying physiology and biochemistry is needed to appreciate how the developed technologies are effective. Respiration and ethylene: The respiration rate is a good indicator of metabolic activity of fruit and vegetables and is a useful guide to the potential storage life of produce - a higher respiration rate indicates a lower storage life. Respiration involves the oxidative breakdown of the more complex materials such as starch, sugars and organic acids into simpler molecules such as carbon dioxide and water, with the concurrent production of energy and other molecules which are used by the cell for synthetic reactions. The respiration rate is measured as either oxygen consumed or carbon dioxide evolved. It is axiomatic that any technology that reduces the respiration rate will extend storage life. Ethylene is produced by all plants and is involved in the regulation of all stages of plant growth from seed germination to plant senescence. Postharvest fruit and vegetables are sensitive to very low concentrations of ethylene (nL/L range) which accelerate ripening and enhance senescence. Exogenous ethylene generated by other produce in the same storage container or from the exhaust of internal combustion motors is readily absorbed into produce. Hence, it is the absolute concentration of ethylene in the atmosphere around produce that determines the metabolic impact on it. Climacteric and non-climacteric produce: An important classification of fruit and vegetables is those that exhibit either a climacteric or non-climacteric pattern of physiology and biochemistry. Climacteric produce are fruits that exhibit a marked increase in respiration coincident with the ripening process. The increase in respiration rate reaches a maximum value at some time during ripening and the peak value is called the respiratory climacteric. It is during the climacteric period that all the other changes characteristic of fruit ripening such as colour, taste and texture occur. Climacteric fruits include those that undergo marked changes in colour, texture and taste such as mango, banana, apple, pawpaw and kiwifruit, as well as produce such as tomato which are consumed as a vegetable but are botanically fruits. As might be expected, fruits that do not exhibit a respiratory climacteric are known as non-climacteric produce - this group includes citrus fruits, pineapple and strawberry. They, however, do undergo a ripening phase, albeit more slowly than the climacteric fruit. All vegetables have a non-climacteric type of respiratory pattern. Climacteric and non-climacteric fruits are also differentiated by their response to ethylene. During ripening, climacteric fruits produce much larger amounts of ethylene than non-climacteric fruits. They also show a differing response to applied ethylene. Ethylene applied at a low concentration (e.g. 0.1 μL/L) for one day is sufficient to initiate full ripening of climacteric fruit, whereas applied ethylene only causes a transient increase in the respiration of non-climacteric produce. Moreover, the rise in respiration in response to ethylene may occur more than once in non-climacteric produce in contrast to a single respiration increase in climacteric fruits.

scholarly journals Ripening and quality of 'Laetitia' plums following harvest and cold storage as affected by inhibition of ethylene action

2003 ◽  
Vol 38 (10) ◽  
pp. 1139-1148 ◽  
Author(s):  
Luiz Carlos Argenta ◽  
Juliana Golin Krammes ◽  
Clarice Aparecida Megguer ◽  
Cassandro Vidal Talamini Amarante ◽  
James Mattheis
Keyword(s):  
Cold Storage ◽  
Skin Color ◽  
Titratable Acidity ◽  
Storage Life ◽  
Soluble Solids ◽  
Storage Duration ◽  
Ethylene Action ◽  
Solids Content ◽  
And Storage

The inhibition of ethylene action by 1-methylcyclopropene (1-MCP) extends shelf and storage life of many climacteric fruits. However, 1-MCP appears to have limited effects on stone fruit depending on specie and cultivar. The effects of 1-MCP on ripening and quality of 'Laetitia' plums were determined during ripening at 23ºC following harvest and cold storage. Japanese plums (Prunus salicina, cv. Laetitia) were harvested at mature pre-climacteric stage, cooled to 2ºC within 36 hours of harvest and then treated with 0, 0.05, 0.10, 0.50 or 1.00 muL L-1 of 1-MCP at 1°C for 24 hours. Following treatment, fruits were either held at 23ºC for 16 days or stored at 1ºC for 50 days. Fruits were removed from cold storage at 10-day intervals and allowed to ripe at 23°C for five days. A delay of climacteric respiration and ethylene production by 1-MCP treatment during ripening following harvest and cold storage was associated to a slow rate of fruit softening. 1-MCP treatment also delayed the loss of titratable acidity and changes of flesh and skin color, whereas it had little or no effect on soluble solids content. 1-MCP effects were concentration- and storage duration-dependent and, generally, a saturation fruit response to 1-MCP occurred between 0.5 and 1.0 muL L-1. During ripening, 1-MCP treated fruits attained quality similar to that of controls. Results indicated that 1-MCP treatment may extend shelf life (23ºC) and storage life (1ºC) of 'Laetitia' plums by approximately six and 20 days, respectively.

Titer Compounding of Neoprene Latex

1954 ◽  
Vol 27 (1) ◽  
pp. 277-285 ◽  
Author(s):  
G. S. Cook ◽  
J. C. Fitch
Keyword(s):  
Physical Properties ◽  
Practical Importance ◽  
Storage Life ◽  
Free Alkali ◽  
Alkali Content ◽  
Ph Measurements ◽  
Viscosity Increase ◽  
Processing And Storage ◽  
And Storage

Abstract The practical importance of free alkali content on the processing and storage life of Neoprene latexes, both raw and compounded, is demonstrated. It is shown that titer measurements are more sensitive than pH measurements for establishing the alkali level of Neoprene latex, that increasing amounts of alkali increase markedly the life of both raw and compounded latexes, that increasing amounts of alkali decrease the original viscosity of compounds and reduce very much the viscosity increase which takes place during aging but, that, within the ranges checked, the alkali content has little effect on the physical properties of films. A procedure for measuring accurately and adjusting easily the free alkali content of raw latex to a desired level is suggested.

scholarly journals Optimizing Walnut Storage Conditions: Effects of Relative Humidity, Temperature, and Shelling on Quality after Storage

HortScience ◽  
2021 ◽  
pp. 1-9
Author(s):  
Claire Adkison ◽  
Kelly Richmond ◽  
Nico Lingga ◽  
Veronique Bikoba ◽  
Elizabeth Mitcham
Keyword(s):  
Relative Humidity ◽  
Storage Conditions ◽  
Low Temperature Storage ◽  
Quality Degradation ◽  
Shell Temperature ◽  
Effects Of Temperature ◽  
The Relationship ◽  
And Storage ◽  
Storage Temperatures ◽  
Temperature Storage

With increasing walnut production in California, walnuts are stored for longer times. It is increasingly important to optimize storage conditions, wherever possible, to reduce quality degradation. We examined the effects of temperature (5, 15, and 25 °C) and relative humidity (20%, 40%, and 60% in year 1 and 40%, 60%, and 80% in year 2) on the rate of quality degradation of four walnut varieties. The relationship between water activity and moisture content was investigated for each variety. In addition, the effects of harvest timing (early vs. late) and storage as shelled or in-shell product were investigated. Later harvested walnuts had darker kernel color (P < 0.001), and walnuts stored as kernels (shelled) had higher rates of peroxide formation and free fatty acid development than walnuts stored in-shell. Temperature had a significant effect on quality with faster degradation at higher temperatures. There was a significant interaction between temperature and relative humidity effects on quality. The effects of relative humidity were often not significant at storage temperatures of 5 °C but were apparent at 15 °C and at 25 °C. Managing relative humidity during walnut storage is difficult under typical commercial storage conditions; however, when low temperature storage is used, quality is preserved even when relative humidity is not controlled, although storage at 80% relative humidity should be avoided. To reduce the rate of color darkening and rancidity development during commercial storage, operators should emphasize storage at lower temperatures, at least below 15 °C.

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