scholarly journals Heat Treatment of Mature-green Tomatoes: Differential Effects of Ethylene and Partial Ripening

1998 ◽  
Vol 123 (3) ◽  
pp. 457-462 ◽  
Author(s):  
R.E. McDonald ◽  
T.G. McCollum ◽  
E.A. Baldwin
Keyword(s):  
Heat Treatment ◽  
Chilling Injury ◽  
Internal Quality ◽  
Ripe Fruit ◽  
Free Sterols ◽  
Steryl Esters ◽  
Heat Treated ◽  
Lycopene Content ◽  
Ripe Stage

Mature-green `Sunbeam' tomatoes (Lycopersicon esculentum Mill.) were treated in varying order with C2H4, 42 °C water for 1 hour, 38 °C air for 2days, held 2 days at 20 °C (partial ripening), or not treated and then stored at 2 °C (chilled) for 14 days before ripening at 20 °C. Heat-treated fruit stored at 2 °C and transferred to 20 °C ripened normally, while 63% of nonheated fruit decayed before reaching the red-ripe stage. Partially ripened fruit developed more chilling injury, were firmer, were lighter, and were less red in color than fruit not partially ripened. Lycopene content and internal quality characteristics of fruit were similar at the red-ripe stage irrespective of sequence of C2H4 exposure, heat treatment, or a partial ripening period. Of the 15 flavor volatiles analyzed, 10 were reduced by storage at 2 °C, Exposure to C2H4 before the air heat treatment reduced the levels of four volatiles, while C2H4 application either before or after the water heat treatment had no effect on flavor volatiles. Two volatiles were decreased and two were increased by partial vipening, Storage at 2 °C decreased the level of cholesterol and increased levels of campesterol and isofucosterol in the free sterol pool. Exposure to C2H4 before or following heat treatments, the method of heat treatment, and partial ripening had little effect on free sterols, steryl esters, steryl glycosides, or acylated steryl glycosides in the pericarp of red-ripe fruit. A shortor long-term heat treatment of mature-green tomatoes could permit storage at low temperatures with little loss in their ability to ripen normally, whereas partial ripening did not reduce chilling injury.

scholarly journals Prestorage Heat Treatments Influence Free Sterols and Flavor Volatiles of Tomatoes Stored at Chilling Temperature

1996 ◽  
Vol 121 (3) ◽  
pp. 531-536 ◽  
Author(s):  
R.E. McDonald ◽  
T.G. McCollum ◽  
E.A. Baldwin
Keyword(s):  
Tomato Fruit ◽  
Heat Treatments ◽  
Internal Quality ◽  
Chilling Temperature ◽  
Free Sterols ◽  
Heat Treated ◽  
Short And Long Term ◽  
Lycopene Content ◽  
Ripe Stage

The objective of this study was to determine the effects of prestorage heat treatments on chilling tolerance of tomatoes. Mature-green `Agriset' tomato fruit (Lycopersicon esculentum Mill.), either C2H4-treated or not, were immersed in 42C water for 60 min, held in 38C air for 48 hours, or not treated, and then stored at either 2C (chilled) or 13C (nonchilled) for 14 days before ripening at 20C. Heat-treated fruit stored at 2C and transferred to 20C ripened normally while nonheated fruit decayed before reaching red ripe. Color (a*/b* ratio), lycopene content, and internal quality characteristics of fruit were similar at the red-ripe stage irrespective of method of heat treatment. In red-ripe heat-treated fruit, free sterol levels were significantly higher in chilled fruit than in nonchilled fruit. Heating fruit in 38C air resulted in significantly higher levels of some free sterols compared with heating fruit in 42C water. Of the 15 flavor volatiles analyzed, six showed significantly decreased concentrations as a result of C2H4-treatment and seven showed decreased concentrations when stored at 2C before ripening. Some volatiles were decreased by the heat treatments. Prestorage short- and long-term heat treatments could allow for storage of mature-green tomatoes at lower temperatures with little loss of their ability to ripen normally.

scholarly journals Quality of Tomatoes Stored at Chilling Temperatures following Prestorage Heat Treatments and Partial Ripening

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 642a-642
Author(s):  
R.E. McDonald ◽  
T.G. McCollum ◽  
E.A. Baldwin
Keyword(s):  
Heat Treatment ◽  
Tomato Fruit ◽  
Chilling Injury ◽  
Heat Treatments ◽  
Internal Quality ◽  
Heat Treated ◽  
Chilling Temperatures ◽  
Lycopene Content ◽  
Ripe Stage

Mature green `Sunbeam' tomato fruit (Lycopersicon esculentum Mill.), were treated in varying order with C2H4, 42°C water for 60 minutes, 38°C air for 48 hours, partial ripening for 48 hours at 20°C, or not treated, and then stored at 2°C for 14 days before ripening at 20°C. Heat treated fruit stored at 2°C and transferred to 20°C ripened normally while 63% of nonheated fruit decayed before reaching red ripe. More chilling injury (CI) developed when C2H4 was applied following heat treatment rather than before. There was more CI in fruit that were 42°C water treated compared with the 38°C air treatment. Less CI developed on fruit that were partially ripened for 2 days at 20°C before a 42°C water treatment rather than following it. At red ripe, nonchilled fruit were firmer than chilled heat treated fruit. Fruit treated in 42°C water were firmer when the heat treatment was applied before the C2H4 treatment rather than following it. Chlorophyll and lycopene content and internal quality characteristics of fruit were similar at the red ripe stage irrespective of C2H4 or heat treatment. Chilling and heat treatments reduced some of the 15 flavor volatiles analyzed. Volatile levels were lower in fruit treated with C2H4 before heat treatment compared with fruit treated with C2H4 following heat treatment. Prestorage heat treatments could allow for storage of mature green tomatoes at low temperatures with little loss in their ability to ripen normally.

scholarly journals Heat Treatments Extend Shelf-life of Tomato Fruit

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 786D-786 ◽  
Author(s):  
R.E. McDonald ◽  
T.G. McCollum ◽  
E.A. Baldwin
Keyword(s):  
Heat Treatment ◽  
Tomato Fruit ◽  
Chilling Injury ◽  
Treatment Method ◽  
Heat Treatments ◽  
Internal Quality ◽  
Color Development ◽  
Lycopene Content ◽  
Ripe Stage ◽  
Heat Treatment Method

Mature, green tomatoes were either gassed or not gassed with C2H4 for 24 h, immersed in 42C water for 60 min, or held in 38C air for 48 h or not treated, and then stored at either 2C or 13C for 14 days before ripening at 20C. During ripening, the fruit were evaluated for color development, internal quality, and decay and for volatiles when full ripe. Both high-temperature treatments reduced chilling injury and inhibited decay. Days to ripen after removal from storage at 2C or 13C was not influenced by heat treatment method. Color development, lycopene content, and internal quality characteristics of fruit were similar at the ripe stage, irrespective of heat treatment. Of 15 volatiles analyzed, seven showed decreased levels of concentrations as a result of C2H4 gassing, nine showed decreased levels when stored at 2C prior to ripening, and most were unaffected by the heat treatments. Heat treatments appear to be beneficial for maintaining tomato fruit quality.

scholarly journals Tolerance of Cherimoya (Annona cherimola Mill.) to Cold Storage

1994 ◽  
Vol 119 (3) ◽  
pp. 524-528 ◽  
Author(s):  
Rafael Alique ◽  
José P. Zamorano ◽  
Ma Luisa Calvo ◽  
Carmen Merodio ◽  
José L. De la Plaza
Keyword(s):  
Cold Storage ◽  
Ethylene Production ◽  
Soluble Sugar ◽  
Chilling Injury ◽  
Ethylene Synthesis ◽  
Ripe Fruit ◽  
Acid Accumulation ◽  
Ripe Stage ◽  
Lower Temperature ◽  
Stimulation Of

`Fino de Jete' cherimoya fruit were stored at 20, 10, 8, or 6C, 80% relative humidity. Two rises of CO2 production and an ethylene rise following the first peak of respiration were obtained in fruit held at 20C. The ripe stage coincided with the onset of the second respiratory rise. Soluble sugar and organic acid concentration were maximal, and flesh firmness was 18 N in ripe fruit. Lower temperature reduced respiration rate and ethylene production; however, some stimulation of ethylene synthesis was observed at 10C. Cherimoyas ripened to edible condition during 6 days at 10C, but fruit maintained at 8C for up to 12 days required transfer to 20C to ripen properly. Our results suggest that high increases in CO2 are not sufficient to complete cherimoya fruit ripening without the concurrent rise in ethylene production. Citric acid accumulation, inhibition of ethylene synthesis, and reduced accumulation of sucrose were observed during storage at 6C. Removal to 20C after 12 days at 6C resulted in no ripening, almost complete inhibition of ethylene synthesis, and severe skin browning. Thus, 8C is the lowest tolerable temperature for prolonged cold storage of cherimoya `Fino de Jete'. Fruit can be held at 8C for up to 12 days without damage from chilling injury.

Effect of Double-Step Solution Treatment on Rejuvenation Heat Treated Microstructure of IN-738 Superalloy

2020 ◽  
Vol 856 ◽  
pp. 36-42
Author(s):  
Chuleeporn Paa-Rai
Keyword(s):  
Heat Treatment ◽  
Image Analysis ◽  
Electron Microscope ◽  
Solution Treatment ◽  
Single Step ◽  
Double Step ◽  
Heat Treated ◽  
Cast Superalloy ◽  
Scanning Electron

This work investigates the effect of rejuvenation heat treatment, with double-step solution treatment at the temperature from 1150 °C to 1200 °C, on the recovered microstructure of IN-738 cast superalloy. The superalloy has been long-term exposed as a turbine blade in a gas turbine prior to this study. After double solution treatment and aging at 845 °C for 12 h and 24 h, the recovered microstructures were examined by using a scanning electron microscope. Coarse γ΄ particles, that have presented in damaged microstructures, could not be observed in the samples after the rejuvenation heat treatment. In addition, the image analysis illustrates that the reprecipitated γ΄ particles in the samples with double-step solution treatments increase significantly in sizes during aging than that in the samples with the single-step solution treatment. Furthermore, the measurement of the samples hardness presents that the as-receive sample hardness is improved after rejuvenation heat treatment studied in this work.

scholarly journals Biochemical Bases for Controlled-atmosphere Effects on Reducing Chilling Injury of `Hass' Avocado Fruit

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 809E-809
Author(s):  
Dana F. Faubion ◽  
Adel A. Kader
Keyword(s):  
Fatty Acid ◽  
Chilling Injury ◽  
Controlled Atmosphere ◽  
Ripe Fruit ◽  
Steryl Esters ◽  
Fatty Acid Unsaturation ◽  
Avocado Fruit ◽  
Steryl Glycoside ◽  
Flesh Browning ◽  
Hass Avocado

California-grown `Hass' avocado fruit were stored at 5C, in air or a controlled atmosphere (CA) of 2% oxygen and 5% carbon dioxide. Fruit were evaluated at 0, 2, 4, 6, 8, 10, and 12 weeks, both immediately upon removal from storage and after ripening at 20C. Severe chilling injury (flesh browning) developed in the airstored fruit after 6 weeks, while only moderate symptoms were observed in CA-stored avocado fruit after 12 weeks. Lipid peroxidation breakdown products increased during storage and ripening in both air and CA treatments. Sterols, steryl esters, steryl glycosides, glycolipids, and phospholipids were analyzed. Quantity of acylated steryl glycoside in ripe fruit changed from 34 nmoles initially, to 51 or 27 nmoles after 6 weeks at 5C in air or CA, respectively. Glycolipid fatty acid unsaturation in air-stored fruit decreased with the development of chilling injury. Fatty acid unsaturation in phospholipids (phosphatidylinositol, phosphatidylcholine, phosphatidylglycerol, and phosphatidylethanolamine) of air-stored avocados decreased with the development of chilling injury. CA storage delayed the development of chilling injury and the loss of fatty acid unsaturation.

scholarly journals Changes to Physical Properties of the Cell Wall and Polyuronides in Response to Heat Treatment of `Fuyu' Persimmon that Alleviate Chilling Injury

1997 ◽  
Vol 122 (5) ◽  
pp. 698-702 ◽  
Author(s):  
Allan B. Woolf ◽  
Elspeth A. MacRae ◽  
Karen J. Spooner ◽  
Robert J. Redgwell
Keyword(s):  
Heat Treatment ◽  
Cell Wall ◽  
Molecular Mass ◽  
Chilling Injury ◽  
Heat Treatments ◽  
Wall Material ◽  
Diospyros Kaki ◽  
Average Molecular Mass ◽  
Heat Treated ◽  
Subsequent Degradation

Modifications to solubilized cell wall polyuronides of sweet persimmon (Diospyros kaki L. `Fuyu') were examined during development of chilling injury (CI) during storage and in response to heat treatments that alleviated CI. Storage at 0 °C caused the solubilization of a polyuronide fraction that possessed a higher average molecular mass than polyuronide solubilized during normal ripening. The viscosity of this fraction was 30-times that of normally ripened fruit. Fruit heat-treated before or following storage contained a soluble polyuronide fraction with a markedly lower average molecular mass and decreased viscosity than in chilling injured fruit. Heat treatment also impeded an increase in viscosity of the cell wall material if applied before storage. CI (gelling) was related to the release of polyuronide from the cell wall during storage and its lack of subsequent degradation. Heat treatments retarded polyuronide release but promoted degradation of solubilized polyuronides.

Tensile and Creep Behavior of Ordered Orthorhombic Ti2A1Nb-Based Alloys

1990 ◽  
Vol 213 ◽  
Author(s):  
R.G. Rowe ◽  
D.G. Konitzer ◽  
A.P. Woodfield ◽  
J.C. Chesnutt
Keyword(s):  
Heat Treatment ◽  
Titanium Aluminide ◽  
Room Temperature ◽  
Single Phase ◽  
Two Phase ◽  
Creep Properties ◽  
Specific Strength ◽  
Heat Treated ◽  
Titanium Aluminide Alloys

ABSTRACTTitanium aluminide alloys with compositions near Ti-25A1-25Nb at.% were prepared by both rapid solidification and ingot techniques. Their tensile and creep properties were studied after heat treatment to produce various microstructures containing ordered orthorhombic (O) [1], ordered beta (βo), and α2 phases. It was found that these alloys had higher specific strength from room temperature to 760°C than conventional α2 alloys. Ductility and tensile strength of O+βo alloys were strongly dependent upon heat treatment, with the highest strength observed as-heat-treated, and the highest ductility after long term aging. The creep resistance of single phase O and two phase O+βo alloys was strongly dependent upon heat treatment.

scholarly journals Microstructural Evolution of Large Cast Haynes 282 at Elevated Temperature

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 867
Author(s):  
Yujin Yang
Keyword(s):  
Heat Treatment ◽  
Isothermal Aging ◽  
Power Plants ◽  
Post Heat Treatment ◽  
Sand Cast ◽  
Creep Properties ◽  
Heat Treated ◽  
Heat Treated Condition ◽  
Cast Condition

Haynes 282 has attracted attention for casting applications in AUSC power plants due to its good creep properties. However, the market is primarily comprised of wrought Haynes 282, while the cast version is not commercially available. In this study, the microstructure of a large traditional sand cast Haynes 282 was studied from as-cast condition to long-term heat-treated condition by combining experimental data and thermodynamic calculations. The microstructure of a large cast Haynes 282 includes γ, γ’, two types of MX, M23C6 and µ phases. After standard post heat treatment, µ phases were dissolved and precipitated as M6C. The equilibrium state was achieved after 266 h aging at 788 °C, after which γ’ particles began coarsening. These kept to a spherical morphology; the smallest misfit was found with the γ matrix. Once post heat treatment was finished, MX exhibited little morphology and compositional change during the long-term isothermal aging. Grain boundary is covered by discrete M23C6 and M6C precipitates and this morphology keeps stable during isothermal aging. No presence of the needle µ phase have been found at grain boundaries after 10,000 h aging at 788 °C. All these microstructural features indicated that cast Haynes 282 could have a high thermal stability and good creep properties.

Effects of Heat Treatment on the Microstructure of a Fully Simulated Nuclear Waste Glass

1990 ◽  
Vol 212 ◽  
Author(s):  
Terese V. Palmiter ◽  
I. Joseph ◽  
L. David Pye
Keyword(s):  
Heat Treatment ◽  
Nuclear Waste ◽  
Scanning Transmission Electron Microscopy ◽  
Waste Glass ◽  
Amorphous Phases ◽  
Transmission Electron ◽  
Heat Treated ◽  
Nuclear Waste Glass ◽  
Scanning Transmission

ABSTRACTSamples of a fully simulated nuclear waste glass under consideration for use in the West Valley Demonstration Project were isothermally heat treated and studied by scanning transmission electron microscopy (STEM). Both fully oxidized and partially reduced specimens were heat treated for 3 hours at 600°C, 700°C, 800°C and 900°C and for 45 days at 10°C above Tg (447°C -461°C) and at 10°C below TB (427°C -441°C). Microstructural features in untreated as well as the heat-treated glasses were studied using STEM. Analysis by energy dispersive spectroscopy (EDS) was used to identify the elemental compositions of the features observed.The predominant crystalline phase present in the samples heat treated for 3 hours was an Fe3O4 type spinel with Ni and Cr substituting for some of the Fe. The spinels varied in size from 0.02 to 10.0 µm, the larger crystals present at higher heat-treatment temperatures. Long term heat treatment above Tg resulted in the formation of small iron-containing crystals ranging in size from 10 to 35 nm. Heat treatment below Tg produced no crystalline or amorphous phases.

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