scholarly journals Controlling Relative Humidity in Modified Atmosphere Packages of Tomato Fruit

HortScience ◽  
1992 ◽  
Vol 27 (4) ◽  
pp. 336-339 ◽  
Author(s):  
Ahmad Shirazi ◽  
Arthur C. Cameron

The feasibility of controlling relative humidity in modified atmosphere packages using compounds possessing Type III sorption isotherm behavior was studied. Ten grams each of dry sorbitol, xylitol, NaCl, KCl, or CaCl2 sealed with one maturegreen tomato (Lycopersicon esculentum L.) fruit at 20C in simulated packages for 48 days resulted in stable relative humidities of ≈75%, 80%, 75%, 85%, and 35%, respectively. Relative humidity was a function of the ratio of chemical to fruit mass. Relative humidities within control packages were in the range of 96% to 100% throughout the experiments. A simple system that uses spunbonded polyethylene pouches for the application of this humidity control method to packages is described. The storage life of packaged red-ripe tomato fruit at 20C was extended from 5 days using no pouch to 15 to 17 days with a pouch containing NaCl, mainly by retardation of surface mold development.

Author(s):  
Elena Yuryevna Porotikova ◽  
Boris Lazarevich Nekhamkin ◽  
Mikhail Pavlovich Andreev

The present article investigates the effect of sodium lactate on microbiological, physico-chemical and sensory characteristics of lightly salted Pacific herring ( Clupea pallasii ) and Baltic herring ( Clupea harengus membras ) during refrigerated storage 5 ± 0.3°C. There have been analyzed different processing methods of lightly salted samples of Pacific and Baltic herring: control (without sodium lactate), and experiment (3% sodium lactate), both in vacuum packaging and modified atmosphere packaging (MAP - 40% CO2/60% N2). For vacuum and MAP there were used bags with low oxygen permeability (3 cm3/m2/day). It was found that 3% sodium lactate keeps firmness of the texture of salted fish muscle and reduces the release of water into the package during storage. Adding 3% sodium lactate reduces the value of the water activity in lightly salted Pacific and Baltic herring by 0.01-0,012 units. The lowest pH (0.02 units) was registered in samples without sodium lactate packed in MAP. Organoleptic signs of spoilage in fish without sodium lactate appeared much earlier, and using 3% sodium lactate both in vacuum and in MAP helped protect and improve organoleptic characteristics of the product during storage. Total biological semination of experimental samples packed in MAP kept at the very low level during the whole storage period, i.e. combined effect of using 3% sodium lactate and MAP inhibited microbial growth. This combination allows to reduce twice the rate of accumulation nitrogen in terminal amino-groups and to increase 1.5-2 times storage life of lightly salted Pacific and Baltic herring, compared to their storage life in vacuum packaging without sodium lactate. The results obtained allow us to recommend using sodium lactate in production of lightly salted fish in oxygen-free packaging, especially in modified atmosphere packaging (40% CO2/60% N2).


1985 ◽  
Vol 65 (4) ◽  
pp. 1011-1018 ◽  
Author(s):  
C. S. TAN ◽  
B. N. DHANVANTARI

Two tomato (Lycopersicon esculentum Mill.) cultivars, Heinz-2653 and Campbell-28, were grown on Fox loamy sand in the subhumid region of southern Ontario from 1979 to 1982. Irrigation increased the marketable yields of H-2653 in a dry year, 1982, but not in the other years. Irrigation substantially increased marketable yields of C-28 in 1979 and 1982. Irrigation, when the available soil moisture (ASM) level reached 50%, was no more effective than when the ASM level in the soil was allowed to drop to 25%. Without irrigation yield increased as plant population increased in normal and wet years, but not in a dry year. Blossom-end rot (BER) of C-28 cultivar was markedly reduced by irrigation. Effects of irrigation or plant population treatments on the incidence of fruit speck did not appear to be significant.Key words: Available soil moisture, Lycopersicon esculentum, Pseudomonas syringae pv. tomato, fruit speck


1990 ◽  
Vol 2 (4) ◽  
pp. 243-254 ◽  
Author(s):  
Mandy J. Hetherington ◽  
Alan Martin ◽  
Douglas B. MacDougall ◽  
Keith R. Langley ◽  
Nick Bratchell

2016 ◽  
Vol 9 ◽  
pp. 10007 ◽  
Author(s):  
Vasileios Mantikos ◽  
Steven Ackerley ◽  
Andrew Kirkham ◽  
Aikaterini Tsiampousi ◽  
David M.G. Taborda ◽  
...  

2016 ◽  
Author(s):  
Michael G. Bowler ◽  
David R. Bowler ◽  
Matthew W. Bowler

AbstractThe humidity surrounding a sample is an important variable in scientific experiments. Biological samples in particular require not just a humid atmosphere but often a relative humidity (RH) that is in equilibrium with a stabilizing solution required to maintain the sample in the same state during measurements. The controlled dehydration of macromolecular crystals can lead to significant increases in crystal order, which often leads to higher diffraction quality. Devices that can accurately control the humidity surrounding crystals on a beamline have led to this technique being increasingly adopted, as experiments become easier and more reproducible. Matching the relative humidity to the mother liquor is the first step to allow the stable mounting of a crystal. In previous work, we measured the equilibrium relative humidity for a range of concentrations of the most commonly used precipitants and showed how this related to Raoult’s law for the equilibrium vapour pressure of water above a solution. However, a discrepancy between measured values and those predicted by theory could not be explained. Here, we have used a more precise humidity control device to determine equilibrium relative humidity points. The new results are in agreement with Raoult’s law. We also present a simple argument in statistical mechanics demonstrating that the saturated vapour pressure of a solvent is proportional to its mole fraction in an ideal solution: Raoult’s Law. The same argument can be extended to the case where solvent and solute molecules are of different size, as is the case with polymers. The results provide a framework for the correct maintenance of the RH surrounding samples.SynopsisThe equilibrium relative humidity values for a number of the most commonly used precipitants in biological macromolecule crystallisation have been measured using a new humidity control device. A simple argument in statistical mechanics demonstrates that the saturated vapour pressure of a solvent is proportional to its mole fraction in an ideal solution (Raoult’s Law). The same argument can be extended to the case where solvent and solute molecules are of different size.


2006 ◽  
Vol 42 (3) ◽  
pp. 228-234 ◽  
Author(s):  
Patrícia Cia ◽  
Eliane A. Benato ◽  
José M.M. Sigrist ◽  
Claire Sarantopóulos ◽  
Léa M. Oliveira ◽  
...  

1975 ◽  
Vol 55 (2) ◽  
pp. 597-604
Author(s):  
W. R. ALLEN ◽  
K. C. CHADHA

A severe fruit disorder of tomato (Lycopersicon esculentum Mill.) was induced with a tobacco form of tobacco mosaic virus isolated from blemished tomato fruit (cv. Ohio WR25) from a glasshouse crop in southwestern Ontario. Symptoms on green tomatoes consisted of slightly sunken, pale or yellowish-brown lesions with a thin, dark green margin. Lesions frequently expanded and coalesced along the flutes. The shoulders of the fruit were the most extensively affected areas. On mature fruit, the lesions appeared either silvery or silvery-brown and generally had a scabby appearance due to cracking and lifting of the surface tissues. Lesions were superficial and internal symptoms were not detected. First-truss inoculations prevented or delayed the fruit disorder. Inoculations at truss stages two, three, and four, however, resulted in development of affected fruit on inoculated as well as lower and subsequent trusses with the exception of the first truss. Similar susceptibilities to the fruit disorder occurred among the glasshouse cultivars Michigan Ohio (Burghart strain), Ohio WR25, Vantage, Veegan, and Vendor. No cross protection against the fruit disorder was provided by a mild tomato form of TMV introduced at the second-leaf stage.


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