Low Temperature Injury to Fruits and Vegetables

1968 ◽  
pp. 271-283 ◽  
Author(s):  
J.C. FIDLER
Keyword(s):  
Low Temperature ◽  
Fruits And Vegetables

scholarly journals A Novel Transportation Method Based on Dynamic Control of Ripening Environment

2020 ◽  
Vol 13 (5) ◽  
pp. 58-66
Author(s):  
Xinyu Liu ◽  
◽  
Xiaojie Jin
Keyword(s):  
Low Temperature ◽  
Fruits And Vegetables ◽  
Control Method ◽  
Volume Fraction ◽  
Dynamic Control ◽  
Exogenous Ethylene ◽  
Quality Of Products ◽  
And Control ◽  
Air Circulation

The dynamic control of atmosphere is an important factor for guaranteeing the quality of climacteric products during transportation. As atmosphere changes, respiration climacteric products would rot because of overripeness, thus leading to loss. Moreover, climacteric products must be ripened artificially when delivered to the destination, thereby causing economic waste. In this study, a new transportation method based on dynamic control of ripening environment was designed.The ripeness control method based on the dynamic control of ripening atmosphere was presented to accomplish quality safety during transportation as well as avoid a subsequent extra process of ripening. The transportation method was employed to stem from the ethylene’s ripening effect on climacteric fruits and vegetables. The ethylene generator and air circulation unit, which dynamically regulate and control the dual regional atmosphere of carriages during transportation, were quantitatively controlled by the central treatment layer. Ripeness level could be regulated by controlling the temperatures and time of exogenous ethylene release, to control the quality of products and ripen them. The proposed method was proven feasible through experiments. Results demonstrate that a volume fraction of 0.01% exogenous ethylene allows bananas’ respiratory intensity to reach the peak early; meanwhile, moderate low temperature (16 °C) can enable ethylene peak to appear in advance. Therefore, bananas’ ripeness can be controlled by changing temperatures and the ripening environment when transporting. This study can provide references for the control of products’ ripeness during transportation.

CONTROLLED ATMOSPHERIC ENVIRONMENTS AND THEIR EFFECTS ON APHIDS AND WESTERN FLOWER THRIPS ON FLORAL PRODUCTS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 554g-555
Author(s):  
Virginia R. Walter ◽  
Mark D. Shelton ◽  
Richard A. Cavaletto
Keyword(s):  
Relative Humidity ◽  
Low Temperature ◽  
Methyl Bromide ◽  
Fruits And Vegetables ◽  
Western Flower Thrips ◽  
Pacific Rim ◽  
Insect Control ◽  
Controlled Atmosphere ◽  
Preliminary Results ◽  
Flower Thrips

Shipments of floral products to Pacific rim markets must meet stringent pest-free requirements. Conventional fumigation methods with methyl bromide will soon become unavailable. Studies show that controlled atmosphere (CA) environments can offer effective insect control. Currently, CA overseas marine shipping is occuring with fresh fruits and vegetables. These shipments use microprocessors to precisely control O2, CO2, temperature and relative humidity. This study is evaluating similar commercial shipments with fresh flowers and foliage under low temperature and low O2 and high CO2 atmospheres. Preliminary results with shipments conducted by TransFresh to Guam indicate that properly maintained CA shipments of 0.5 % O2 kill insects and that flowers in properly maintained atmospheres can withstand 14 days of marine shipment with minimum effect on post-harvest life. Adequate regulation of CA storage during transit seems to be the primary limitation to the expansion of floral markets using this method of shipment.

scholarly journals Physiology of fruit.— I. Changes in the respiratory activity of apples during their senescence at different temperatures

1930 ◽  
Vol 106 (742) ◽  
pp. 93-109 ◽  
Keyword(s):  
Low Temperature ◽  
Fruits And Vegetables ◽  
Respiratory Activity ◽  
Plant Tissues ◽  
Research Station ◽  
Living Plant ◽  
Economic Background ◽  
Different Temperatures ◽  
Long Storage

For some years there has been in progress, at the Low Temperature Research Station at Cambridge, a series of researches dealing with the influence of important variables upon the metabolism of plant tissues and organs. These variables are race, age, nutrition and temperature. While these researches are academic in character, they have been planned to explore a field of enquiry in which an advance in our knowledge of general principles appears likely to assist industrial progress. The economic background in the present instance is to be found in modern necessities for the long storage and transport of living plant tissues—the fruits and vegetables of commerce—for consumption as food.

scholarly journals Determination of color formation of multicomponent fruit and vegetable pastes and dried powder fractions during low temperature treatment

2021 ◽  
pp. 43-48
Author(s):  
Aleksey Zagorulko ◽  
Andrii Zahorulko ◽  
Mariana Bondar ◽  
Alexander Postadzhiev ◽  
Eldar Ibaiev
Keyword(s):  
Low Temperature ◽  
Fruits And Vegetables ◽  
Raw Materials ◽  
Temperature Treatment ◽  
Fruit And Vegetable ◽  
Color Formation ◽  
Low Temperature Treatment ◽  
Organoleptic Characteristics ◽  
Vegetable Raw Materials ◽  
Method Of Evaluation

The aim of the work is to determine the color formation of multicomponent fruit and vegetable pastes and dried powder fractions at the stages of low-temperature pre-concentration and drying, as one of the factors, maintaining the quality of the products. In the production of organic plant semi-finished products an important factor is the implementation of high-quality technological operations, including heat and mass transfer, which affects the final organoleptic characteristics of products. It is important to take into account the color of raw materials at the stages of blending puree in the production of paste and powder semi-finished products, which requires the introduction of a unified method for assessing the color of raw materials at each stage of the technological operation. An analysis of traditional methods for determining color formation has been performed, as a result of which it has been found, that the most effective method of evaluation is digital, based on photo processing of the prototype. According to this method, the evaluation of color formation in the manufacture of semi-finished fruits and vegetables in accordance with the proposed recipes has been conducted. Color indices of multicomponent pastes and dried fractions based on them for three prototypes were obtained. The brightness of all samples of pastes is in the range - 36.4… 37.0 % with a purity of tone 64.7… 78.2 %, which corresponds to the reddish-orange color, was obtained. After drying the test samples of pastes to the dried fraction, it has been found, that the brightness, depending on the percentage of raw materials in a sample falls in the range of 30.5… 33.2 %, at that the coloration corresponds to colors from bluish-purple to bluish-red with a purity of tone within 34.7… 34.9 %. As a result of evaluation of organoleptic indicators, it has been found, that according to the presented research samples, the best indicators have a sample with 40 % of raw apples, 20 % of pumpkin, 30 % of cranberries and 10 % of hawthorn. The obtained research data will be useful in the development of methods for the production of semi-finished products from vegetable raw materials. The applied digital method of color determination differs in simplicity and economy in comparison with colorimetric and spectrometric

Exsolution and inversion in pigeonite from the Whin Sill, Northern England

1978 ◽  
Vol 36 (1) ◽  
pp. 474-475
Author(s):  
P.P.K. Smith
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Homogeneous Nucleation ◽  
Silicate Mineral ◽  
Antiphase Boundaries ◽  
Two Phase ◽  
Primitive Form ◽  
The Core ◽  
Nucleation Mechanisms ◽  
And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

Low temperature x-ray microanalysis of frozen-hydrated tobacco leaves

1984 ◽  
Vol 42 ◽  
pp. 284-285
Author(s):  
S. Edith Taylor ◽  
Patrick Echlin ◽  
May McKoon ◽  
Thomas L. Hayes
Keyword(s):  
Low Temperature ◽  
Lemna Minor ◽  
Root Tips ◽  
Tobacco Leaves ◽  
X Ray ◽  
Whole Cells ◽  
Carbon Coated ◽  
The Right ◽  
Beam Currents ◽  
The University

Low temperature x-ray microanalysis (LTXM) of solid biological materials has been documented for Lemna minor L. root tips. This discussion will be limited to a demonstration of LTXM for measuring relative elemental distributions of P,S,Cl and K species within whole cells of tobacco leaves.Mature Wisconsin-38 tobacco was grown in the greenhouse at the University of California, Berkeley and picked daily from the mid-stalk position (leaf #9). The tissue was excised from the right of the mid rib and rapidly frozen in liquid nitrogen slush. It was then placed into an Amray biochamber and maintained at 103K. Fracture faces of the tissue were prepared and carbon-coated in the biochamber. The prepared sample was transferred from the biochamber to the Amray 1000A SEM equipped with a cold stage to maintain low temperatures at 103K. Analyses were performed using a tungsten source with accelerating voltages of 17.5 to 20 KV and beam currents from 1-2nA.

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