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Results for “freeze-drying”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

The effect of variety and maturity on the quality of freeze-dried carrots. The effect of microwave blanching on the nutritional and textural quality of freeze-dried spinach

Using carrots, the quality of freeze-dried products was studied to determine the optimum varieties and maturation stages for quality attributes such as appearance, flavor, texture, and nutritive value. The quality of freeze-dried carrots is discussed in terms of Gardner color, alcohol insoluble solids, viscosity, and core/cortex ratio. Also, microwave blanching of freeze-dried spinach was studied to determine vitamin interrelationships, anatomical changes, and oxidative deteriorations in terms of preprocessing microwave treatments. Statistical methods were employed in the gathering of data and interpretation of results in both studies.

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NASA NTRS1971

Modification of physical properties of freeze-dried rice

Freeze cycling process consists of alternately freezing and thawing precooked rice for two cycles, rice is then frozen and freeze-dehydrated in vacuum sufficient to remove water from rice by sublimitation. Process modifies rice grain structure and porosity, enabling complete rehydration in one minute in hot water.

Huber, C. S.↗
NASA NTRS1972

Quick, easy to prepare freeze-dried soups

Major advantages of soups are that they totally rehydrate in less than five minutes in water at approximately 150 deg F, maintain flavor and quality stability for two weeks in a 100 F environment, and remain stable for considerably longer at ambient temperatures. They are suitable for either household or field use.

Ramirez, R. V.↗
NASA NTRS1972

Mechanisms of deterioration of nutrients phase 1

Experimental methods are studied by which freeze-dried foods of improved quality are produced. Considered are: (1) Factors effecting the loss of butanol from frozen aqueous food solutions during storage; (2) a freeze-drying microscope system for observing solidification processes in organic mixtures and aqueous inorganic salt solutions; (3) browning of high quality freeze-dried foods with minimal organoleptic and nutritional detoriation; (4) retention of PVP-n-propanol in freeze-dried food models; and (5) effects of freezing rate and sucrose immersion on taste and texture of freeze-dried apple slices.

Karel, M.↗
NASA NTRS1978

Mechanisms of deterioration of nutrients

Methods for improving the quality of freeze-dried foods were investigated. Areas discussed include: (1) microstructure of freeze-dried systems, (2) structural changes in freeze-dried systems, (3) artificial food matrices, and (4) osmotic preconcentration to yield improved freeze-dried products.

Karel, M.↗
NASA NTRS1984

Properties of simulated comet mantle

The properties of freeze-dried dilute dispersions of dust in water ice are of considerable interest in studies of comet nucleus mantles. The formation of a rind residue produced by the sublimation of water ice containing various amounts of fine clay particles may be an important process. A simulation of the development of the dry dust rind on the surface of comets is presented. This rind is the result of preferential ice sublimation. The development and disruption of this rind and its subsequent levitation by water vapor flow is studied. The most interesting rind simulant is produced by dispersing 0.1 micron particles of montmorillonite in water in concentrations of 10%, 1%, and 0.1%. These dispersions are then sprayed into liquid nitrogen in the form of 100 micron droplets. The frozen droplets are then freeze-dried in a vacuum which prevents the ice temperature from rising above -30 C. Sublimation of the nitrogen and the water produced dry rinds. The most striking result was the development of large cohesive matrices of individual clay particles, and in some cases a continuous cohesive crust. Scanning electron microscope (SEM) observations reveal that the material formed by freeze-drying the 0.1% dispersion does not retain the original spherical shape of the sprayed 100 micron droplets; instead it consists of a continuous filamentary network, as shown in the SEM stereo micrographs.

Fanale, F. P.↗
NASA NTRS1978

Compression of rehydratable vegetables and cereals

Characteristics of freeze-dried compressed carrots, such as rehydration, volatile retention, and texture, were studied by relating histological changes to textural quality evaluation, and by determining the effects of storage temperature on freeze-dried compressed carrot bars. Results show that samples compressed with a high moisture content undergo only slight structural damage and rehydrate quickly. Cellular disruption as a result of compression at low moisture levels was the main reason for rehydration and texture differences. Products prepared from carrot cubes having 48% moisture compared favorably with a freshly cooked product in cohesiveness and elasticity, but were found slightly harder and more chewy.

Burns, E. E.↗
NASA NTRS1970

Crew provisions

Freeze-dried diet and personal hygiene for space crew

Source record↗
NASA NTRS1978

Practical and efficient magnetic heat pump

Method for pumping heat magnetically at room temperature is more economical than existing refrigeration systems. Method uses natural magneto-thermal effect of gadolinium metal to establish temperature gradient across length of tube. Regenerative cyclic process in which gadolinium sample is magnetized and gives off heat at one end of tube, and then is demagnetized at other end to absorb heat has established temperature gradients of 144 degrees F in experiments near room temperature. Other materials with large magnetothermal effects can be used below room temperature. Possible commercial applications include freeze-drying and food processing, cold storage, and heating and cooling of buildings, plants, and ships.

Brown, G. V.↗
NASA NTRS1980

Meals in orbit

Space foods which will be available to the Space Shuttle crew are discussed in view of the research and development of proper nutrition in space that began with the pastelike tube meals of the Mercury and Gemini astronauts. The variety of food types proposed for the Space Shuttle crew which include thermostabilized, intermediate moisture, rehydratable, irradiated, freeze-dried and natural forms are shown to be a result of the successive improvements in the Apollo, Skylab and Apollo Soyuz test project flights. The Space Shuttle crew will also benefit from an increase of caloric content (3,000 cal./day), the convenience of a real oven and a comfortable dining and kitchen area.

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NASA NTRS1981

Evaluation of engineered foods for Closed Ecological Life Support System (CELSS)

A system of conversion of locally regenerated raw materials and of resupplied freeze-dried foods and ingredients into acceptable, safe and nutritious engineered foods is proposed. The first phase of the proposed research has the following objectives: (1) evaluation of feasibility of developing acceptable and reliable engineered foods from a limited selection of plants, supplemented by microbially produced nutrients and a minimum of dehydrated nutrient sources (especially those of animal origin); (2) evaluation of research tasks and specifications of research projects to adapt present technology and food science to expected space conditions (in particular, problems arising from unusual gravity conditions, problems of limited size and the isolation of the food production system, and the opportunities of space conditions are considered); (3) development of scenarios of agricultural production of plant and microbial systems, including the specifications of processing wastes to be recycled.

Karel, M.↗
NASA NTRS1981

Treatment of CELSS and PCELSS waste to produce nutrients for plant growth

The research program entitled 'Development of a Prototype Experiment for Treating CELSS (Controlled Ecological Life Support Systems) and PCELSS (Partially Controlled Ecological Life Support Systems) Wastes to Produce Nutrients for Plant Growth' consists of two phases: (1) the development of the neccessary facilities, chemical methodologies and models for meaningful experimentation, and (2) the application of what methods and devices are developed to the interfacing of waste oxidation with plant growth. Homogeneous samples of freeze-dried human feces and urine have been prepared to ensure comparability of test results between CELSS waste treatment research groups. A model of PCELSS food processing wastes has been developed, and an automated gas chromatographic system to analyze oxidizer effluents was designed and brought to operational status. Attention is given the component configuration of the wet oxidation system used by the studies.

Modell, M.↗
NASA NTRS1981

To Produce Nutrients for Plant Growth

On July 1, 1979 a new research program entitled "Development of a Prototype Experiment for Treating CELSS and PCELSS Wastes to Produce Nutrients for Plant Growth" was undertaken by the Massachusetts Institute of Technology and the Georgia Institute of Technology under grant from the National Aeronautics and Space Administration's Ames Research Center. The program was designed to be completed over a five-year period, with the work divided into two phases. Phase I covers approximately two years and involves the development of necessary facilities, chemical methodologies and models to allow meaningful experiments during Phase II, which will involve interfacing waste oxidation with plant growth. Homogeneous samples of freeze-dried human feces and urine have been prepared to assure comparability of results among various CELSS waste treatment research groups. A model of food processing wastes within a PCELSS was developed, and an initial batch of waste was prepared. An automated gas chromatographic system to analyze oxidizer effluents was designed and is operational. A state-of-the-art quantitative elemental analysis capability, built around inductively coupled plasma emission spectroscopy and atomic absorption spectroscopy using electrothermal atomization, has been demonstrated. A continuous flow wet oxidation system was constructed and is now operational.

Michael Modell↗
NASA NTRS1983

Chlorophyll and carotenoid pigments of prochloron (prochlorophyta)

High-performance liquid chromatography (HPLC) with a gradient-elution technique was utilized to separate and quantify chlorophylls a and b as well as major carotenoid pigments present in freeze-dried preprations of prochloron-didemnid associations and in Prochloron cells separated from host colonies. Results confirm earlier spectrophotometric evidence for both chlorophylls a and b in this prokaryote. Chlorophyll a:b ratios range from 4.14 to 19.71; generally good agreement was found between ratios determined in isolated cell preprations and in symbiotic colonies (in hospite). These values are 1.5 to 5-fold higher than ratios determined in a variety of eukaryotic green plants. The carotenoids in Prochloron are quantitatively and qualitatively similar to those found in various freshwater and marine blue-green algae (cyanopbytes) from high-light environments. However, Prochloron differs from cyanophytes by the absence of myxoxanthophyll and related glycosidic carotenoids. It pigment characteristics are considered sufficiently different from those of cyanophytes to justify its assignment to a separate algal division.

Paerl, H. W.↗
NASA NTRS1987

Making Highly Porous Ceramics

Rigid, lightweight insulation withstands temperatures greater than 1,400 degrees C made by cryogenic freeze-drying process. New insulation expected to have solid content as low as 1 percent by volume and to be mechanically isotropic.

Green, David J.↗
NASA NTRS1988

Spectral changes in conifers subjected to air pollution and water stress: Experimental studies

The roles of leaf anatomy, moisture and pigment content, and number of leaf layers on spectral reflectance in healthy, pollution-stressed, and water-stressed conifer needles were examined experimentally. Jeffrey pine (Pinus jeffreyi) and giant sequoia (Sequoiadendron gigantea) were exposed to ozone and acid mist treatments in fumigation chambers; red pine (Pinus resinosa) needles were artificially dried. Infrared reflectance from stacked needles rose with free water loss. In an air-drying experiment, cell volume reductions induced by loss of turgor caused near-infrared reflectance (TM band 4) to drop after most free water was lost. Under acid mist fumigation, stunting of tissue development similarly reduced band 4 reflectance. Both artificial drying and pollutant fumigation caused a blue shift of the red edge of spectral reflectance curves in conifers, attributable to chlorophyll denaturation. Thematic mapper band ratio 4/3 fell and 5/4 rose with increasing pollution stress on artificial drying. Loss of water by air-drying, freeze-drying, or oven-drying enhanced spectral features, due in part to greater scattering and reduced water absorption. Grinding of the leaf tissue further enhanced the spectral features by increasing reflecting surfaces and path length. In a leaf-stacking experiment, an asymptote in visible and infrared reflectance was reached at 7-8 needle layers of red pine.

Westman, Walter E.↗
NASA NTRS1989

Automatic Sprout Grower

Self-contained seed-sprouting system provides environment for sprouting seeds quickly and easily. Sprouting container standard 6-oz package for dehydrated food and drink mixes in Space Shuttle. About 4 g of dry alfalfa or radish seeds vacuum-sealed in each cup, like freeze-dried foods. Sixteen cups suspended in tray. Air-and-water inlet tube links each cup to system of tubes and solenoid valves alternately furnish air and water and remove stale air. Peristaltic pump supplies water from vinyl medical-fluid bag. Small diaphragm pump supplies and exhausts air. Small circuit board times movements of air and water. Kit offers advantages to home gardeners. Apartment dwellers use it for steady production of homegrown sprouts even though they have no garden space.

Sauer, Richard L.↗