Taste evaporator

Today, multistage vacuum evaporation is the predominant method used for liquid food concentrahon. Its major drawback is that it causes heat-induced deterioration of sensory (color, taste, and aroma) and nutritional (vitamins, etc.) value of the hnished product. The food industry has developed alternate methods, such as freeze concentration and thermally accelerated short time evaporation (TASTE) [20] for recovery and blending of such labile constiments for producing concentrates. Though they are currently practiced commercially, the final products in some cases do not satisfy the consumer requirement of their fresh or natural qualities. Some of these processes are energy intensive and therefore unattractive. 

Lemon and Lime Juice. Lemons and Persian limes can be extracted using the same PMC and AMC extractors described above. The juice can be concentrated in a TASTE evaporator, an APV Crepaco, Inc. evaporator, or other types of evaporators (13). Although lime juice, and especially lemon juice, are widely used as condiments on food, the bulk of concentrated juice is used to make frozen concentrated lemonade and limeade. Prozen... 

Seawater. Salt extraction from seawater is done by most countries having coastlines and weather conducive to evaporation. Seawater is evaporated in a series of concentration ponds until it is saturated with sodium chloride. At this point over 90% of the water has been removed, and some impurities, CaSO and CaCO, have been crystallized. This brine, now saturated in NaCl, is transferred to crystallizer ponds where salt precipitates on the floor of the pond as more water evaporates. Brine left over from the salt crystallizers is called bitterns because of its bitter taste. Bitterns is high in MgCl2, MgSO, and KCl. In some isolated cases, eg, India and China, magnesium and potassium compounds have been commercially extracted, but these represent only a small fraction of total world production. 

Concentration. The concentration of fmit juice requites removal of solvent (water) from the natural juice. This is commonly done by evaporation, but the derived juices may lose flavor components or undergo thermal degradation during evaporation. In freeze concentration, solvent is crystallized (frozen) in a relatively pure form to leave behind a solution with a solute concentration higher than the original mixture. Significant advantages in product taste have been observed in the appHcation of this process to concentration of certain fmit juices. 

Various extraction methods for phenolic compounds in plant material have been published (Ayres and Loike, 1990 Arts and Hollman, 1998 Andreasen et ah, 2000 Fernandez et al., 2000). In this case phenolic compounds were an important part of the plant material and all the published methods were optimised to remove those analytes from the matrix. Our interest was to find the solvents to modily the taste, but not to extract the phenolic compounds of interest. In each test the technical treatment of the sample was similar. Extraction was carried out at room temperature (approximately 23 °C) for 30 minutes in a horizontal shaker with 200 rpm. Samples were weighed into extraction vials and solvent was added. The vials were closed with caps to minimise the evaporation of the extraction solvent. After 30 minutes the samples were filtered to separate the solvent from the solid. Filter papers were placed on aluminium foil and, after the solvent evaporahon, were removed. Extracted samples were dried at 100°C for 30 minutes to evaporate all the solvent traces. The solvents tested were chloroform, ethanol, diethylether, butanol, ethylacetate, heptane, n-hexane and cyclohexane and they were tested with different solvent/solid ratios. Methanol (MeOH) and acetonitrile (ACN) were not considered because of the high solubility of catechins and lignans to MeOH and ACN. The extracted phloem samples were tasted in the same way as the heated ones. Detailed results from each extraction experiment are presented in Table 14.2. 

Thermostable pectinesterases (TSPE), operationally defined as activity that survives 5 min at 70°C, contribute most to cloud loss in juices at low temperatures and juice pH (26). The percentage of total activity that is thermostable is highly variable and differs in kinetic properties, (22, 26), ease of solubilization (28, 29), stability to low pH (25) and stability to freeze-thaw cycles (23). Some of the variability in reported total PE and TSPE may be related to limitations of current methods to quantify activity. Any processing treatment or assay condition that increases cell wall breakdown or release PE from a pectin complex would enhance detection of total and TS-PE activity. Commercially, PE is inactivated by pasteurization in a plate heat exchanger or during concentration in the TASTE evaporator. 

Hydroalcoholic extracts are made when the active constituents are insoluble in water or when a concentrated dosage form is desired. Hydro alcoholic extracts use concentrated alcohol in varying proportions with water as a solvent. Hydroalcoholic extracts are categorized as tinctures or fluid extracts, depending on the amount of alcohol used. Some patients who simply do not like the taste of alcohol may be counseled to put the dosage of tincture drops into a cup of hot liquid and let it stand for a few minutes to evaporate off most of the alcohol before ingestion. An example of an ethanolic extract is echinacea [5,6]. 

Occasionally let one or two drops of eluent fall onto a microscope slide. Evaporate the solvent and see if there are any properties of the compound that should be coming through, such as crystal shapes, tastes, smells, viscosities if oil, etc. 

Hexachlorobutadiene, also known as HCBD, perchlorobutadiene, or Dolen-Pur, is a colorless liquid. It does not evaporate or bum easily. Hexachlorobutadiene has a turpentine-like odor. Most people will begin to smell a mild to pungent odor if the compound is present in air at 1 part hexachlorobutadiene per million parts of air (ppm). It is not known how it tastes or at what level people can taste it. 

Three types of closely related cresols exist ortho-cresol (o-cresol), meta- cresol (m-cresol), and para-cresol (p-cresol). Pure cresols are colorless chemicals, but they may be found in brown mixtures such as creosote and cresylic acids (e.g., wood preservatives). Because these three types of cresols are manufactured separately and as mixtures, they can be found both separately and together. Cresols can be either solid or liquid, depending on how pure they are pure cresols are solid, while mixtures tend to be liquid. Cresols have a medicinal smell (odor) and when dissolved in water, they give it a medicinal smell and taste. Cresols do not evaporate quickly from water, but in rivers and lakes, they can be removed quickly by bacteria. Dissolved cresols can pass through soil into underground water sources. This may be a problem at hazardous waste sites where cresols are buried. Once cresols are in the water table, they may stay there for months without changing. Cresols in air quickly change and break down into smaller chemicals, some of which irritate the eyes. Cresols can also irritate the eyes. 

Carbon tetrachloride is a clear liquid that evaporates very easily. Most carbon tetrachloride that escapes to the environment is therefore found as a gas. Carbon tetrachloride does not easily burn. Carbon tetrachloride has a sweet odor, and most people can begin to smell it in air when the concentration reaches 10 parts carbon tetrachloride per million parts of air (ppm). It is not known whether people can taste it or, if they can, at what level. 

Chloric and bromic acids are not known in a free state, but only in aq. soln. and in the form of their salts. Iodic acid occurs as a white powder and in colourless crystals. Chloric and bromic acids form colourless aq. soln. which, by evaporation in vacuo,-can be cone, to syrupy viscid liquids which first redden and then bleach blue litmus. When cold the aq. soln. have no smell, but when warm, chloric acid has a smell recalling that of nitric acid. The taste is like that of a strong acid. The cone. soln. of chloric acid does not crystallize when cooled to —20°. The soln. are stable when dil., and become less stable as the concentration increases. Soln. of bromic acid can be cone, on a water-bath until they contain between 13 and 14 per cent, of HBr03 when the attempt is made to concentrate further, the soln. begins to decompose, giving ofi oxygen and bromine. When the concentration is conducted under reduced press., in the cold, the decomposition does not begin until... 

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