Fluid in foods

Fluid flow may be steady or unsteady, uniform or nonuniform, and it can also be laminar or turbulent, as well as one-, two-, or three-dimensional, and rotational or irrotational. One-dimensional flow of incompressible fluid in food systems occurs when the direction and magnitude of the velocity at all points are identical. In this case, flow analysis is based on the single dimension taken along the central streamline of the flow, and velocities and accelerations normal to the streamline are negligible. In such cases, average values of velocity, pressure, and elevation are considered to represent the flow as a whole. Two-dimensional flow occurs when the fluid particles of food systems move in planes or parallel planes and the streamline patterns are identical in each plane. For an ideal fluid there is no shear stress and no torque additionally, no rotational motion of fluid particles about their own mass centers exists. 

In the automotive, office equipment, and other industries, the mechanical properties of fluoropolymers are beneficial in low-friction bearings and seals that resist attack by hydrocarbons and other fluids. In food processing, the Food and Drug Administration (FDA) has approved fluoropolymer grades as fabrication material for equipment due to their resistance to oil and cleaning materials, and their anti-stick and low friction properties. 

Uses Lubricant for rubber molds, textile fibers, metalworking fluids in foods and food pkg. humectant, solvent in cosmetics hair preps. in gas chromatography in lacquers paints paper coatings polishes solvent for nitrocellulose plasticizer binder in ceramic pastes, print-... 

The water-soluble polysaccharides are widely used to control the rheology of aqueous fluids in food, pharmaceutical, personal care, latex paints, and cosmetic products. They also have some uses in hard-smface care (toilet bowl cleaners, bathroom cleaners, etc.) and fabric care applications such as fabric softeners. The patent application EP 596580 Al is an example of a fabric softening composition thickened by cationic starch [39]. Specific examples of other consumer products will be provided in Sec. E.G. and Modified Natural Organic Thickeners. 

Supercritical Fluid Extraction. Supercritical fluid (SCF) extraction is a process in which elevated pressure and temperature conditions are used to make a substance exceed a critical point. Once above this critical point, the gas (CO2 is commonly used) exhibits unique solvating properties. The advantages of SCF extraction in foods are that there is no solvent residue in the extracted products, the process can be performed at low temperature, oxygen is excluded, and there is minimal protein degradation (49). One area in which SCF extraction of Hpids from meats maybe appHed is in the production of low fat dried meat ingredients for further processed items. Its apphcation in fresh meat is less successful because the fresh meat contains relatively high levels of moisture (50). 

Fluid mixing is a unit operation carried out to homogenize fluids in terms of concentration of components, physical properties, and temperature, and create dispersions of mutually insoluble phases. It is frequently encountered in the process industry using various physical operations and mass-transfer/reaction systems (Table 1). These industries include petroleum (qv), chemical, food, pharmaceutical, paper (qv), and mining. The fundamental mechanism of this most common industrial operation involves physical movement of material between various parts of the whole mass (see Supplement). This is achieved by transmitting mechanical energy to force the fluid motion. 

Propylene Glycol. Propylene glycol, the second largest use of propylene oxide, is produced by hydrolysis of the oxide with water. Propylene glycol has very low toxicity and is, therefore, used direcdy in foods, pharmaceuticals (qv), and cosmetics, and indirectly in packaging materials (qv). Propylene glycol also finds use as an intermediate for numerous chemicals, in hydrauhc fluids (qv), in heat-transfer fluids (antifreeze), and in many other apphcations (273). 

For more specific analysis, chromatographic methods have been developed. Using reverse-phase columns and uv detection, hplc methods have been appHed to the analysis of nicotinic acid and nicotinamide in biological fluids such as blood and urine and in foods such as coffee and meat. Derivatization techniques have also been employed to improve sensitivity (55). For example, the reaction of nicotinic amide with DCCI (AT-dicyclohexyl-0-methoxycoumarin-4-yl)methyl isourea to yield the fluorescent coumarin ester has been reported (56). After separation on a reversed-phase column, detection limits of 10 pmol for nicotinic acid have been reported (57). 

CS derivatives/salts have found limited use as detergents (25), antistatic coatings for photographic film (26), oil drilling fluids (25), thickeners in food, cosmetics, and pharmaceuticals (27). They have been recommended for use as cation exchangers (28,29). Also, sulfated polysaccharides have recendy shown interesting antiviral activity (30). 

Histamine is the biological amine, playing an important role in living systems, but it can also cause unnatural or toxic effects when it is consumed in lai ge amounts. It can occur with some diseases and with the intake of histamine-contaminated food, such as spoiled fish or fish products, and can lead to undesirable effects as headache, nausea, hypo- or hypertension, cai diac palpitations, and anaphylactic shock syndrome. So, there is a need to determine histamine in biological fluids and food. 

E. Anklam, H. Berg, L. Matliiasson, M. Shaiman and P. Ulbeith, Super-a itical fluid exti action (SEE) in food analysis areview . Food Additive Contam. 15 729-750 (1998). 

The individual characteristics and uses of the basic grades of the austenitic irons are given in Table 3.55. The major uses for these materials occur in the handling of fluids in the chemical and petroleum industries and also in the power industry and in many marine applications. The austenitic irons are also used in the food, soap and plastics industries where low corrosion rates are essential in order to avoid contamination of the product. Ni-Resist grades Type 2, 3 or 4 are generally used for such applications but the highly alloyed Type 4 Ni-Resist is preferred where low product contamination is of prime importance. 

LAXATIVES. The nurse records file results of administration on the patient s chart. If excessive bowel movements or severe prolonged diarrhea occur or if file laxative is ineffective, the nurse notifies file primary health care provider. If a laxative is ordered for constipation, the nurse encourages a liberal fluid intake and an increase in foods high in fiber to prevent a repeat of this problem. 

Because the scent of a flower may be due to hundreds of different compounds, it is difficult for perfume manufacturers to duplicate floral scents. Establishing the identities and relative amounts of the components of a fragrance was actually impossible until the development of chromatography. Related techniques are used in forensic laboratories to match samples of fluids, by food manufacturers to test product quality, and to search for evidence of life on other planets. All these techniques depend on subtle differences in intermolecular forces to separate compounds. 

Jarvenpaa, E.P., Rostiala, N., and Huopalahti, R., Utilization of supercritical fluid techniques in the fractionation of natural pigments, in Proceedings of 3rd International Congress on Pigments in Food, Le Berre, Quimper, France, 2004, 29. 

NMR spectroscopy is one of the most widely used analytical tools for the study of molecular structure and dynamics. Spin relaxation and diffusion have been used to characterize protein dynamics [1, 2], polymer systems[3, 4], porous media [5-8], and heterogeneous fluids such as crude oils [9-12]. There has been a growing body of work to extend NMR to other areas of applications, such as material science [13] and the petroleum industry [11, 14—16]. NMR and MRI have been used extensively for research in food science and in production quality control [17-20]. For example, NMR is used to determine moisture content and solid fat fraction [20]. Multi-component analysis techniques, such as chemometrics as used by Brown et al. [21], are often employed to distinguish the components, e.g., oil and water. 

Increased motility results in decreased contact between ingested food and drink and the intestinal mucosa, leading to reduced reabsorption and increased fluid in the stool. Diarrhea resulting from altered motility is often established after other mechanisms have been excluded. IBS-related diarrhea is due to altered motility. 

In humans, the large intestine usually receives about 500 mL of fluid-like food material (chyme) per day. As... 

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