Aqueous food pastes

Material and Methods Aqueous Food Pastes Composition... 

By far the greatest consumption of pure aqueous phosphoric acid is in the preparation of various salts for use in the food, detergent and tooth-paste industries (p. 524). When highly diluted the free acid is non-toxic and devoid of odour, and is extensively used to impart the sour or tart taste to many soft drinks ( carbonated beverages ) such as the various colas ( 0,05% H3PO4, pH 2,3), root beers ( 0.01% H3PO4, pH 5,0), and sarsaparilla ( 0.01% H3PO4, pH 4.5). 

For some recent reviews on the use of enzymes in nonconventional media, see (a) Dreyer, S., Lembrecht, J., Schumacher, J. and Kragl, U., Enzyme catalysis in nonaqueous media past, present, and future in biocatalysis in the pharmaceutical and biotechnology industries, 2007, CRC Press, pp. 791-827 . (b) Torres, S. and Castro, G.R., Non-aqueous biocatalysis in homogeneous solvent systems. Food Technol. BiotechnoL, 2004, 42, 271-277 (c) Carrea, G. and Riva, S., Properties and synthetic applications of enzymes in organic solvent. Angew. Chem. Int. Ed., 2000, 39, 2226-2254. 

Chapter HI relates to measurement of flow properties of foods that are primarily fluid in nature, unithi.i surveys the nature of viscosity and its relationship to foods. An overview of the various flow behaviors found in different fluid foods is presented. The concept of non-Newtonian foods is developed, along with methods for measurement of the complete flow curve. The quantitative or fundamental measurement of apparent shear viscosity of fluid foods with rotational viscometers or rheometers is described, unithi.2 describes two protocols for the measurement of non-Newtonian fluids. The first is for time-independent fluids, and the second is for time-dependent fluids. Both protocols use rotational rheometers, unit hi.3 describes a protocol for simple Newtonian fluids, which include aqueous solutions or oils. As rotational rheometers are new and expensive, many evaluations of fluid foods have been made with empirical methods. Such methods yield data that are not fundamental but are useful in comparing variations in consistency or texture of a food product, unit hi.4 describes a popular empirical method, the Bostwick Consistometer, which has been used to measure the consistency of tomato paste. It is a well-known method in the food industry and has also been used to evaluate other fruit pastes and juices as well. 

In most cases, the direct addition of aqueous or oil-based smoke flavourings to fish spreads or pastes is the simplest method of smoke flavouring the product. Aqueous or oil-based flavourings may also be added to the deboned fish in a mincer or silent food cutter prior to emulsification. The recommended rates of addition of the smoke flavourings are based on the final weight of the spread. The finished smoked fish flavour is developed during the pasteurisation of the final product. 

To measure overall migration with olive oil or alternative simulants, the method used with the aqueous-based food simulants is obviously not applicable. With oil-type simulants the test is carried out by measuring the loss in mass of the test specimen after exposure to the food simulant. However, most plastics absorb some of the oil that then has to be extracted and quantitatively measured before the true loss in mass can be calculated. The extraction solvent that has been most commonly used in the past is... 

Microemulsions are microheterogeneous, thermodynamically stable, spontaneously formed mixtures of oil and water under certain conditions by means of surfactants, with or without the aid of a cosurfactant. The first paper on microemulsions appeared in 1943 by Hoar et al but it was Schulman and coworkers who first proposed the word microemulsion in 1959. Since then, the term microemulsions has been used to describe multicomponent systems comprising nonpolar, aqueous, surfactant, and cosurfactant components. The application areas of microemulsions have increased dramatically during the past decades. For example, the major industrial areas are fabricating nanoparticles, oil recovery, pollution control, and food and pharmaceutical industries. This book is a comprehensive reference that provides a complete and systematic assessment of all topics affecting microemulsion performance, discussing the fundamental characteristics, theories, and applications of these dispersions that have been developed over the last decade. 

Gels from natural polymers have received increasing attention over the past years. They display novel physicochemical properties, particularly in aqueous systems, lending themselves valuable for a plethora of advanced applications, particularly in foods, cosmetics, medicine and biotechnology. However, the fundamental mechanisms operating in these gels are still poorly understood in most cases, due to the intrinsic high polydispersity (both in chain size and chemical composition), as opposed to their synthetic counterparts. 

In addition to - carrageenan food applications f., is applied in the cosmetic industry for stabilizing aqueous pastes. 

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