Food components

FoodApphca.tlons, Carbon dioxide, a nontoxic material, can be used to extract thermally labde food components at near-ambient temperatures. The food product is thus not contaminated with residual solvent, as is potentially the case when usiag coaveatioaal Hquid solveats such as methylene chloride or hexane. In the food iadustry, CO2 is not recorded as a foreign substance or additive. Supercritical solvents not only can remove oils, caffeiae, or cholesterol from food substrates, but can also be used to fractionate mixtures such as glycerides and vegetable oils iato aumerous compoaeats. 

At present, insufficient data are available, but the Tieszen and Fagre (1993) data set does give values for Bprothn and Bupid as well as Bcolla. together with Dcho and Dup and Fcho and Fup. It should therefore be possible to express BpRo and Bup in terms of the three main food components. Explicitly,... 

Finally, susceptibility to cancer may be increased by an inadequate intake of biologically active food components, which, though not classified as nutrients, may nevertheless exert important anti-carcinogenic effects over... 

The term bioavailability has various definitions. Previously, the authors of this chapter have defined bioavailability as the proportion of a nutrient (or other food component) that is digested, absorbed and utilised in normal metabolism - with the practical measurement of bioavailability usually relying upon estimates of amounts absorbed (Southon and Faulks, 2001). Biological activity, or bioactivity , has been viewed and described as a separate stage which follows on from bioavailability in the journey of a compound from food to function. However, here we present a new definition of bioavailability that recognises the functional consequences of absorption. 

KUHNAU j (1976) The flavonoids. A class of semi-essential food components their role in human nutrition , World Rev Nutr Diet, 24, 117-91. 

WANG H, PROVAN G J and HELLIWELL K (2001) Catechin, the principle bioactive compounds in green tea, and their interactions with food components , in Proc of Eur Conf on Bioactive Compounds in Plant Foods - Health effects and Perspectives for the Food Industry, 26-28 April, 2001, Tenerife, Spain, 221-2. 

BHANDARI s D, GREGORY J F 3rd (1990) Inhibition by selected food components of human and porcine intestinal pteroylpolyglutamate hydrolase activity. ,4m J Clin Nutr. 51 87-94. 

ROBERFROID M B (1996) Functional effects of food components and the gastrointestinal system chicory fructooligosaccharides. Nutr Rev. 54 S38-42. 

The destruction of antioxidants in fried food is much lower than in frying oil as the contact of food with frying oil is only short. Antioxidants are oxidised only in the surface layers. The deep frying takes only a few minutes so that only the outer layers of deep fried food are heated to 150-180°C, but the inner layers are not oxidised to more than 100°C in such a short time. Therefore, losses of antioxidants in the inner layers are negligible. Many food components, such as proteins, flavonoids or tannins, inhibit the destruction of antioxidants in fried food during the frying operation (Pokorny, 2000). 

Giusti, M.M. and Wrolstad, R.E., Characterization and measurement of anthocyanins by UV-visible spectroscopy, in Handbook of Food Analytical Chemistry Pigments, Colorants, Flavors, Texture, and Bioactive Food Components, Wrolstad, R.E. et al., Eds., John Wiley Sons, New York, 2005, 19. 

An important issue in caramel applications is their compatibility with food. The compatibility is defined as the absence of flocculation, precipitation, and haze formation. These effects are the results of colloidal interactions between charged high molecular weight components of caramel and the food components thus the charge of caramel is essential for specific food applications. ... 

Caramel color interacts with other food components. As an example, a concentration higher than 700 ppm caramel in cola increased the rate of hydrolysis of the aspartame, forming alpha-L-aspartyl-L-phenylalanine. Caramelization products inhibited enzymic browning by 85.8 and 72.2% when heated at pH 4 and 6, respectively, for 90 min. The highest inhibitory activity was found for the fraction with molecular weight of 1000 to 3000. Caramel is often used for adulteration of juices and other foods like honey or coffee. It can be determined by quantification of marker molecules such as 5-HMF, 4-Mel, and DFAs. ... 

Otles, S., Ed., Methods of Analysis of Food Components and Additives, CRC Press, Boca Raton, FL, 2005. 

Chemical and Functional Properties of Food Components Series... 

Chemical and Functional Properties of Food Components, Third Edition Edited by Zdzislaw E. Sikorski... 

In order to define this variety of food matrices, chemical composition differences that primarily influence chemical analytical measurements have to be considered. Major food components determining basic chemical make-up are the proximate composition of fat, protein, carbohydrate, ash, and moisture. Variations in ash content in general have a minor influence on analytical methods for other constituents and impact of moisture content can be controlled. Thus the major components influencing analytical performance are the relative levels of fat, protein, and carbohydrate. 

Tanner JT, Wolf WR, and Horwitz W (1995) Nutritional Metrology. The role of reference materials in improving quality of analytical measurements and data on food components. In Greenfield H, ed. Quality and Accessibility of Food-Related Data, pp 99-104. AOAC International, Gaithersburg MD. 

Extrusion texturization is a process that uses mechanical shear, heat, and pressure generated in the food extruder to change the structures of food components, including proteins (Harper, 1986). Protein texturization creates filamentous structures, crumbly surfaces, or other physical formations by restructuring or realigning folded or tightly wound globular structures into stretched, layered, or cross-linked mass (Kinsella and Franzen, 1978). 

Whey may be substituted for starch by as much as 25% in extruded corn snacks, but the product does not puff as much as com alone, as the water-holding whey protein does not react with the starch matrix (Onwulata et al., 1998). WPCs or isolates can be added along with starch to create expanded snack foods with boosted nutritional content however, without texturization, whey proteins in amounts larger than 15% may interfere with expansion, making the products less crunchy. To counter this effect, whey proteins can be texturized with starch to improve their interaction with other food components in a formulation, principally to increase extmdate expansion. In one successful application, between 25% and 35% of the flour was replaced with whey protein (Onwulata et al., 2001a,b). 

Drugs in Class III have good aqueous solubility but poor membrane permeability (e.g., bidisomide, bispho-sphonates, captopril, and furosemide). Food and food components would only be expected to influence absorption of drugs in this class if they affected some aspect... 

There are problems as well in the absorption of certain drugs in the presence of specific food components. L-Dopa absorption may be inhibited in the presence of certain amino acids formed from the digestion of proteins [43], The absorption of tetracycline is reduced by calcium salts present in dairy foods and by several other cations, including magnesium and aluminum [115-117], which are often present in antacid preparations. In addition, iron and zinc have been shown to reduce tetracycline absorption [118], Figure 17 illustrates several of these interactions. These cations react with tetracycline to form a water-in-soluble and nonabsorbable complex. Obviously, these offending materials should not be co-administered with tetracycline antibiotics. 

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