Food-related components

In recent years HPLC technique has been perfected. A large number of food components may be separated with HPLC. Many excellent books have been published on HPLC theory and thousands of articles have been written on chromatographic separations of food-related components. 

Contents I. Introduction 34 II. Molecular Descriptors and Physicochemical Properties 36 III. Molecular Databases and Chemical Space 37 IV. Chemoinformatics in Food Chemistry 40 V. Examples of Molecular Similarity, Pharmacophore Modeling, Molecular Docking, and QSAR in Food or Food-Related Components 43 A. Molecular similarity 43 B. Pharmacophore model 47 C. QSAR and QSPR 48 D. Molecular docking 49 VI. Concluding Remarks and Perspectives 52 Acknowledgments 53 References 53... 

Figure 2.2 shows some of these methods and how they can be used in combination it also shows the outline of the following sections in this chapter. First, the concept of chemical space, including a sketch of molecular descriptors, physicochemical properties, and databases is presented. Then, a brief description of molecular similarity, pharmacophore modeling, docking, and QSAR models with the incorporation of examples of food-related components is described. These methods are mainly used to develop and analyze SAR and the resultant models can be used to perform virtual screening. Comprehensive reviews of each of these methods are described elsewhere (Alvarez and Shoichet, 2005 Leach and Willet, 2003 Varnek and Tropsha, 2008). 

PHARMACOPHORE MODELING, MOLECULAR DOCKING, AND QSAR IN FOOD OR FOOD-RELATED COMPONENTS... 

Going deeper into the comparison and classification of chemical structures, a set of computational techniques are available. This section is organized to present a brief description of currently used methodologies, namely molecular similarity, pharmacophore modeling, molecular docking, and QSAR followed by application of these methods to food-related components. 

All of the computational methods presented here have been used in connection with food or food-related components, and they can potentially be applied to other areas in food chemistry. 

In several aspects, the approach toward finding a new functional ingredient is quite similar to the development of new pharmaceuticals. Bioinformatics tools have been largely employed as the first steps for drug design and recently, they are beginning to be used in coimection with food or food-related components in several areas of food chemistry [72]. It is widely reported that natural compounds in the diet can improve health conditions and prevent disease by direct interaction with key proteins in metabohc pathways. For example, pure monacolin K (lovastatin) has been shown to be effective in reducing total cholesterol and LDL-cholesterol concentrations in individuals with hypercholesterolemia and is a well-known inhibitor of HMG-CoA reductase. 

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. 

Perceived risk is a key component of consumer behavior (Frewer et al., 1994). However, decision making and behavior are often analyzed and reported only in terms of perceived risk (Brockhaus, 1980 Srinivasan and Ratchford, 1991). Perceived risk, however, only partially explains actual behavior. It is only when combined with a person s attitude toward risk can we understand and predict behavior to food-related issues. 

F MacRitchie. Identifying the baking quality related components of wheat flours. Cereal Food World 34 548-552, 1989. 

In this respect, the texture comprises all physical characteristics of foods related to the response to applied force and measured objectively in terms of force, distance, and time. Texture depends on the various constituents and structural elements of foods in which the microstructure components are formed and then clearly recognized in terms of flow and deformation during different processing treatments. 

These examples of small and large deformations illustrate the complexity of the rheological parameters of lipid-based food systems. Small deformation testing can provide completely different information from large deformation testing. Therefore, information from more than one test is necessary if one wants to understand how the structure relates to the rheological behavior of food system components. 

At such a crucial Juncture, intervention from social scientists is valid not only within the context of the economic changes in the organic sector but in all related components of the organic world , including the operation of networks of stakeholders and motivations for consumption of organic food. In this volume... 

In the food chemistty field, a number of databases have been compiled some, thongh not all, contain chemical stractures. In certain cases, food components in databases are not single chemicals, but rather mi rtures [1], Nonetheless, conducting nseful analyses without necessarily reporting all chemical stmctures is still feasible, as has been reported by us [2] and by others [3], When chemical stmctures are available, however, additional analyses and comparisons can be performed [2, 4]. In other cases, food databases do not contain chemical information, but instead other food-related information, for example, databases containing specific diets to be followed in hospitals or information about food items shelf life, etc. 

No discussion of the use of biotransfarmation in lipid chemistry would be complete without some mention of chemical transformation relating to fatty adds. Fatty adds are a major component of the lipid fraction of organisms. They are mainly found as components of triglycerides and phospholipids, although they may occur in smaller quantities as free fatty adds or as esters of other moieties. Fatty adds, either as free adds or as esters, are valuable commodities in the food and cosmetics industries. They may also serve as precursors of a variety of other compounds. 

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. 

Water birds have not been shown to be directly affected by acidification. However, the prey of waterbirds may be of concern as these lower food-chain organisms may have elevated levels of toxic metals related to acidification of their habitat. Moreover, most water birds rely on some component of the aquatic food-chain for their high protein diet. Invertebrates that normally supply caJcium to egg-laying birds or their growing chicks are among the first to disappear as lakes acidify. As these food sources are reduced or eliminated due to acidification, bird habitat is reduced and reproductive rate of the birds is affected. The Common Loon is able to raise fewer chicks, or none at all, on acidic lakes where fish populations are reduced 37 and 5S). However, in some isolated cases, food supplies can be increased when competitive species are eliminated (e.g.. Common Goldeneye ducks can better exploit insects as food when competition from fish is eliminated). The collective influences of acidification are difficult to quantify on a specific area basis but for species that rely on a healthy aquatic ecosystem to breed, acidification remains a continuing threat in thousands of lakes across eastern North America 14). 

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