Applications in Food Chemistry

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 

Abstract The aim of the present chapter is to present the current research and potential applications of chemoinformatics tools in food chemistry. First, the importance and variety of molecular descriptors and physicochemical properties is delineated, and then a survey and chemical space analysis of representative databases with emphasis on food-related ones is presented. A brief description of methods commonly used in molecular design, followed by examples in food chemistry are presented, such methods include similarity searching, pharmacophore modeling, quantitative 

Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, Florida 34987 

Advances in Food and Nutrition Research, Volume 58 2009 Elsevier Inc. 

Karina Martinez-Mayorga and Jose L. Medina-Franco 

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In the same way as linear discriminant analysis is the most-used classification method, stepwise selection by LDA (SLDA) is the selection method that shows the greatest number of applications in food chemistry. 

Chemoinformatics— Applications in Food Chemistry Karina Martinez-Mayorga and Jose L. Medina-Franco... 

Martinez-Mayorga K, Medina-Franco JL (2009) Chemoinformatics - applications in food chemistry. Adv Food Nutr Res 58 33-56... 

When this is said there exists in food chemistry a strong awareness of the importance of validation, and the necessity of validating models for unknown samples is often highlighted. One reason is that many of the regression models are in (daily) use to predict quality of various food products and reference measurements are often taken routinely as to check the performance. It is fair to say that more soft sciences are not put to the test similarly to applications in food chemistry and analytical chemistry in general. As validation has been the topic in many publications this chapter is more of a discussion of the principle rather than presenting specific applications. 

The literature dealing with robust statistics is very broad. Over the past several years a number of book chapters, mtorials and review papers have been published, for example [61-69]. Even though robust techniques seem to be very popular in different fields of science, their applications in food chemistry are relatively scarce. 

Many pesticides are neurotoxicants poisoning the nervous system. A number of pesticides are acetyl cholinesterase inhibitors (Serat and Mengle 1973). Generally, pesticides determination has been performed by GC since the 1960 s (Morrison and Durham 1971 Fournier et al. 1978). There are no reference materials for pesticides in urine or serum, although as with PAHs there are a number biological matrices certified for the content of various pesticides available for environmental food and agriculture analysis and which may have some application in clinical chemistry. 

In the late 1980s H. Martens and T. Naes (1989) broadly introduced the use of infrared data together with PLS for quantitative analyses in food chemistry, and thereby opened the window to numerous successful applications in various fields of chemical industry, at present time. 

Major applications of chitosan were previously focused on sludge dewatering, food processing, and metal ion chelation until the mid-1980s. Further, it has received considerable attention for its commercial applications in agriculture, chemistry, biomedical, food, cosmetic, and biotechnology industries (Alasalvar et ah, 2002 Knorr, 1984 Kurita,... 

The reader should find it helpful that the most recent published articles of the last few years are discussed. As in the first edition, special attention is paid to reversed-phase separations without neglecting other HPLC techniques. Specialists describe in detail, step by step, sample preparation and separation conditions. The applications to food chemistry are specific and practical. The book will once again find a large audience in the fields of chromatography, analytical chemistry, and, especially, food chemistry and food technology. 

During the last twenty years, biochemical reactions performed by microorganisms or catalyzed by microbial enzymes have been extensively evaluated from the viewpoint of synthetic organic chemistry, and as a consequence they have been shown to have a high potential for both theoretical and practical applications in synthetic chemistry. Many attempts to utilize biological reactions for practical synthetic processes have been made - for example, for the preparation of pharmaceuticals, fine chemicals, food additives, and commodity chemicals. Such synthetic technology is called microbial transformation, or alternatively, microbial conversion, biotransformation, bioconversion, or enzymation [1,2]. 

Syrbe, A., Fernandes, P. B., Dannenbeig, F., Bauer, W. J., and Klostermeyer, H. 1995. Whey protein-polysaccharide mixtures polymer incompatibility and its application, in Food Macromolecules and Colloids, eds. E. Dickinson and D. Lorient, pp. 328-339, The Royal Society of Chemistry, London. 

This book African Natural Plant Products New Discoveries and Challenges in Chemistry and Quahty is a traly international effort to address and highlight the remarkable chemical diversity, and range of African plants and products that are used for a wide variety of applications in foods, flavorings, medicine, health and nutrition. We are honored that so many African researchers, as well as scientists from other regions of the world were so wilhng to share their expertise. This book with 29 scientific articles and reviews was written by over 80 scientific authors, with the majority of them African (50%). 

The quality assessment of food and fodder products requires analysis of protein, carbohydrates and fat. The enzyme electrode-based analyzers originally developed for clinical chemistry have found only limited application in food analysis because they are only suitable for the determination of one parameter, mostly glucose or a disaccharide. The increasing concern for food quality require new types of biosensors allowing residual and hygiene control and on-line measurement of age and freshness (Tschannen, 1988). 

Proctor, A. Soybean oil extraction and processing. Soy Applications in Food. Soybeans Chemistry, Technology and Utilization K. Liu, Ed. Chapman and Hall New York, NY, 1997, pp. 297—346. 

In synthetic chemistry, SFE can be attractive as an alternative to conventional methods for purification of reaction products such as vitamins, pharmaceuticals and many other high-value products [4], Its technical use is currently mainly restricted to applications in food industry for extraction from natural products and in some cases for the fractionation of the products [5]. This chapter therefore focuses on these types of production and purification processes, but all the methodologies discussed may be readily adapted to synthetic applications. Equipment for carrying out separation processes of various sizes is available from coimnercial suppliers, and is described in more detail in Chapter 2.1 and elsewhere [1]. 

K. Aitzetmdller. Applications of an HPLC amine modifier for sugar analysis in food chemistry. Chromatoeranhia 13 432-436 (1980). 

Hwang, W. Z., Coetzer, C., Turner, N. E., and Lee, T. C., Expression of bacterial ice nucleation gene in a yeast Saccharomyces cerevisiae and its possible application in food freezing processes, Journal of Agricultural and Food Chemistry, 49 4662-4666, 2001. 

Enzymatic process is the main method to produce cyclodextrins (CDs), and so far, chemical methods have been reported. CD is industrially produced from starch, glucogen, malto-oligosaccharides, and other dextrins through catalysis by cyclodextrin glucosyl transferase (CGTase). More and more researchers focus on the essential CGTase to prepare CD due to its wide applications in food, medicine, cosmetics, environmental protection, and analytical chemistry. 

The introduction of improved sample preparation and separation techniques has made IR a popular identification tool in food chemistry (Eskamani, 1975). One of the most useful applications of IR spectroscopy in food processing is the identification of cis trans unsaturation. This subject has been partly dealt with under the heading Fatty acids (Section 9.1.4a). In the food industry, cis trans determination may be helpful in the detection of fat adulteration. Bartlett and Chapman (1961) used IR spectroscopy to determine hydrogenated (saturated) fats in butter. Butter... 

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