Nutritional quality of foods

Chris J. Seal and Kirsten Brandt, Newcastle University, UK 

Diet plays an important role in most of the chronic diseases that are the largest causes of morbidity and mortality in the developed world. In a reductionist approach, scientists have often made the role of individual nutrients in the maintenance of health the focus of their research. This approach, and in particular the discovery of essential nutrients and their roles in disease prevention, has been instrumental in the elimination of deficiency diseases in large parts of the world. However, nutrients are not consumed in isolation, but as components of whole foods and in an infinite number of combinations. In addition, foods contain a myriad of chemicals (or non-nutrients) which either serve no role in human metabolism or for which the role has not yet been elucidated. This introduces a significant level of complexity, which may be difficult to unravel. 

Current targets for a reduction in the total fat content of the diet are accompanied by recommendations to reduce the proportion of saturated fats in the diet in favour of unsaturated forms. In this context, organic practices, especially those for animal husbandry and feeding are more likely to result in products with lower fat content (see for example Hansson et al., 2000, and Chapter 9, Section 9.5 of this publication). Manipulating the fatty acid profile 

Studies which have attempted to demonstrate beneficial effects of consumption of organic foods can broadly be divided into two types (i) animal and human feeding studies with organic products, which include measures of changing 

Subjects Dietary comparison Response for organic compared with conventional Source 

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Martinez, W. H. Hopkins, D. T. In "14th Nutritional Quality of Foods and Feed. Part II. 

Nutritional Quality of Foods and Feeds" Friedman, M., Ed. Marcel Dekker, Inc. New York, 1975. 

JM Concon. Chemical determination of critical amino acids in cereal grains and other foodstuffs. In M Friedman, ed. Protein Nutritional Quality of Foods and Feeds. Part 1 Assay Methods—Biological, Biochemical, and Chemical. New York Marcel Dekker, 1975, pp 311-379. 

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Although significant strides have been directed at reducing fat content in food products, certain lipid ingredients and sources of fatty acids are used to enhance the health and nutritional quality of foods. For example, CLA isomers were enriched in both dairy and nondairy products to convey its anticancer and antiobesity effects that were reported repeatedly in animal studies (39). Sources of n-3 PUFAs are also added directly to infant formula to provide sufficient DHA for normal development of the nervous system during early infancy. In the United States, DHA was approved by the FDA in 2001 to be added into infant formula (40, 41). 

New developments in deodorization technology are driven mainly by the continuous need for more efficient processes and increased attention to the nutritional quality of food oils and fats. 

Dietary minerals are necessary for maintenance of normal cellular metabolism and tissue function. These nutrients participate in a multitude of biochemical and physiological processes important for health. Because of their broad biochemical activity, many of these compounds are intentionally used as functional agents in a variety of foods. On the other hand, some cations may induce a diversity of undesirable effects that influence the nutritional quality of foods. 

Lipids can degrade in frozen systems by means of hydrolysis and oxidation. Lipid oxidation is indeed one of the major causes of food spoilage. It is of great economic concern to the food industry because it leads to the development of various off-flavors and off-odors. In addition, oxidative reactions can decrease the nutritional quality of foods (Nawar, 1996). 

Hong, K.J. C.H. Lee S.W. Kim. Aspergillus oryzae GB-107 fermentation improves nutritional quality of food soybeans and feed soybean meal./. Med. Pood. 2004, 7, 430-436. 

G. R. Beecher, K. K. Stewart, and P. E. Hare, Automated High Speed Analysis of Discrete Samples. The Use of Nonsegmented, Continuous Flow. In Protein Nutritional Quality of Foods and Feeds (M. Friedman, Ed.). Marcel Dekker, New York, Part I (1975) 411. 

Undesirable changes in nutritional quality of foods are initiated by the autoxidation or enzymic oxidation of unsaturated lipids to lipid hydroperoxides. Lipid hydroperoxides and their products of decomposition can react with food components, such as amino acids, proteins and certain other biochemicals. These reactions and the potential role of hydroperoxides in causing mutagenicity are reviewed. 

H. F. Erbersdobler and V. Somoza, Forty years of fiirosine—forty years of using Maillard reaction products as indicators of the nutritional quality of foods. Mol. Nutr Food Res., 51 (2007) 423-430. 

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