Minor components, of food

The hydroxybenzoic acid derivatives (HBAs) are phenolic compounds with a general structure C6-C1. The related C6-Ci acids (phenylacetic acids) occur occasionally as minor components of foods. 

Vitamins are minor components of foods that play an essential role in human nutrition. Many vitamins are unstable under certain conditions of processing and storage (Table 9-1), and their levels in processed foods, therefore, may be considerably reduced. Synthetic vitamins are used extensively to compensate for these losses and to restore vitamin levels in foods. The vitamins are usually divided into two main groups, the water-soluble and the fat-soluble vitamins. The occurrence of the vitamins in the various food groups is related to their water-or fat-solubility. The relative importance of certain types of foods in supplying some of the important vitamins is shown in Table 9-2. Some vitamins function as part of a coenzyme, without which the enzyme would be ineffective as a biocatalyst. Frequently, such coenzymes are phosphorylated forms of vitamins and play a role in the metabolism of fats, proteins, and carbohydrates. Some vitamins occur in foods as provitamins—compounds that are not vitamins but can be changed by the body into vitamins. Vitamers are members of the same vitamin family. 

Analysis of pesticide residues is usually performed using GC, and the main field of application of LC is the simultaneous detection of very different pesticides in a single analysis, due to the lack of limitations of volatility or stability compared with GC. Compared with other analyses of minor components of food, determination of residues in food needs lower detection limits and, usually, laborious sample preparation and fractionation before the LC separation can take place. 

Surfactants adsorb on almost any dispersed substrate, and therefore it is not surprising that they also adsorb onto minor components of food systems and affect their stability against oxidation or hydrolysis, affect their crystallization patterns, and modify their dissolution behavior. 

Miraliakbari H and Shahidi F. 2008. Antioxidant activity of minor components of tree nut oils. Food Chem 111 (2) 421—427. 

Soybeans and soybean products contain high levels of protein, carbohydrates, and lipids (Table 11.6.1). As minor components of complex mixtures, isoflavones must first be separated from the bulk of the matrix constituents prior to analysis. Efficient extraction methods for isoflavones should account for their diverse structures, chemical properties, and the food matrix of which they are constituents. This unit describes a practical way of extracting isoflavones from soybean products in their natural forms using readily available solvents and laboratory equipment. 

Cholesterol serves two important functions in the body. First, it is a minor component of cell membranes, where it helps to keep the membranes fluid. Second, it serves as the body s starting material for the synthesis of all other steroids, including the sex hormones. Although news reports sometimes make cholesterol sound dangerous, there would be no life without it. The human body obtains its cholesterol both by synthesis in the liver and by ingestion of food. Even on a strict no-cholesterol diet, an adult is able to synthesize approximately 800 mg per day. 

Recent developments in the area of oils and fats has led to the production of specialty lipids from novel sources such as fruit seeds, nuts, and other minor plant sources. In addition, preparation of structured lipids for a myriad of applications has been of interest. Minor components of oils and fats may be isolated during processing and used as nutraceutical and functional food ingredients. Examples are lecithin, phytosterols, tocopherols, and tocotrienols, among others. Obviously, the health-promoting potential of such products is also of interest. 

Phospholipids (Figure 3) are constituents of membranes and are only minor components of oils and fats, sometimes responsible for cloudiness. They are usually removed during degumming, the residue from soybean oil processing being a source of phospholipids used as food emulsifiers. The term lecithin is used very loosely for such material, and it may variously mean phosphatidylcholine, mixed glycerophospholipids, or cmde phospholipid extracts from various sources. Where possible, more specific nomenclature or the source and purity should be used (14). 

The thiobarbituric acid (TBA) test was proposed over 40 years ago and is now one of the most extensively used methods to detect oxidative deterioration of fat-containing foods (41). During lipid oxidation, malonaldehyde (MA), a minor component of fatty acids with 3 or more double bonds, is formed as a result of the degradation of polyunsaturated fatty acids. It is usually used as an indicator of the lipid oxidation process, both for the early appearance as oxidation occurs and for the sensitivity of the analytical method (42). In this assay, the MA is reacted with thiobarbituric acid (TBA) to form a pink MA-TBA complex that is measured spectrophotometrically at its absorption maximum at 530-535 nm (Figure 2) (9,43,44). The extent of oxidation is reported as the TBA value and is expressed as milligrams... 

TABLE 5. Overview of the Different Minor Components in Food Oiis and Fats. 

Triglycerides are a major component of the diet. Most people consume 100 g of fat and oil per day. The fatty acid constituents of these TGs are mainly longMedium-chain TGs are minor components of the diet. Even in foods known to contain medium-chain l Gs, such as coconut milk and mother s milk, long-chain TGs predominate. 

The specific distribution of FA in a molecule also occurs in polar lipids (see Chapter 5). However, it does not affect the properties of the respective food product to such a high degree as the distribution in TAG, because polar lipids are only minor components in food. 

Non-starch polysaccharides (NSP) Plant cell-wall NSP Other NSP Many different types of polysaccharides Main constituents arabinose, xylose, mannose, galactose, glucose, uronic acids Many types of constituents Escape digestion in the small intestine and are fermented to different extents Encapsulate and slow absorption of nutrients. Good marker for naturally fiber-rich diets for which health benefits have been shown Food additives. Minor components of the human diet. The amounts added to foods are known and regulated... 

These minor components of cocoa have become an intense focus of research interest because of their demonstrated beneficial effect on health. The interest has been recently reinforced by the scientific opinion on the substantiation of a health claim related to cocoa flavanols and the maintenance of normal endothelium-dependent vasodilation issued by the European Food Safety Authority (EFSA) Panel on Dietetic Products, Nutrition and Allergies (NDA) [3], In order to obtain the claimed effect, 200 mg of cocoa fiavanols should be consumed daily. This amount could be provided by 2.5 g of high-fiavanol cocoa powder or 10 g of high-flavanol dark chocolate. This reinforces the scientific interest in the development of sensitive and rapid analytical methods for determining these minor components in cocoa, cocoa products, and chocolate. Another important aspect is related to the development of analytical methodologies for sensitive and selective identification and quantification of the main metabolites of cocoa polyphenols in biological samples in order to understand their bioavailability and their contribution to health. 

Over the last few years, due to improvements in the packing material of the chromatographic columns, the use of UHPLC technique has improved the reported HPLC methodologies in terms of peak efficiency, peak resolution, speed, sensitivity, and solvent consumption. However, this technique must operate at high backpressures [41-43]. Another advantage of the UHPLC technique is that, given this high peak resolution, when it is combined with MS as the detector system, it is less susceptible to matrix effects (MEs), one of the main problems when the MS is used to quantify minor components in food samples. This is because an efficient UHPLC separation may contribute to a reduction in ion suppression, when this is only produced by the coelution of two different compounds [44]. 

The book covers food analysis for beneficial compounds, such as the determination of folate, vitamin content analysis, applications for avocado metabolite studies, virgin olive oil component analysis, lactose determination in milk, and analysis of minor components of cocoa and phenolic compounds in fruits and vegetables. With contributions by experts in interdisciplinary fields, this reference offers practical information for readers in research and development, production, and routing analysis of foods and food products. 

Campos-Vega R, Loarca-Pina G, Oomah BD (2010) Minor components of pulses and their potential impact rat human health. Food Res Int 43 461-482... 

The composition of the lauric oils, with a high content of short and medium chain saturated fatty acids, makes them especially suitable for use in confectionery, as coating and filling fats, and in vegetable oil-based dairy products such as filled milk, whipped cream, coffee whitener. The lauric oils are also of importance in the oleochemicals industry, and they are unique among food oils in that about one half of their use is in oleochemicals. Analyses of the various kernel oils listed in the tables show differences in the proportions of the short- and medium-chain fatty acids. Some of the oils would be of particular value where a special application is available for a fatty acid that is only a minor component of coconut or palm kernel oil. 

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