Flavor enhancers nucleotides

The 5 nucleotide of inosine inosimc acid (CioHi3N40gP) is added to foods as a flavor enhancer What is the structure of mosinic acid" (The structure of inosine is given in Problem 28 21)... 

Flavor enhancers are substances that carry the property of umami (see Chapter 7) and comprise glutamates and nucleotides. Glutamic acid is a component amino acid of proteins but also occurs in many protein-containing foods as free glutamic acid. In spite of their low protein content, many vegetables... 

The chemical structure of the nucleotides is shown in Figure 7-21. They are purine ribonucleotides with a hydroxyl group on carbon 6 of the purine ring and a phosphate ester group on the 5 -carbon of the ribose. Nucleotides with the ester group at the 2 or 3 position are tasteless. When the ester group is removed by the action of phos-phomonoesterases, the taste activity is lost. It is important to inactivate such enzymes in foods before adding 5 -nucleotide flavor enhancers. 

Hazardous Decomp. Prods. Heated to decomp., emits toxic vapors of CO, CO2, NOx, POx emits toxic fumes under fire conditions Storage Keep under argon sensitive to humidity refrigerate store at 4 C keep tightly closed Uses Biochemical research flavor enhancer in foods molecular biology nucleosides/nucleotides Manuf./Distrib. Fluka http //www.sigma-aldrich.com, Pfaltz Bauer http //www.pfaltzandbauer. com, Sigma... 

Definition A nucleotide found in muscle and other tissues that is formed by the deamination of AMP and on hydrolysis yields inosine Uses Flavor enhancer in foods seasoning Inositol... 

Process flavors — Process flavors are generally used to create meaty flavors (e.g., chicken) for snacks. As discussed in an earlier chapter (Chapter 9), they are created based on process flavor technology from amino acid/sugar reactions plus other ingredients such as flavor enhancers (MSG and/or 5 -nucleotides), antioxidants, emulsifiers, flavoring (e.g., smoke), and anticaking agents (since they will be sold as powders). 

Inosine monophosphate (IMP, disodium salt) and 5 -guanosine monophosphate (GMP, disodium salt) have properties similar to MSG but heightened by a factor of 10-20. Their flavor enhancing ability at 75-500 ppm is good in all food (e. g. soups, sauces, canned meat or tomato juice). However, some other specific effects, besides the MSG effect , have been described for nucleotides. For example, they imprint a sensation of higher viscosity in liquid food. The sensation is often expressed as freshness or naturalness , the expressions body and mouthfeel being more appropriate for soups. 

Inosine monophosphate and GMP are synthesized in the human body and play diverse roles in cellular metabolism [3]. Dietary nucleotides are energetically useful to fulfill the liver s need for nucleotides [4], although people with high levels of uric acid (UA) in their blood and urine must avoid foods with these compounds, because degradation of purine nucleotides leads to the formation of UA [3]. In addition, these flavor enhancers are added by food manufacturers to improve the taste of food. Therefore, monitoring these compounds in foods or food seasonings is very important in food-quality or foodprocessing control. 

Salt is the best known taste enhancer for a variety of foods. Monosodium glutamate (MSG) and nucleotides, such as inosine monophosphate (IMP) and guanosine monophosphate (GMP), are known to enhance flavor and are recognia as the "umami taste" in Oriental cuisine. They have longer aftertastes than the "basic... 

The 5 -Nucleotides. Also dating back many years in the Far East was the knowledge that bonita tuna possesses a substance that very effectively enhances the flavor of foods. However, it was not until 1913 dial S. Kodama (Tokyo University) commenced a serious investigation directed toward identifying and isolating the substance from tuna. Initially. Kodama believed that the substance was the histidine salt of 5 -inosinic acid, but later found that the substance was actually 5 -inosinic acid itself. This nucleotide was found to be many more times as effective as MSG. Further research by Kodama and others has shown that these nucleotides are present in many natural foods. 

POTENTIATOR. A term used in the flavor and food industries to characterize a substance that intensifies the taste of a food product to a far greater extent than does an enhancer. The most important of these are the 5 -nucleotides. They are approved by the FDA. Their effective concentration is measured in parts per billion, whereas that of an enhancer such as MSG is m parts per thousand. The effect is thought to be due to synergism, Potentiators do not add any taste of their own, but intensify7 the taste response to substances already present in the food. 

Some 51-nucleotides have been implicated as flavor modifiers, and orange juice is known to contain relatively large quantities of certain 5 -nucleotides, with a total level of about 40 ppm (25, 26). In a study of the influence of six 5 -nucleotides at the 10 ppm level on the taste threshold of octanal in water (Table II), two of the 5 -nucleotides (GMP and ADP) significantly lowered the threshold of octanal (23). GMP is known to enhance flavor in foods, but ADP had been reported to have little or no modifying effect on food flavors (23). Analysis of variance showed that GMP, ADP and GDP enhanced the flavor of octanal in aqueous... 

Source From A. Kuninaka, Recent Studies of 5 -Nucleotides as New Ravor Enhancers, in Flavor Chemistry, I. Hornstein, ed., 1966, American Chemical Society. 

The nucleosides GMP, IMP and XMP are known to enhance food flavor. They display a synergistic action with soditim glutamate (Demain, 1968). Nucleotide derivatives are recommended for the treatment of thromboses. Inosine (under the name Riboxin) is a pharmaceutical agent used in the treatment of various heart and liver diseases in Russia. Ribosides and adenine support high levels of ATP in erythrocytes. Deoxyribonucleotides are used in chemical syntheses of some antitumor and antiviral preparations (Sidermene et al., 1985). In addition, 2-deoxyribonucleotides (-sides) serve as substrates for enzymatic and chemical syntheses of specific oligodeoxyribonucleotides, which at present are widely used as biosensors (Efremenko et al, 1990). 

High Performance Liquid Chromatography (HPLC) has traditionally found little use in most flavor companies. The typical flavor house has focused on volatile substances, and thus GC was the primary tool. However, HPLC finds application in flavor houses that work with nonvolatile components such as capsaicins, colorants, savory enhancers (MSG or the 5 -nucleotides), salts, or other flavor adjuncts. It can also be used to advantage for flavor chemicals that are difficult to analyze by GC, i e those that are low in volatility, thermally unstable, or difficult to resolve from the matrix or other flavor components. 

Quality and nutritional values Mushrooms contain large amounts of flavor and aroma producing 5 -ribonucleotides. Common mushroom (Agaricus) contains about 50 mol and fresh shiitake mushroom from 182 to 235 mol of 5 -nucleotides per 100 g fresh weight as compared to vegetables, which contain 1 to 10 mol of these compounds per 100 g fresh weight. The process of drying not only increases the shelf life of mushrooms but also enhances the flavor with a... 

The organoleptic properties of food are one of the characteristics that define food quality and govern food selection. Between the food additives that are added to increase its taste and palatability, free L-glutamic acid, as its sodium salt monosodium glutamate (MSG), imparts an intrinsic taste of its own, termed umami, the fifth taste. Umamt means delicious in Japanese, and it is attributed to the sensory properties of MSG and some nucleotides, such as sodium 5 -inosinate (IMP) and sodium 5 -guanyl-ate (GMP). MSG enhances the flavor of certain foods such as meat, poultry, seafood, and vegetables. 

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