Flavor of tomato

Petro-Turza, M. Flavor of tomato and tomato products. Ibid., 1986-1987, 2(3) 309. 

Petro-Turza, M. "Flavor of Tomato and Tomato Products". Food Reviews International. 1986-87, , 309. 

The flavor of tomatoes is intensified by slowly roasting them in an oven. Cherry tomatoes are the easiest to use (yellow and red varieties work equally well), and cherry plum tomatoes are particularly good. It s worth preparing as many tomatoes as possible at a time, and use as much garlic and herbs as you like. 

Studies on banana tissue slices have shown that valine and leucine concentrations increase about threefold following the climacteric rise in respiration [10]. Radioactive labeling studies have shown that valine and leucine are transformed into branched chain flavor compounds that are essential to banana flavor (2-methyl propyl esters and 3-methyl butyl esters, respectively). As can be seen in Figure 4.6, the initial step is deamination of the amino acid followed by decarboxylation. Various reductions and esterifications then lead to a number of volatiles that are significant to fruit flavor (acids, alcohols, and esters). Recent work has shown that amino acids play a role in apple flavor as well. For example, isoleucine is the precursor of 2-methyl butyl and 2-methyl butenyl esters in apples [24,25]. An unusual flavor compound, 2-isobutylthiazole, has been found to be important to the flavor of tomato. It is hypothesized that this compound is formed from the reaction of 3-methyl-l-butanal (from leucine) with cysteamine. 

RG Buttery. Quantitative and sensory aspects of flavor of tomato and other vegetables and fruits. In TE Acree, R Teranishi, eds. Flavor Science, Sensible Principles and Techniques. ACS Professional Reference Book. Washington, DC American Chemical Society, 1993, pp 259-286. 

Basil (Sweet Basil). Basil consists of the brown, dried leaves and tender stems of Ocimum basilicum L. (Labiatae), an aimual native to India, Africa, and Asia, and cultivated in Egypt, southern Erance, Morocco, the Mediteranean countries, and the United States. Basil is one of the oldest known herbs, and it is reported that there are perhaps 50—60 poorly defined Ocimum species which can only be identified according to their chemical components. The flavor of the basihcum type is warm, sweet, somewhat pungent, and pecuhar, ie, methyl chavicol and linalool. It is used with meats, fish, certain cheeses, and tomato-based salads. The fresh leaves are ground and known as pesto with pastas. It is the main component of the Hqueur Chartreuse. 

Free glutamates exist in certain cheeses (such as parmesan), in tomato products, and in soy sauce. These products are often used to enhance the flavor of meat dishes. Proteins can be hydrolyzed by heat, releasing free glutamates. Cooked meats, especially grilled meats, get some of their taste from free glutamates. 

The major source of lycopene is tomato products but it also occurs in water melons, guavas, pink grapefruit, and in small quantities in at least 40 plants.14 The structure of lycopene is shown in Fig. 8.2. It is a long chain conjugated hydrocarbon and its structure suggests that it would be easily oxidized in the presence of oxygen and isomerized to cis compounds by heat. Both of these reactions occur in purified solutions of lycopene but in the presence of other compounds normally present in tomatoes, lycopene is more stable. Actually the absorption of lycopene in the human gut is increased by heat treatment probably because the breakdown of the plant cells makes the pigment more accessible. Preparations from tomatoes are widely used in pizza, pasta, soups, drinks and any product compatible with the flavor and color of tomatoes. 

Do not overwater excessive, unnecessary watering can reduce the flavor of crops such as tomatoes, and wet soil can encourage fungal rots. 

The flavor of the tomato pulls together odor and taste... 

From intact vegetable crops, apart from tuber, bulb, and root crops, tomatoes and asparagus show potential for radiation treatment. The development of fungal decay in tomatoes caused by Alternaria, Botrytis, or Rhizopus spp. can be controlled using doses of approx. 3 kGy. However, softening and the loss of characteristic flavor may occur. Doses of 0.1 kGy and above result in a delay of ripening of tomatoes [43]. 

Dittmann, B., Zimmermannn, B., Engelen, C., Jany, G., Nitz, S. (2000) Use of the MS-sensor to discriminate between different dosages of garlic flavoring in tomato sauce. J. Agric. Food Chem. 48 2887-2892. 

In studies on the flavors of fresh and processed tomatoes, Buttery and coworkers [76, 77] also found that the number of odorants needed to simulate either the fresh tomato flavor or the flavor of a tomato paste was much lower than the number of aroma compounds detected by the OAV concept [4],... 

Sulfur Heterocyclics. Sulfur containing compounds (thiols, thiophenes, thiazoles,. .. etc.) play a major role in the flavor of raw and processed foods. These compounds have characteristic flavor notes and the flavor thresholds are mostly low. Several reviews (ill, 112, 113) demonstrate the important role of sulfur compounds in food flavors. Organoleptic properties of these compounds may be pleasant, strong nut-like odor of U-methyl-5-vinylthiazole which is present in cocoa (llU) objectionable pyridine-like odor of thiazole (115) quinoline-like odor of benzothia-zole (ll6) strong tomato leaf-like odor of isobutylthiazole (117) and bread crust flavor of acetyl-2-thiazoline (ll8). A mixture of oxazoles, thiazoles, thiazolines, imidazoles, trithiolanes and... 

The majority of heterocyclic compounds are formed through thermal interactions of reducing sugars and amino acids, known as the Halliard reaction. Other thermal reactions such as hydrolytic and pyrolytic degradation of food components (e.g. sugars, amino acids, vitamins) and the oxidation of lipids also contribute to the formation of heterocyclic compounds responsible for the complex flavor of many foodstuffs. Heterocyclic compounds may also be formed enzymatically in vegetables (tomatoes, bell peppers, aspara-... 

Aroma properties of some alkylthlazoles have been reviewed (30). The most typical alkylthiazole is probably 2-isobutylthlazole. This compound was Isolated from tomato flavor and was described as having a strong green odor resembling that of tomato leaf (31). When added to canned tomato puree or paste at levels of 20 to 50 ppb, 2-lso-butylthlazole develops an intense fresh tomato-like flavor. Most of the alkylthlazoles are described as green, nutty and vegetable-like (32, 33). 

In all cases the keto acids seem to be formed by typical a-ketogluta-rate-linked, pyridoxal phosphate-dependent transaminases (EC 2.6.1.6, etc.) (9, 154, 156, 157). There has been little study of isolated, presumably specific enzymes in connection with flavors, although the leucine and alanine aminotransferases of tomato have been precipitated with (NH4)oS04 (164, 165). Transaminase activity in Saccharomyces cere-visiae has a pH optimum of 7.2 (154), and a-ketoglutarate is the only amino group recipient (154, 166). Only aspartate and amino acids with hydrophobic side chains are acted on (154). 

Dried goji berries are the most popular and most common product format. Having the consistency of low-moisture raisins, they may be an acquired taste for some consumers to appreciate the unfamiliar blend of tomato-nut-cranberry flavors Goji berry pieces are being used more often as ingredients in nutrition bars and cereals. Just thirty dried goji berries equal one fruit serving. 

The oxidation products of lipids include volatile aldehydes and acids. Therefore, lipids are one of the major sources of flavors in foods. For example, much of the desirable flavors of vegetables such as tomatoes, cucumbers, mushrooms, and peas (Ho and Chen, 1994) fresh fish (Hsieh and Kinsella, 1989), fish oil (Hu and Pan, 2000) and cooked shrimp (Kuo and Pan, 1991 Kuo et al., 1994), as well as many deep-fat fried foods such as French-fried potatoes (Salinas et al., 1994) and fried chicken (Shi and Ho, 1994), are contributed by lipid oxidation. LOX-catalyzed lipid oxidation produces secondary derivatives, e.g., tetradecatrienone, which is a key compound of shrimp (Kuo and Pan, 1991). The major difference between the flavors of chicken broth and beef broth is the abundance of 2,4-decadienal and y-dodeca-lactone in chicken broth (Shi and Ho, 1994). Both compounds are well-known lipid oxidation products. A total of 193 compounds has been reported in the flavor of chicken. Forty-one of them are lipid-derived aldehydes. 

Cass, B.J. et al., Production of tomato flavor volatiles from a crude enzyme preparation using a hollow-fiber reactor, Biotechnol. Bioeng., 67, 372, 2000. 

Tomato volatiles are important to both aroma and flavor and their concentration increases with ripening (1061. Because many of the volatile aroma compounds of tomatoes apparently result from enzymatic breakdown of carotene pigments (1071. CA, which delays pigment synthesis, can be expected to delay volatile production. 

Recently Buttery et al. (77) showed the importance of logarithmic values of odor units (log [Uo]) in the evaluation of tomato flavor. The logarithmic factor is correlated to Weber-Fechner s law (72) in regard to odor intensity. Weber-Fechner s law is defined in the following equation ... 

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