Tomato paste, concentrated

Camomille Cod liver oil Propolis Concentrated tomato paste Cocoa... 

In a very recent study, Consonni et al. (2009) evaluated the geographical discrimination of Chinese and Italian triple concentrate tomato paste samples by 1H NMR (a typical 1H NMR spectrum with expansion and assignments is reported in Fig. 4.18) and multivariate statistical analysis. Despite a good market for imported triple concentrated tomato paste from China, the biggest world tomato producer, very few indications suggest the possibility of identifying the origin and the quality of different... 

Notwithstanding that different tomato cultivars and ripening stages were usually used to obtain the final product, the authors achieved an excellent discrimination of triple-concentrated tomato paste samples... 

FIGURE 4.19 PCA score plot performed by considering all triple concentrated tomato paste samples filled triangles and dots represent Italian and Chinese samples, respectively. PCI = 38.0%, PC2 = 21.9%. R2 = 79.6%, and Q2 = 56.0%. (From Consonni et al, 2009.)... 

Consonni, R., Cagliani, L. R., Stocchero, M., and Porretta, S. (2009). Triple concentrate tomato paste Discrimination between Italian and Chinese products. J. Agric. Food Chem. 57, 4506 4513. 

Earlier, Sanz et al 6 had found tomato pulp to give a little furosine (7.3 mg per 100 g), with only a trace of 2-l uroylmethyl-y-aminobutyric acid, but, on storage for 4 d at 50 °C and an a, of 0.44, the corresponding amounts were 70.9 and 245.4 mg per 100 g and the amounts for the 2-furoylmethyl derivatives of Ala, Ser + Thr + Glu, and Asp + Asn had come up from 0 to 60.9, 103.5, and 300.5 mg per 100 g, respectively. 2-Furoylmethyl-y-aminobutyric acid was also the most abundant furoyl-methyl derivative obtained from commercial tomato products, ranging from 0 for whole peeled tomatoes to 87.6 mg per 100 g dry matter for double-concentrated tomato paste. Furosine was usually the second most abundant derivative obtained, ranging up to 42.8 mg per 100 g, but its amount exceeded that for 2-furoylmethyl-7-aminobutyric acid in the two samples of tomato pulp analysed. 

Plan the spotting of the samples as illustrated on Fig. 29.2. Five spots will be applied. The first and fifth spots will be /3-carotene solutions supplied by your instructor. The second, third, and fourth spots will have your tomato paste extracts in different concentrations. Use a pencil to mark the placement of the spots lightly according to Fig. 29.2. 

Isolation of Volatiles from Tomato Condensate. Condensate from commerical tomato paste production using vacuum concentration was stored at 5°C in the dark and used within a few days. 

Qualitative Approach. Aqueous condensate was obtained from commercial tomato processors from the vacuum (ca. 100mm) concentration of fresh tomato to give tomato paste. The volatile components from this condensate were obtained by continuous liquid liquid extraction using first pentane and then diethyl ether. 

Two aroma reconstitution experiments have been performed for tomato paste. In the first experiment [81 ] a synthetic mixture containing the odorants nos. 2, 8, 9, 15, 17 (3-isomer), 21 and l-nitro-2-phenylethane was used. The concentration of the first six odorants was in the range shown in Table 6.46. In the second experiment [82] the aroma model contained the 15 odorants in the concentration equal to those reported in Table 6.46. A comparison indicated that the aroma of this mixture was very close to the aroma of the original. Obviously, l-nitro-2-phenylethane does not contribute to the aroma of tomato paste. 

Food and additives Animal proteins, Arabic gum, beet juice concentrate, blood products, buttermilk, caramel coloring, carrot juice and concentrate, cheese, cilantro, coffees, egg yolk, gelatins, guar gum, soy sauce, skim milk, tomato paste, yogurt, potato ... 

Fresh tomatoes and canned tomato products are very convenient foods for the busy homemaker because (1) the raw vegetable lends itself well to cold soups, relishes, and salads (2) only a few minutes of simmering is needed to cook the raw vegetable (3) canned tomato juice may be used to make a wide variety of molded gelatin salads, (4) canned tomato paste or puree may be us when concentrated sauces are desired, and (5) the flavor and color of the tomato blends well with those of many other ingredients. Some examples of easy-to-prepare tomato dishes and a few gourmet-type preparations follow ... 

Tomato Paste and Tomato Powder Processing Control. Evaporation of water in the concentration plant, which operates under reduced pressures, brings about a progressive increase in solids content of the tomato pulp until a paste of the desired density is produced (i). Concentration to a final solids content of 28 - 30 % is the most common practice in Europe, and this paste forms the double concentrate of commerce. The temperature of the paste must be raised to at least 90°C before it is filled into cans in order to prevent the survival of microorganisms. 

As Table II shows, the concentrations of amino acids have been greatly diminished during drum-drying of CB- and HB-tomato paste at the same time there is a strong increase in the concentration of the corresponding Amadori compounds and of visible browning (A (420 nm) = absorbance value at 420 nm). 

Table III shows that the concentrations of all listed volatile compounds are far above the sensory threshold values (determined in water) thus strongly contributing to flav(M they may contribute to off-flavor, if th exceed certain concentrations. Therefore the Strecker aldehydes and dimethyl sulfide listed in Table III can be used as very sensitive marker substances for sensory changes during heat processing of tomatoes, espedally 2- and 3-methylbutanal, since their concentrations are more than hundredfold higher in tomato flakes than in tomato paste.

In the case of tomato processing pyrrolidone-carboxylic acid (PCA) formed by cyclization of glutamine turned out to be the most sensitive marker for an early detection of heat treatment. PCA already appears during the break process. In tomato paste all the glutamine present has been converted to PCA as a result of heat treatment during the concentration process, whereas only relatively small amounts of hydroxymethylfurfural (HMF) could be detected. 

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