Abstract:
The present invention relates to a taste enhancer comprising clear tomato concentrate. The present invention also relates to a method of enhancing the flavor of foods comprising adding a clear tomato concentrate to the food in an amount sufficient to enhance the flavor.

Description:
This application is a National Stage Filing of PCT/IL99/00273, filed May 24, 1999. 
     FIELD OF THE INVENTION 
     The present invention relates to a novel taste enhancer. The present invention more particularly relates to a natural taste enhancer having taste enhancing properties as good as if not better than commercially available taste enhancers without the problems associated with the popular taste enhancers, in use by the food industry. 
     BACKGROUND OF THE INVENTION 
     The food industry uses flavor enhancers in a variety of savory products. These enhancers consist of monosodium glutamate (hereinafter MSG), hydrolyzed vegetable proteins, disodium salts of the 5′-nucleotides inosine monophosphate (IMP), guanosine monophosphate (GMP) and adenosine monophosphate (AMP), as well as autolysed yeasts. While all have disadvantages, the major enhancer, MSG, suffers from the problem known as Chinese Restaurant Syndrome. 
     The literature on taste enhancers is very large. A sample reference cited to show the various taste enhancers known is: S. Fuke and Y. Ueda, “Interactions between umami and other flavor characteristics”, in  Trends in Food Science  &amp;  Technology,  Special Issue on Flavor Perception, December, 1996 (Vol. 7), Elsevier Sciences Ltd. 
     In the processing of tomatoes described in IL 107,999 w have obtained two fractions: serum and pulp where the serum is further concentrated: 
                        
 
     After removing from the tomato juice the pulp, the serum is concentrated to a value that is higher than 4.5° Bx which is the normal value of crushed tomatoes to reach a Bx value of 80 Bx. It can then be hydrolyzed (or hydrolyzed and then concentrated). This product is commonly referred to as Clear Tomato Concentrate (CTC)—although it is clear only when it is in the 4.5° Bx region while at higher Bx values it becomes opaque. 
     OBJECTIVE OF THE INVENTION 
     The objective of the present invention is to afford a novel taste enhancer the Clear Tomato Concentrate which lacks the dominant tomato flavor to enable it to be used in a variety of savory food and beverage products and not only those based on tomatoes. It is a further objective of the present invention to afford a taste enhancer with little of no chance of causing Chinese Restaurant Syndrome. 
     STATEMENT OF THE INVENTION 
     A taste enhancer comprising clear tomato concentrate, and a method of enhancing the flavor of foods comprising adding a clear tomato concentrate to the food in an amount sufficient to enhance the flavor. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Tomato Serum Concentrate contains 8-10% soluble proteins and free amino acids. By hydrolyzing the proteins, one can increase the concentration of free amino acids, an in this way intensity the flavor enhancing properties of the concentrate where the hydrolysis occurs due to the presence of natural tomato acids. The rate of hydrolysis increases by heating, and depends on the time and temperature. The results of acid hydrolysis of the Tomato Serum Concentrate are shown in Table 1. 
     The tomato proteins (in the concentrate or in the serum prior to concentration) can also be hydrolyzed by enzymes at relatively low temperatures. 
     For this we have used fungal, protease/peptidase enzyme formualation developed by Novo Nordisk, and sold under the name of “flavourzyme”. Almost complete protein hydrolysis was obtained after one-hour enzyme treatment at 50°. The enzyme was subsequently inactivated by heating at 80° for a short period. The results of enzymatic hydrolysis of the Tomato Serum Concentrate are shown in Table 2. 
     Hydrolysis before or after concentration of the Tomato Serum yielde essentially the same results—namely an excellent food flavor enhancer. 
     A further embodiment of the invention is to use the flavor enhancer in powder form. Thus the Clear Tomato Concentrate, after the steps of hydrolysis and concentration, is either sprayed dried or dried using any other conventional dehydration techniques used by the food industry. The Clear Tomato Concentrate can be dried on a variety of materials such as maltodextrins, starches, sugars, carbohydrates, their derivatives or salts used as carriers to facilitate drying. 
    
    
     EXAMPLE 1 
     Clear Tomato Concentrate In Powder Form 
     Clear Tomato Concentrate and maltodextrine 19 DE (dextrose equivalent) were diluted with water to the appropriate viscosity and sprayed dried to a free flowing powder containing 3-5% moisture. 
     EXAMPLE 2 
     Flavor Enhancin Properties of Clear Tomato Concentrate 
     The food and flavor enhancing properties of the hydrolyzed and concentrated (in either order) Clear Tomato Concentrate are demonstrated in taste trials in which three different types of products (namely hamburger, Paolla rice, and vegetable soup) were prepared in three versions:
         1. Control (with no flavor enhancers).   2. Product plus pure MSG (0.3% in the final product).   3. Product plus Clear Tomato Concentrate, 60° Bx (0.5% in end Product).       

     Fifteen tasters were asked to answer two questions for each product:
         1. Which of the three samples is substantially different?   2. Which one of the remaining products do you prefer?       

     The results of the first question was as follows:
         Hamburger: All 15 participants recognized the control as different and inferior.   Paolla Rice: All 15 participants recognized the control as different and inferior.   Vegetable Soup: All 15 participants recognized the control as different and inferior.       

     The results for the second question were as follows:
         Hamburger: participants preferred the hamburger with MSG; 9 preferred the hamburger with the Clear Tomato Concentrate; and 3 had no preference.   Paolla Rice: One participant preferred the sample with MSG; 12 participants preferred the sample with Clear Tomato Concentrate; and 2 had no preference.   Vegetable Soup: Six participants preferred the soup with MSG; 5 participants preferred the sample with Clear Tomato Concentrate and 4 had no preference.       

     From this taste panel we see that the Clear Tomato Concentrate containing a total of 4-5% glutamic acid and glutamine is equal to or better than pure MSG with no problem of the Chinese Restaurant Syndrome. It is believed that this superior enhancing property is due to synergism between the glutamic acid and glutamine on the one hand and the various other amino acids present in the clear Tomato Concentrate on the other hand. 
     
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 CONCENTRATION OF FREE AMINO ACIDS IN TOMATO 
               
               
                 SERUM (60° Bx) AFTER ACID HYDROLYSIS 
               
             
          
           
               
                   
                 Compound 
                 CONC mg/kg 
               
               
                   
                   
               
             
          
           
               
                   
                 Aspartic acid 
                 11904.12 
               
               
                   
                 Threonine 
                 1117.25 
               
               
                   
                 Serine 
                 1279.80 
               
               
                   
                 Asparagine 
                 5684.74 
               
               
                   
                 Glutamic acid 
                 26501.90 
               
               
                   
                 Glutamine 
                 12942.68 
               
               
                   
                 Proline 
                 276.54 
               
               
                   
                 Glycine 
                 280.20 
               
               
                   
                 Alanine 
                 4574.41 
               
               
                   
                 Valine 
                 440.16 
               
               
                   
                 Methionine 
                 152.93 
               
               
                   
                 Isoleucine 
                 531.46 
               
               
                   
                 Leucine 
                 623.99 
               
               
                   
                 Tyrosine 
                 419.01 
               
               
                   
                 Phenylalanine 
                 1567.32 
               
               
                   
                 Gamma aminobutyric 
                 9908.32 
               
               
                   
                 Ethanolamine 
                 148.30 
               
               
                   
                 Tryptophane 
                 16.56 
               
               
                   
                 Lysine 
                 1010.62 
               
               
                   
                 Histidine 
                 1036.93 
               
               
                   
                 Arginine 
                 905.63 
               
               
                   
                 Total 
                 80321.87 
               
               
                   
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 CONCENTRATION OF FREE AMINO ACIDS IN TOMATO 
               
               
                 SERUM (60° Bx) AFTER ENZYMATIC HYDROLYSIS 
               
             
          
           
               
                   
                 Compound 
                 CONC mg/kg 
               
               
                   
                   
               
             
          
           
               
                   
                 Aspartic acid 
                 12393.07 
               
               
                   
                 Threonine 
                 1186.59 
               
               
                   
                 Serine 
                 1370.29 
               
               
                   
                 Asparagine 
                 4565.77 
               
               
                   
                 Glutamic acid 
                 26647.74 
               
               
                   
                 Glutamine 
                 11464.92 
               
               
                   
                 Proline 
                 280.31 
               
               
                   
                 Glycine 
                 332.54 
               
               
                   
                 Alanine 
                 4570.03 
               
               
                   
                 Valine 
                 488.21 
               
               
                   
                 Methionine 
                 156.60 
               
               
                   
                 Isoleucine 
                 522.86 
               
               
                   
                 Leucine 
                 612.15 
               
               
                   
                 Tyrosine 
                 435.35 
               
               
                   
                 Phenylalanine 
                 1598.48 
               
               
                   
                 Gamma aminobutyric 
                 10271.85 
               
               
                   
                 Ethanolamine 
                 167.84 
               
               
                   
                 Tryptophane 
                 26.97 
               
               
                   
                 Lysine 
                 1058.58 
               
               
                   
                 Histidine 
                 1061.20 
               
               
                   
                 Arginine 
                 926.63 
               
               
                   
                 Total 
                 79016.99