Abstract:
The present invention has discovered that flavone glycosides represented by Formula I set forth below have unexpected and advantageous flavor enhancement and modification properties: 
                                 
wherein R 1  is selected from the group consisting of H and CH 3 , R 2  is selected from the group consisting of H and OH, and R 3  is a 7-O-glycoside. Thus, the flavone glycosides of the present invention can be used to enhance or modify the flavor of orally consumable compositions, such as foodstuff, chewing gums, dental and oral hygiene products, and medicinal products.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the use of flavone glycosides to enhance or modify the warming effect of orally consumable compositions, such as foodstuff, chewing gums, dental and oral hygiene products, and medicinal products. 
     BACKGROUND OF THE INVENTION 
     There is an ongoing need in the flavor industry to identify new flavor compounds such as warming compounds, which are known to provide a sensation of warmth. Previously reported warming compounds include 1′-acetoxychavicol acetate, 1′-acetoxyeugenol acetate derivative, polyhydric alcohols,  capsicum  powder, a  capsicum  tincture,  capsicum  extract, capsaicin, homocapsaicin, homodihydrocapsaicin, nonanoyl vanillyl amide, nonanoic acid vanillyl ether, vanillyl alcohol alkyl ether derivatives, such as vanillyl ethyl ether, vanillyl butyl ether, vanillyl pentyl ether, and vanillyl hexyl ether, isovanillyl alcohol alkyl ethers, ethylvanillyl alcohol alkyl ethers, veratryl alcohol derivatives, substituted benzyl alcohol derivatives, substituted benzyl alcohol alkyl ethers, vanillin propylene glycol acetal, ethylvanillin propylene glycol acetal, ginger extract, ginger oil, gingeol, gingeron, and black or white pepper extract [U.S. Pat. Nos. 6,504,048 and 6,838,106; U.S. Publication No. 2009/0054498]. However, these warming compounds may cause irritation when used in high amount, while exhibit short-duration effect or insufficient strength when used in low amount. There remains a challenge in developing novel warming compositions that provide long-lasting and strong warming effect in the absence of negative attributes such as irritation. Thus, there is a particular need to identify new warming enhancers that enhance or modify the warming flavor, preferably lower the levels of warming compounds in various food products to provide advantageous properties as well as economy of use. 
     SUMMARY OF THE INVENTION 
     The present invention has discovered that flavone glycosides represented by Formula I set forth below have unexpected and advantageous warming enhancement and modification properties: 
     
       
                 
         
             
             
         
      
     
     wherein R 1  is selected from the group consisting of H and CH 3 , R 2  is selected from the group consisting of H and OH, and R 3  is a 7-O-glycoside. 
     One embodiment of the invention relates to a warming composition comprising a warming compound and a warming enhancer represented by Formula I provided above. 
     Another embodiment of the invention relates to a process of enhancing or modifying warming effect to a material selected from the group consisting of foodstuff, a chewing gum, a dental or oral hygiene product, and a medicinal product comprising the step of incorporating an effective amount of a warming compound and an olfactory effective amount of a warming enhancer of Formula I provided above. 
     These and other embodiments of the present invention will be apparent by reading the following specification. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     It is known to those with the skill in the art that Formula I as defined above provides compounds such as the following: 
     
       
                 
         
             
             
         
      
     
     It is known to the skill in the art that 
     Formula II represents apigenin 7-O-glucoside; 
     Formula III represents acacetin 7-O-glucoside; 
     Formula IV represents luteolin 7-O-rutinoside; and 
     Formula V represents acacetin 7-O-rutinoside. 
     The compounds of the present invention can be obtained from natural plants such as, for example, but not limited to,  Bupleurum marginatum, Conyza sumatrensis, Fortunella margarita, Malabaila suaveolens, Solanum lyratum, Origanum syriacum, Chrysanthemum morifolium ramat, Olea europaea L., Teucrium zanonii, Cyclopia subternata, Caucalis platycarpos L., Reseda luteola L., Paeonia section  Moutan, Catharanthus roseus, Saussurea medusa, Duabanga grandiflora, Agrimonia eupatoria L., Lawsonia inermis L., Ficus lyrata , and  Celtis australis  [Lin, et al., Food Chemistry 120(1): 319-326 (2010); Liu, et al., Journal of Molecular Structure 883-884: 38-47 (2008)]. 
     The compounds of the present invention are also generally commercially available. For example, apigenin 7-O-glucoside (Formula II) and acacetin 7-O-rutinoside (Formula V) can be obtained from INDOFINE Chemical Co., Inc. (United States), acacetin 7-O-glucoside (Formula III) can be obtained from Apin Chemicals Ltd. (United Kingdom), and luteolin 7-O-rutinoside (Formula IV) can be obtained from AnalytiCon Discovery GmbH (Germany). 
     The compounds of the present invention are surprisingly found to have unexpected properties of enhancing and modifying warming effect in flavors, which are demonstrated to be advantageous for augmenting or imparting taste enhancement or somatosensory effect in foodstuff, chewing gums, oral hygiene products, and medicinal products by providing flavor enhancement and a preferred overall flavor profile. 
     The compounds of the present invention can be used, alone or as a mixture, in combination with a warming compound or a mixture of warming compounds. For example, the compounds may be employed to enhance the perceived warming effect of  capsicum  extract since a large amount of  capsicum  extract may cause adverse effect such as irritation. In a preferred embodiment, the compounds are used in combination with  capsicum  extract such as  capsicum oleoresin  in a weight ratio of at least about 1:1000, preferably from about 100:1 to about 1:100, more preferably from about 20:1 to about 1:20, and even more preferably from about 5:1 to about 1:5. 
     As used herein, a warming compound is understood to mean a compound that provides warmth sensation. A warming enhancer is understood to mean a compound that enhances or modifies the warming effect of a warming compound. 
     The terms “flavor composition” and “flavor formulation” are understood to mean the same and refer to a formulation that is intended for providing a flavor character to foodstuff, medicinal products, and cosmetic products. 
     The terms “warming composition” and “warming formulation” are understood to mean the same and refer to a formulation that is intended for providing warming effect to foodstuff, medicinal products, and cosmetic products. The warming composition of the present invention is a composition comprising a warming enhancer of the present invention. 
     The term “enhancing” in the phrase “enhancing or modifying a warming formulation” is understood to mean making the warming formulation greater in effectiveness or providing the warming formulation with an improved warmth character. The term “modifying” is understood to mean raising the warming formulation to a more desirable character. 
     The phrase “an effective amount of a warming compound” is understood to mean that the amount of the warming compound is above the threshold for detection by humans and, therefore, capable of enhancement by the addition of the compounds of the present invention. As the taste perception can be subjective, this threshold necessarily varies from person to person even with the same warming compound and further with the nature and form of the products containing the warming compound. 
     As used herein, an olfactory effective amount is understood to mean the amount of the compound in a flavor composition that alters the characteristics of the composition, or enhances or modifies the flavor, taste, and aroma reaction contributed by another ingredient in the composition. The overall flavor, taste, and aroma effect of the composition will be the sum effect of all flavor ingredients. The olfactory effective amount will vary depending on many factors including other ingredients, their relative amounts, and the effect that is desired. 
     The usage level of the compounds of the present invention varies depending on the product in which the compounds are employed. Generally, the level of the compounds employed in a product is greater than about 1 part per billion by weight, preferably from about 10 parts per billion to about 100 parts per million by weight, more preferably from about 50 parts per billion to about 10 parts per million by weight. 
     As used herein, foodstuff includes both solid and liquid ingestible materials for man or animals, which materials usually do, but need not, have nutritional value. Thus, foodstuff includes food products, such as meats, gravies, soups, convenience foods, malt, alcoholic and other beverages, milk and dairy products, seafood, including fish, crustaceans, mollusks and the like, candies, vegetables, cereals, soft drinks, snacks, dog and cat foods, other veterinary products and the like. 
     When the compounds of the present invention are used in an orally consumable composition, they can be combined with conventional flavoring ingredients or adjuvants, which are well known in the art. Requirements of such flavoring ingredients and adjuvants are that: (1) they be organoleptically compatible with the compounds of the present invention whereby the flavor of the ultimate consumable composition to which the compounds are added is not detrimentally affected by the use of such flavoring ingredients and adjuvants; and (2) they be ingestible and thus nontoxic or otherwise non-deleterious. In addition, the orally consumable composition can broadly include other flavor materials, vehicles, stabilizers, thickeners, surface active agents, conditioners, and flavor intensifiers. 
     The following are provided as specific embodiments of the present invention. Other modifications of this invention will be readily apparent to those skilled in the art. Such modifications are understood to be within the scope of this invention. As used herein all percentages are weight percent unless otherwise noted, and ppm is understood to stand for parts per million. 
     EXAMPLE 
     The warming compositions of  capsicum oleoresin  (2 ppm) combined with apigenin 7-O-glucoside (Formula II), acacetin 7-O-glucoside (Formula III), luteolin 7-O-rutinoside (Formula IV), and acacetin 7-O-rutinoside (Formula V), respectively, were evaluated by a trained sensory panel using an intensity scale of 0 to 5, where 0=none, 1=minimal, 3=moderate, and 5=intense.  Capsicum oleoresin  (2 ppm) alone was used as the control. Sensory scores were reported in the following: 
     
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                   
                 Concentration 
                   
                 Flavor 
               
               
                 Composition 
                 (flavone glycoside) 
                 Flavor Profile 
                 Intensity 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Capsicum oleoresin 
                 0 
                   
                 2 
               
               
                 Capsicum oleoresin/ 
                 1 ppm 
                 Quick onset, 
                 2.5 
               
               
                 Formula II 
                   
                 strong heat on the 
               
               
                   
                   
                 tip of tongue 
               
               
                 Capsicum oleoresin/ 
                 1 ppm 
                 Some heat 
                 2.5 
               
               
                 Formula III 
                   
                 enhancement 
               
               
                 Capsicum oleoresin/ 
                 1 ppm 
                 Heat 
                 2.5 
               
               
                 Formula IV 
                   
                 enhancement, 
               
               
                   
                   
                 delayed 
               
               
                 Capsicum oleoresin/ 
                 1 ppm 
                 Strong heat, 
                 3.5 
               
               
                 Formula V 
                   
                 enhancement 
               
               
                   
                   
                 delayed, more 
               
               
                   
                   
                 delocalized 
               
               
                   
               
             
          
         
       
     
     As shown above, Formulas II, III, IV, and V all enhanced the warming effect of  capsicum oleoresin.