1. Agent for imparting kokumi consisting essentially of γ-Glu-Nva-Gly.2. Complex agent for imparting kokumi comprising, in combination, (a) γ-Glu-Nva-Gly and (b) one or at least two amino acid or peptide selected from the group consisting of γ-Glu-X-Gly, where X is an amino acid or amino acid derivative, γ-Glu-Val-Y, where Y is an amino acid or an amino acid derivative, γ-Glu-Nva, γ-Glu-Abu, γ-Glu-Ala, γ-Glu-Gly, γ-Glu-Cys, γ-Glu-Met, γ-Glu-Thr, γ-Glu- Val, γ-Glu-Orn, Asp-Gly, Cys-Gly, Cys-Met, Glu-Cys, Gly-Cys, Leu-Asp, D-Cys, γ-Glu-Met (O), γ-Glu-γ -Glu-Val, γ-Glu-Val-NH, γ-Glu-Val-ol, γ-Glu-Ser, γ-Glu-Tau, γ-Glu-Cys (S-Me) (O), γ-Glu -Leu, y-Glu-Ile, γ-Glu-t-Leu and γ-Glu-Cys (S-Me) .3. Nutritional composition comprising between 0.1 mlr.d. (Ppb) to 99.9 wt.% Γ-Glu-Nva-Gly.4. Food composition according to claim 3, comprising from 0.01 to 50 ppm (Ppm) γ-Glu-Nva-Gly from 0.005 to 80 wt.% ingredients derived from pork, and other health ingredienty.5. Food composition according to claim 3, comprising from 0.01 to 50 ppm γ-Glu-Nva-Gly from 0.005 to 80 wt.% ingredients derived from beef, and other health ingredienty.6. A method of preparing a food or beverage product, or intermediate product used for preparing a food or beverage product comprising the steps of: adding a flavor enhancer consisting essentially of γ-Glu-Nva-Gly, the food ingredients by mixing them together iesli required cooking food ingredientov.7 resulting mixture. A method according to claim 6, wherein the step of adding a flavor enhancer consisting essentially of γ-Glu-Nva-Gly, the food ingredients by mixing them together includes the step of monitoring the concentration of γ-Glu-Nva-Gly in the semi-finished product used for food product or beverage at a level in the range of 0.01 to 999900 m.d.8. A method according to claim 7, further comprising:1. Агент для придания кокуми, состоящий в основном из γ-Glu-Nva-Gly.2. Комплексный агент для придания кокуми, содержащий, в комбинации, (а) γ-Glu-Nva-Gly и (b
