The Research On Chemical Degradation Of β-Carotene And Its Degration Products In Tobacco Sensory Quality

Seven kinds of chemical degradation method of theβ-carotene were studied and the four effective methods were identified eventually.The composition of degradation products and the relative content of components of the four effective methods were analyzed.The application of degradation products in tobacco flavoring of Henan Pingdingshan and Sichuan Huili that in different types of aroma and stalk position was studied The results were as follows:1 In the seven degradation methods,the B-carotene would be degraded in 95%ethyl alcohol effectively by hydrogen peroxide oxidation,catalytic copper sulfate-hydrogen peroxide oxidation,silver nitrate catalyzed oxidation-hydrogen peroxide oxidation and potassium permanganate oxidation catalytic oxidation-hydrogen peroxide oxidation. But it would not be degraded effectively by catalytic silver nitrate-air oxidation, potassium permanganate catalyzed oxidation-air oxidation catalyst and ferric chloride --Hydrogen peroxide oxidation.Hydrogen peroxide oxidation:Taking 95%ethyl alcohol as the medium,making H₂O₂ as the oxidant,then heated to 85℃in water condition,and keeping the temperature for 12h,β-carotene would be degraded effectively.The red suspension became the faint yellow transparent solution and the degradation product（known as A） showed the rich and joyful aroma characteristic.Catalytic copper sulfate-hydrogen peroxide oxidation:Taking 95%ethyl alcohol as the medium,H₂O₂ as the oxidant,sulfuric acid copper as catalyst,then heated to 85℃in water condition,and keeping the temperature for 2h,β-carotene would be degraded effectively.The red suspension became the faint yellow transparent solution and the degradation product（known as B） showed the rich and joyful aroma characteristic.Silver nitrate catalyzed oxidation-hydrogen peroxide oxidation:Taking 95% ethyl alcohol as the medium,H₂O₂ as the oxidant,AgNO₃ as the catalyst,then heated to 85℃in water condition,and keeping the temperature for 4h,β-carotene would be degradated effectively,The red suspension became the faint yellow transparent solution and the degradation product（known as D） showed the rich and joyful aroma characteristic. Potassium permanganate oxidation catalytic oxidation-hydrogen peroxide oxidation:Taking 95%ethyl alcohol as the medium,H₂O₂ as the oxidant,acidic potassium permanganate as the catalyst and the oxidant,then heated to 85℃in water condition,and keeping the temperature for 4h,β-carotene would be degraded effectively.The red suspension became the faint yellow transparent solution and the degradation product（known as F） showed the rich and joyful aroma characteristic.2 The fragrance characteristic of degradation product A performanced for rich clear fragrant and sweet,rose flower fragrance,fruit fragrance and banks rose;Degradation product B fragrance characteristic performance for rich clear fragrant and sweet,dry fruit fragrance and banks rose;Degradation product D fragrance characteristic performance for rich clear fragrant and sweet and flower fragrance;Degradation product F fragrance characteristic performance for rich clear fragrant and sweet,fruit fragrance,banks rose and flower fragrance.The same 14 species volatile ingredients were identified from degradation product A and B by GC/MS and the same 8 species were from degradation product D and F.In all degradation products,the content of dihydroactinidiolide was relatively high,reaching above 40%and the content ofβ-ionone was reaching above 12%.3 The experiment ofβ-carotene Degradation products in tobacco flavoring indicated that the sensory quality of flue-cured tobacco of different aroma type and parts in Henan Pingdingshan and Sichuan Huili changed significantly by adding four different concentrations ofβ-carotene degradation products.When the concentration was 0.1×10^-5,flavoring didn’t take effect obviously and the quantity and volume of aroma, after-taste and offensive didn’t change significantly compared with control.When the concentration was 0.5×10^-5-1×10^-5,the quantity of aroma improved,the volume of aroma increased,the after-taste improved,the offensive reduced and their single and totle scores of smoking were both high,but the irritation almost didn’t reduce.When the concentration was 5×10^-5,the gas incompatible with smoke flavor would be produced,the essence taste was prominent,the offensive and irritation increased and their single and totle scores of smoking were both decreasing.The sensory quality of flue-cured tobacco from different regions and parts was significantly improved by adding the appropriate concentration of fourβ-carotene degradation products.It would increase aroma and mellow and improve after-taste and offensive.The tobacco smoke would be Bulk,refined and reducing dry feeling.To improving tobacco sensory quality,the degradation product A and B resulted basically the same,but A was better than B;the degradation product D and F resulted basically the same,but D was better than F;the degradation product A and B were better than D and F on the whole.