Research On Processing Technique Of Instant Tea Rich In Nature Active Ingredients And Its Products

Instant tea is a tea deep-processing product made from a series of processes using tea or fresh leaves,tea in progress,and tea by-products as raw materials.The traditional instant tea extraction process mainly adopts single-tank,multi-tank extraction methods and counter-current extraction methods.The extraction efficiency is low and the natural active ingredients in the instant tea are lost.In this study,the deep eutectic solution extraction method and subcritical fluid extraction method were used to process instant tea,and the differences between natural tea and instant tea prepared by conventional water extraction method were compared;the single factor of the extraction process were systematically explored for instant tea Influence of natural active ingredients and screening of the best single factor conditions;response surface methodology was used to optimizing the selected single factor conditions and obtaining the optimal extraction process parameters of instant tea that riches in natural active ingredients;scanning electron microscopy?SEM?was used to observe and analyse the extraction mechanism.Meanwhile the antioxidant activity of instant tea rich in natural active ingredients was estimated by comparing free radical scavenging rate of DPPH and ABTS.Buccal tables with the essence of oolong tea and black tea were researched by instant tea rich including natural active ingredients.This research provides a scientific basis for the processing technology and application of instant tea rich in natural active ingredients and the main results are as follows:1.Instant oolong tea rich in natural active ingredients processed by deep eutectic solution extraction?DES?:comparing the effects of 6different deep eutectic solution systems and conventional water extraction methods on the natural active ingredients in instant oolong tea,the optimal deep eutectic solution is selected,which is lactic acid and betaine.Through single factor experiments,the optimal extraction process parameters of instant oolong tea were screened as follows:extraction time40 min,extraction temperature 60?,solid-liquid ratio 1:40 g?m L^-1,deep eutectic solution water content 30%,deep eutectic solvent molar ratio?HBD:HBA?2:1.Continuous variable extraction time?X₁?,extraction temperature?X₂?,and eutectic solution moisture content?X₃?were selected to be optimized by the response surface.The degree affect of three factors is that water ratio of deep eutectic solution?extraction temperature?extraction time.ANOVA analysis of Box-Behnken?BBD?experimental design and response surface methodology?RSM?results:The model P value is less than 0.01,indicating that the experimental model is significant;meanwhile,the mismatch term P value is greater than 0.05?P=0.9691?,demonstrating that the mismatch term is not significant and implying that the model was successfully established;The model's R²=0.9589 and R²_Adj=0.9060,illustrating that the model can reflect the actual situation of the experiment.Combining model and regression equations,the functional relationship between the content of natural active ingredients in instant oolong tea and various factors was analyzed by Design Expert 10.0.7 software:Y=66.65-0.24X₁+0.24X₂ The extraction process parameters of instant oolong tea after optimization by the model were as follow:extraction time 40.5 min,extraction temperature 61.0?,water ratio of deep eutectic solution 31.2%,solid-liquid ratio 1:40 g?m L^-1,HBD:HBA:2:1,the content of natural active ingredients in the instant oolong tea processed by this process is69.23%,which is 57.99%higher than the conventional water extraction method.In summary,the content of natural active ingredients in instant tea processed by the optimized deep eutectic solution extraction method has been significantly increased.2.Instant black tea rich in natural active ingredients processed by deep eutectic solution extraction:comparing the effects of 6 different eutectic solution systems and conventional water extraction methods on the natural active ingredients in instant black tea,the optimal deep eutectic solution is selected,which is lactic acid and betaine.Through single factor experiments,the optimal extraction process parameters of instant black tea were chosen as follows:extraction time 60 min,extraction temperature 50?,solid-liquid ratio 1:40 g?m L^-1,eutectic solution water content 40%,HBD:HBA 1:1.Continuous variable extraction time?X₁?,extraction temperature?X₂?,and eutectic solution moisture content?X₃?were selected to be optimized by the response surface.The degree affect of three factors is that water ratio of deep eutectic solution=extraction time?extraction temperature.ANOVA analysis of BBD experimental design and RSM results:The model P value is less than 0.01,indicating that the experimental model is significant;meanwhile,the mismatch term P value is greater than 0.05?P=0.6286?,demonstrating that the mismatch term is not significant and implying that the model was successfully established;The model's R²=0.9790 and R²_Adj=0.9519,illustrating that the model can reflect the actual situation of the experiment.Combining model and regression equations,the functional relationship between the content of natural active ingredients in instant black tea and various factors was analyzed by Design Expert 10.0.7 software:Y=67.06+1.66X₁+1.45X₂+1.65X₃-extraction process parameters of instant black tea optimized by the model were as follow:extraction time 68.0min,extraction temperature 52.0?,water ratio fo deep eutectic solution 42.2%,solid-liquid ratio 1:40 g?m L^-1,HBD:HBA:1:1,the content of natural active ingredients in the instant black tea processed by this process is 69.03%,which is 156.14%higher than the conventional water extraction method.In summary,the content of natural active ingredients in instant black tea processed by the optimized deep eutectic solution extraction method is significantly increased.3.Instant oolong tea rich in natural active ingredients was processed by method of subcritical fluid extraction:comparing the effects of subcritical water?SWE?,subcritical ethanol solution fluid?SWEE?,and conventional water extraction methods on the natural active ingredients in instant oolong tea,the optimal subcritical fluid was screened which is ethanol solution.Through single factor experiments,the optimal extraction process parameters of instant oolong tea were screened as follows:extraction time 40 min,extraction temperature 130?,solid-liquid ratio 1:40 g?m L^-1,and ethanol concentration 50%.It was selected that variable extraction time?X₁?,extraction temperature?X₂?,solid-liquid ratio?X₃?,and ethanol concentration?X₄?for response surface optimization.The degree influence of four factors:ethanol concentration?solid-liquid ratio?extraction time?extraction temperature.ANOVA analysis of BBD experimental design and RSM results:the model P value is less than 0.01,indicating that the experimental model is significant,and the P value of the mismatch term is greater than 0.05?P=0.1268?,demonstrating that the mismatch term is not significant and implying that the model was successfully established;R²=0.9510 and R²_Adj=0.9020of the model,illustrating that the model can reflect the actual situation of the experiment.Combining model and regression equations analyzing through Design Expert 10.0.7 software,the functional relationship between the content of natural active ingredients in instant oolong tea and each factor:Y=66.85-0.11X₁+0.04X₂+0.36X₃+0.45X₄-0.89X₁X₂-0.92X₁X₃-1.02X₁X4-1.70X₂X₃-1.94X₂X₄-0.63X₃X₄-2.59X₁²-3.33X₂²-1.86X₃²-2.02X₄²;The extraction process parameters of the instant oolong tea are optimized by the model:extraction time 38.1 min,extraction temperature 129.0?,ethanol concentration of 55.0%,solid-liquid ratio of 1:41 g?m L^-1,the content of natural active ingredients in the instant oolong tea processed by this process is 69.53%,which is55.20%higher than the conventional water extraction method.In summary,it shows that the content of natural active ingredients in instant oolong tea processed by the optimized subcritical fluid extraction method is significantly increased.4.Processing of instant black tea rich in natural active ingredients by method of subcritical fluid extraction:comparing the effects of subcritical water,subcritical ethanol solution fluid,and conventional water extraction methods on natural active ingredients in instant black tea,the optimal subcritical fluid is ethanol Solution.Through single factor experiments,the optimal extraction process parameters of instant black tea were screened as follows:extraction time 20 min,extraction temperature 130?,solid liquid ratio 1:40 g?m L^-1,and ethanol concentration 50%.Select variable extraction time?X₁?,extraction temperature?X₂?,solid-liquid ratio?X₃?,and ethanol concentration?X₄?for response surface optimization.The degree of influence of four factors on it is that:ethanol concentration?solid-liquid ratio?extraction time?extraction temperature.ANOVA analysis of BBD experimental design and RSM results:the model P value is less than 0.01,indicating that the experimental model is significant,and the P value of the mismatch term is greater than 0.05?P=0.7114?,indicating that the mismatch term is not significant,indicating that the model was successfully established;R²=0.9510 and R²_Adj=0.9327 of the model,implying that the model can reflect the actual situation of the experiment.Combining model and regression equations analyzing through Design Expert 10.0.7 software,the functional relationship between the content of natural active ingredients in instant black tea and each factor is that:Y=76.03-0.21X₁3.38X₂X₃-2.56X₂X₄-5.39X₃X₄-3.56X₁²-2.00X₂²-4.38X₃²-4.99X₄²;The extraction process parameters of the instant black tea are optimized by the model:extraction time 19.5 min,extraction temperature 130.0?,ethanol concentration of 51.7%,solid-liquid ratio of 1:40 g?m L^-1,the content of natural active ingredients in the instant black tea processed by this process is 78.88%,which is 221.96%higher than the conventional water extraction method.In summary,the content of natural active ingredients in instant black tea processed by the optimized subcritical fluid extraction method has been significantly increased.5.Analysis of the antioxidant activity of instant tea rich in natural active ingredients:comparing the DPPH and ABTS free radical scavenging rates of instant teas prepared by different extraction methods.The IC₅₀of DPPH radical scavenging rates are:instant oolong tea:traditional water extraction method?364.43?g/m L?,DES?312.20?g/m L?,SWEE?225.93?g/m L?,instant black tea:conventional water extraction?364.43?g/m L?,DES?323.29?g/m L?,SWEE?410.08?g/m L?;ABTS free radical scavenging IC₅₀are:instant oolong tea:conventional water extraction?331.58?g/m L?,DES?312.20?g/m L?,SWEE?225.93?g/m L?,instant black tea:conventional water extraction?331.58?g/m L?,DES?323.29?g/m L?,SWEE?410.08?g/m L?.It can be known that the instant oolong tea and black tea processed by the eutectic solution extraction method,and the instant oolong tea processed by the subcritical fluid extraction method have good antioxidant activity.6.Research on buccal table of tea essence rich in natural active ingredients:instant oolong tea and black tea rich in natural active ingredients are used as the main processing ingredients,pineapple powder,flour,mint ice,and aspartame as auxiliary materials,and magnesium stearate as a lubricant,the tea essence buccal tables developed with various ratios of ingredients.The development of instant tea buccal table with multiple ingredient ratios resulted in:instant oolong tea?25%?,pineapple powder?13%?,flour?50%?,mint ice?4%?,aspartame?6%?,and magnesium stearate?2%?;oolong tea extracts made from this proportion have the best test;instant black tea?25%?,neapple powder?24%?,flour?35%?,mint ice?4%?,aspartame?10%?,and magnesium stearate?2%?;the black tea essence buccal table made from this proportion is optimal.