Research On Development Of Ultrafine Green Tea Powder Effervescent Tablet

Green tea is one of the most popular drinks in the world.The fresh leaves of tea tree have gone through the process of fixing,rolling,drying,primary preparation and sterilization.Then the green tea was ultrafine grinded into ultrafine green tea powder,which can keep the original color,flavor,quality and various natural ingredients of green tea as much as possible.Effervescent tablet is a novel tablet in recent years,which is convenient to carry and instant to drink.It can meet people's demand for efficient,portable and novel food products when it is applied in food.The development of ultrafine green tea powder effervescent tablets which combine ultrafine green tea powder and effervescent tablet can provide reference for the deep process and comprehensive utilization of green tea.1.Ultrafine green tea powder was prepared by grinding green tea powder roughly and the ultrafine grinding with different time.The roughly grinding green tea powder and ultrafine green tea powder were observed by scanning electron microscopy.The particle size,release of polyphenols,antioxidant activity and sensory evaluation were determined.Results are as follows:(1)After ultrafine grinding,the median particle size of roughly grinding green tea powder decreased from 238.33 ?m to about 20 ?m.The uniformity of particles gradually increased,and the fluidity decreased.(2)The release of polyphenols of ultrafine green tea powder was significantly higher than that from roughly grinding green tea powder.The polyphenols release rate of the green tea ultrafine grinded for 5 min was the fastest,and first reached a stable state.There was no significant difference in the final polyphenols release content of green tea powder with different ultrafine grinding time.(3)The DPPH free radical scavenging activity of ultrafine green tea powder was significantly better than that of roughly grinding green tea powder.The activity of scavenging ·OH free radical and total deoxidization activity had no significant difference after extraction for a period of time.The antioxidant activity of green tea powder could be improved by ultrafine grinding.(4)The sensory evaluation results showed that the green tea powder with ultrafine grinding for 10 min had the highest favorability,while the green tea powder with roughly grinding had the lowest favorability.(5)There was no evidence that the longer the ultrafine grinding time,the better the characteristics green tea powder would get.After ultrafine grinding for 10 min,the green tea powder had the best scavenging activity of DPPH free radical,the best sensory evaluation,and good release condition of polyphenols.Therefore,it is suitable to be used as the raw material of ultrafine green tea powder effervescent tablet for further research.2.The formula of ultrafine green tea powder effervescent tablet was selected and optimized by sensory evaluation.The acid source,alkali source,acid-base ratio,sweetener and filler were determined.Then,the addition amount of tea powder,disintegrating agent and sweetener were used as variables for single factor test.Finally,Box-Behnken response surface optimization with three factors and three levels was carried out on the basis of single factor test to determine the formula and then the formula was verified.Results are as follows:(1)Citric acid and sodium bicarbonate(1.4:1,w/w)were selected as a disintegrating agent.Aspartame was used as sweetener and mannitol was used as a supplement.(2)The Box-Behnken response surface optimization shows the order of influence the selected factors on the response value was sweetener amount>ultrafine green tea powder amount>disintegrating agent amount.The predicting optimal formula was9.44% ultrafine green tea powder,43.79% disintegrating agent and 1.78% sweetener.3.According to the optimized formula,the ultrafine green tea powder effervescent tablets were made by two processing method: Direct Compression and Wet granulation Method.The quality of effervescent tablets was evaluated by measuring the moisture content,hardness,friability,tablet weight,tablet thickness,foaming amount,disintegration time and p H.A simulated in vitro digestion model was established to simulate stomach and intestine digestion stages.The antioxidant activity,the polypenols release content and soluble proteins content before and after digestion were determined to evaluate the digestive characteristics of ultrafine green tea powder effervescent tablets.Results are as follows:(1)The effervescent tablets using the Direct Compression had lower friability,larger foaming amount,shorter disintegration time and lower p H.The effervescent tablets made by Wet granulation Method had lower moisture content and higher hardness.(2)Simulated stomach digestion increased the polyphenols release content of the effervescent tablets.The release content of Direct Compression tablets and Wet granulation Method tablets increased from 16.10 mg/g and 12.91 mg/g before digestion to the maximum 20.67 mg/g and 20.16 mg/g,respectively,and the content in the simulated intestinal digestion stage was decreased.(3)The antioxidant activity of two kinds of effervescent tablets changed in the same trend during simulated in vitro digestion.The total deoxidization activity was improved,the scavenging activity of DPPH free radical was decreased,and the scavenging activity of ·OH free radical was stable.Antioxidant activity of Direct Compression effervescent tablets was higher than Wet granulation Method tablets.(4)Simulation in vitro digestion significantly increased the soluble protein release content.The release content of Direct Compression tablets and Wet granulation Method tablets during digestion increased from 4.17 mg/g and 3.83 mg/g to 10.13mg/g and 8.47 mg/g,respectively.