Optimization of Extraction Process of Tea Polyphenols from Maocha Tea and Its Effect on Quality of Fresh-Cut Apples

Using the content of tea polyphenols as the index,the optimal extraction process of tea polyphenols in Maocha was optimized by response surface test,and freshly cut apples were soaked with Maocha extract with tea polyphenol content of 0,2,4,and 8 mg/mL. The fresh-keeping effect on fresh-cut apples was evaluated by ΔE,weight loss rate,hardness,titratable acid content,soluble solids and sensory evaluation. The experimental results showed that the optimum conditions for extracting tea polyphenols from Maocha were as follows:Extraction time 65 min,extraction temperature 55 ℃,ultrasonic frequency 65 kHz. Under this condition,the content of tea polyphenols in the extract was 19.312 mg/g. The results of the treatment of fresh-cut apples with Maocha tea polyphenol extract showed that it could reduce the weight loss rate and hardness of fresh-cut apples,and also also delay the decline of titratable acid and soluble solids in fresh-cut apples,and better maintain the sensory quality of fresh-cut apples,4 mg/mL of Maocha tea polyphnol extract could preserve fresh-cut apples well.