Research of the freeze drying curve of the instant tea freeze drying

The optimum technology condition of the instant tea freeze drying was introduced and the basic data for commercial production of instant tea powder was showed in this article.The tea extraction became the tea powder by removing water in the extraction with freeze drying.Some of the factors which the tea powder moisture content was affected were studied, such as the extracted liquid concentration, the thickness of tea extraction in the freeze drying equipment, freezing and heating temperature and drying time.The freeze drying curve was built and the optimized freeze drying condition was obtained:the extracted liquid concentration was 20% ~ 25%, the thickness was 10mm, freezing temperature was-17℃, drying time was 8.5h, and the pressure was 0.1⁰.3mmHg.