Research on Properties of Ginkgo biloba Powder by Different Drying Methods
2009, 43 (6):
Due to different drying type in Ginkgo biloba (GB) seed, properties of GB seed powder have some difference. In this research, GB seed was dried by spray drying(SP) and freeze drying(FD). Then each advantage was indicated by comparison between properties of GB powder, i.e., moisture content, mean particle size, color difference, protein content. In pilot spray drying, it was performed under the following conditions, i.e., air flow rate at 120 m3/h, feed concentration at 8%, inlet air temperature at 205℃, outlet air temperature at 100℃ and atomizer rate at 3200 r/min. In freeze drying, GB seed feed was frozen at -40℃ for 4 h, it was dried under the vacuum of 300 Pa for 48 h. It was found that moisture content, mean particle size, color difference, protein content were SP<FD, SP<FD, SP<FD and SP<FD, respectively. The measured results showed that spray drying would provide the dried GB seed powder in low moisture content and small mean particle size, however their color was whiter and their protein was destroyed badly. On the other hand, the dried product via freeze drying had high moisture content and large mean particle size, however their color could keep the color of raw material and their protein content was higher than that by spray drying. From those mentioned above, it was known that spray drying was selected if GB seed powder of low moisture content and small particle was required, and freeze drying was chosen if GB seed powder of high nutrition and born color was required.
Related Articles |