2019年12月
Continuously Distributed Glass Transition of Maca (Lepidium meyenii Walpers) Powder and Impact on Caking Properties
FOOD BIOPHYSICS
- ,
- ,
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- 巻
- 14
- 号
- 4
- 開始ページ
- 437
- 終了ページ
- 445
- 記述言語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1007/s11483-019-09593-z
- 出版者・発行元
- SPRINGER
Water sorption isotherm, glass transition temperature (T-g), and caking properties of maca (Lepidium meyenii Walpers) powder were investigated. A broad endothermic shift reflecting continuously distributed glass transition was detected by differential scanning calorimetry, which prompted the evaluation of onset T-g and offset T-g. From the onset and offset T-g curves and water sorption isotherm, critical water activity (water activity at glass transition temperature of 25 degrees C) was determined to be 0.258 for the onset T-g and 0.480 for the offset T-g. The critical water activity values were validated by isothermal mechanical relaxation measurement. Caking properties of maca powder were compared with maltodextrin. The degree of caking and cake hardness for maltodextrin increased at a water activity just above critical water activity for onset T-g. Maca powder, on the other hand, showed a small degree of caking in the water activity range of 0.225 to 0.576, and the degree of caking drastically increased at a higher water activity. The hardness of maca cakes increased gradually at water activity values greater than 0.432. Since maca powder showed a continuously distributed glass transition, the molecular mobility required for caking was considered to have been provided incrementally by the increase in water activity above critical water activity for the onset T-g.
- ID情報
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- DOI : 10.1007/s11483-019-09593-z
- ISSN : 1557-1858