Abstract
Drying causes many chemical and physical changes in plant tissue. Physical changes are mostly due to stresses developed in the tissue and are pronounced by macro- and microalterations of size, shape and internal structure. The extent and direction of these changes depend on the mode of drying. Convective drying of apple tissue results in numerous breaks of cell walls and formation of many microcavities. In consequence, the dominating cross-sectional area of cells moves toward values smaller than those observed in raw apple. Cavities formed during convective drying can be pictured in 2D plane as pentagons joined together or ellipses with large ratio between axes. Puff-drying forms porous structure with cavities twice as large as in raw apple. The process homogenizes the structure, and spread of cell sizes is even smaller than that observed in raw apple. Broken cell walls are clearly visible in microphotographs of sliced samples. Many large cavities with cross-sectional area exceeding 40,000 µm2 are characteristic of puff-dried apple while such areas are hardly found in raw apple. The structure of freeze-dried apple is similar to that formed during puff-drying. Large irregular cavities and broken cell walls are clearly seen in microphotographs. However, larger cavities are present in freeze-dried apple than in puff-dried one. Cross-sectional area of cavities in freeze-dried apple can be simulated by pentagons joined together or elongated ellipses.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.