Effect of osmotic dehydration on the quality of air-dried Porphyra
Osmosis with a solution of NaCl and sucrose to depress the water activity (aw) to 0.970 and the pH to 3.0 was assayed as a pretreatment to air-drying of red seaweeds (Porphyra columbina Montagne). Air-drying was performed at 30°C and 14% relative humidity. Process characteristics, color, flow patter...
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| Autores principales: | , , , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00236438_v36_n4_p415_ValenciaRodriguez |
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| Sumario: | Osmosis with a solution of NaCl and sucrose to depress the water activity (aw) to 0.970 and the pH to 3.0 was assayed as a pretreatment to air-drying of red seaweeds (Porphyra columbina Montagne). Air-drying was performed at 30°C and 14% relative humidity. Process characteristics, color, flow pattern and rehydration ability of the milled product, were evaluated to determine the usefulness of osmosis. The aw attained after 2 h of drying was similar for both osmosed and nonosmosed Porphyra and higher than monolayer water activity for both products. Consequently, no additional benefits concerning stability during storage were observed, after applying osmosis. Moreover, severe changes in color occurred. Powder flowability evaluated through the measurement of compressibility and cohesiveness decreased with pretreatment, which also determined a more plastic behavior. In summary, osmotic dehydration as a pretreatment for air-dried seaweeds did not seem to improve the final product quality. © 2003 Swiss Society of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved. |
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