科研之友
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摘要
The effect of air drying temperature on physical properties of dried Fucus vesiculosus seaweed and the antiradical capacity and composition of its aqueous extracts were studied. Air drying was performed in a tray dryer employing different temperatures (35, 40, 60 and 75 degrees C). Dried seaweed (12.2 g water (100 g)-1 dry solid) was milled and particle size characterization and colour analysis of obtained powder were performed. Seaweed powder dried at different temperatures showed significant differences regarding colour properties. Lower brightness and yellowness values were determined in samples dried at 50 and 60 degrees C in comparison to those dried at 35 degrees C; greenness at 50 degrees C was enhanced. Nevertheless, particle size distributions of powders were invariant with drying temperature. Dried seaweed powders (< 500 mu m) were subjected to ultrasound-assisted aqueous extraction (for 4 min and liquid/solid ratio of 30). Total polyphenol content and antioxidant activity (using DPPH center dot radical scavenging activity) decreased with increasing drying temperature. A linear relationship between both properties was found. Extracts obtained from seaweed dried at 35 degrees C and sieved to obtain several particle size fractions showed that the maximum polyphenol content was achieved with the intermediate size fractions (80200 mu m). High drying temperatures had a positive effect on alginate extraction yield, but carbohydrate content was not affected (both content referred to raw seaweed powder).
- 出版日期2016-8
