| Summary: | 碩士 === 國立臺灣海洋大學 === 食品科學系 === 98 === The objective of the study was to compare the growth rate and bioactive substances (fatty acids, sterols, chlorophyll and total carotene) of freshwater clam (Corbicula fluminea) fed with commercial feed, commercial microalgae powder, pure Chlorella pyrenoidosa isolated from the clam culture pond. After feeding for month, the growth rates of freshwater clam fed with freshwater microalgae was significantly higher than those fed with marine microalgae, which significantly decreased the growth rate of clam. Regardless of the season, the unpulverized freshwater microalgae (UFM) fed to clam increased the body weight and reduced the mortality rate. The content of chlorophyll in UFM was significantly higher than the pulverized freshwater microalgae. The clam fed with UFM also had higher chlorophyll content (2.62g/g) than clam fed with feeds ranging 2.09 t0.77 g/g. The origin, species and size of microalgae fed to clam affected the content of chlorophyll and total carotene in freshwater clam. The main fatty acids of microalgae were polyunsaturated fatty acids (PUFA) (41.05-48.69% lipid), the commercial feed had the lowest content of PUFA (29.18% lipid), and the clam fed on it also had the lowest PUFA (22.65% lipid). The marine microalgae and clams fed on it had the highest content of EPA. Therefore, clam composition of fatty acids was changed by feeds. The major fatty acid in clams were C16:0 (30.14-35.35% lipid), C16:1 (11.70-13.11% lipid) and C18:1 (7.86-8.48% lipid). The sterol in UFM was squalene、ergosterol、campesterol、cholesta-5,7-dien-3-ol、brassicasterol.
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