| Summary: | 碩士 === 國立臺灣海洋大學 === 食品科學系 === 94 === The proximate composition and heavy metals of cultured oysters collected from Dong-Shi, Chia-Yi and other regions of Taiwan were analyzed. Seasonal and regional differences of heavy metal contents and their sanitation compliances were also studied.
The gross weight of oysters reached peak in summer. Oysters from Ma-Tzu area weighed heavier than those collected from Taiwan island. The moisture content of Dong-Shi oysters ranged from 81.7 to 87.9%, protein 6.01∼10.3%, lipid 0.76∼2.14%, ash 0.80∼2.64% and carbohydrate 1.72∼7.02%. As compared to Dong-Shi oysters, Keelung oysters contained higher moisture content, possibly long time soaked in water in local market. Ma-Tzu oysters had higher ash (2.09~3.09%), protein and sodium contents.
Reference standards of heavy metals were used to confirm the accuracy and consistency of the method used in detecting heavy metal contents of oysters. The correlation coefficient of the standard curve is 0.99 to 1.00, indicating the linear relationship between the concentration and absorbance of reference standard. Among 36 samples, the highest concentration in each kind of heavy metal was shown as following: Zn: 240.83 ppm, Cu: 312.10 ppm, Pb: 2.96 ppm, Ni: 1.29 ppm, Cd: 1.41 ppm, Cr: 0.50 ppm, As: 0.55 ppm, Hg: 0.18 ppm. These figures showed there was no hazard concern of heavy metal in oysters of Taiwan when compared with domestic and international sanitation standard. Some oyster samples contained higher amount of zinc and cupper, especially in those collected on February and March. In General, oysters sampled from Yuan-Lin and Ma-Tzu had higher contents of heavy metals than those of Chia-Yi and Tainan.
|
|---|
