碩士 / 國立臺灣海洋大學 / 食品科學系 / 106 / The purpose of this study is to analyze proximate compositions, free amino acids (FAA), minerals, trace elements and heavy metals in edible seaweed samples. They were 6 kinds of red seaweed and brown seaweed, and 2 kinds of green seaweed samples which were collected from the market. There are significant differences in proximate composition among seaweeds. The moisture in 14 kinds of seaweed ranged from 7 to 44%¸ ash 2 to 28%, and crude protein 2 to 28%. Trace amounts of crude lipid were found in all samples. The pH value in the seaweed products was between 5.78-10.21. Red seaweed was in a weakly alkaline ranged from 6.67 to 10.21, and brown and green seaweed were in a weakly acidity from 5.78 to 7.00. Some seaweeds had much higher pH value. It might due to wash and clean seaweeds with alkaline solvent during processing. There is remarkable difference in the content of free amino acid (FAA) among species. Saccharina japonica and Durvillaea antarctica had high levels of FAA with 1716-2671 mg/100g, but those of Eucheuma denticulatum, Eucheuma serra and Undaria pinnatifida were lower than 100 mg/100 g. Porphyra dentata had more kinds of FAA among samples. Brown seaweeds possessed higher amounts of aspartic acid, glutamic acid and alanine. For Ulva lactuca, it had much more taurine than any other seaweeds. There is remarkable difference in the contents of minerals in seaweeds. The amount of sodium ranged 706-91975 ppm, potassium 991-88191 ppm, calcium 1847-29453 ppm, and magnesium 1170-37915 ppm were found in seaweeds. For the trace elements in the seaweed products, the amount of iron was 36-927 ppm, manganese 0-5.76 ppm, chromium 0-0.04 ppm, copper 0.8-21.4 ppm, and zinc 1.28-23.13 ppm. The amounts of trace elements showed significant difference in different species of seaweeds expect for chromium. Even the same species of Ulva lactuca, the contents of iron and manganese in different samples also showed remarkable difference. There was 3.46 ppm of lead in Gelidium amansii, but other seaweeds has less. The average amount of lead in red seaweed was higher than those of brown and green seaweed. According to food sanitary standards, all samples meet the regulation limit as calculated the moisture of seaweed with 85% of moisture such as fresh one. Cadmium was found in samples, but all are under the limit. The contents of mercury ranged from 0.02-0.04 ppm which was in compliance with the limit. The high levels of aluminum were found in Gelidium amansii (809 ppm), KappapHycus alvarezii (461 ppm) and PorpHyra dentate (357 ppm). The use of aluminum as leaveners in those seaweeds may result in high levels of aluminum in the products. The amount of arsenic in the seaweed products was between 0.84-46.36 ppm. Inorganic arsenic As2O3 and NaAsO3 of the samples do not exceed the regulation limit 1 ppm after converting the moisture of seaweed to 85%. The results could provide the information regarding basic nutrient substances, flavor compounds, trace elements, minerals and heavy metals in seaweeds. It also could be a reference for consumers to purchase edible seaweed and for government agency to set the limit standard of seaweed.
| Identifer | oai:union.ndltd.org:TW/106NTOU5253002 |
| Date | January 2017 |
| Creators | Chiao, Pi-Ying, 焦碧瑩 |
| Contributors | Shiau, Chyuan-Yuan, Nan, Fan-Hua, 蕭泉源, 冉繁華 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 57 |
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