Studies on the microwave-assisted extract of freshwater clam and its biochemical characteristics
| Autor: | Ko, Tzu-Yin, 柯姿因 |
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| Rok vydání: | 2015 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 103 In recent years, freshwater clam essence products are very popular in domestic health food market. It is generally recognized that freshwater clam essence has liver-protecting effect. Hot water extract of fresh water clam and freshwater clam essence can reduce pig and rat liver damage caused by alcohol and carbon tetrachloride. Microwave-assisted extraction method applies microwave-assisted heating solvents and matrix to accelerate the entire process. This method significantly reduces the consumption of solvent extraction and improves the efficiency much better than the conventional solvent extraction. The objective of this research is to explore the optimal procedure of producing freshwater clam essence by using microwave-assisted extraction (microwave-assisted extract optimal conditions; MAEO), moreover, to compare MAE freshwater clam essence to steamed freshwater clam essence and commercial freshwater clam essence. MAE freshwater clam essence at ethanol content 10%, power 600 W extraction for 10 minutes led to the highest glycogen content. MAE freshwater clam essence and steamed freshwater clam essence had similar proximate composition, pH value, and NH3 content. The appearance of commercial freshwater clam essence is whiter, steamed freshwater clam essence is more beige; however, MAE freshwater clam essence is darker and has higher turbidity. MAE freshwater clam essence has relatively higher contents of potassium, zinc, and phosphorus, steamed freshwater clam essence is lower and commercial freshwater clam essence is the lowest one. The methylmercury, cadmium and lead contents are all sub-standard. Moreover, steam freshwater clam essence and MAE freshwater clam essence have lower sodium content. The antioxidative activities of steamed freshwater clam essence and MAE freshwater clam essence are higher than commercial freshwater clam essence. Also, MAE freshwater clam essence has higher free amino acid content. Overall, MAE freshwater clam essence has a better extraction efficiency which can lower processing time from 35 minutes to 13.5 minutes, and it has higher glycogen, total free amino acid and peptide content. However it is more smelly and it has lower acceptance in sensory evaluation. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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