| Recently the oyster products are increasing rapidly. It has become an important means of promoting development to high-valuably utilize oyster in oyster industry. Oyster polysaccharide is one of important active substances. It can be processed as health food and drug, which were valuable deeply processing products. Therefore it is necessary for industrialization exploitation of oyster polysaccharides. To achieve this objective, reasonable processing flow should be designed. In this study, water-soluble polysaccharides were isolated from Crassostrea gigas by hot-water extraction, isoelectric precipitation, and ultrafiltration instead of traditional alcohol precipitation. And the yields of oyster polysaccharides in one year were investigated. Then the 1000 kg/a oyster polysaccharide production workshop was designed on the basis of these results. Specific studies are as follows:1. Two processes of hot water extracting and isoelectric point precipitating protein were investigated. Single factor test was used to analyze the influence of each factor such as extraction temperature, time, times and solid-liquid ratio. The optimal conditions for extraction were studied by L9(34) orthogonal experiment design. The results of orthogonal test showed that the optimal conditions for extraction of polysaccharides from C. gigas were as follows: temperature 90 °C, extraction time 5 h, extraction times 4, solid-liquid ratio 1:20(w/v). In the process of isoelectric precipitation the most suitable p H value was 5.1.2. In order to separate the polysaccharides from C. gigas using ultrafiltration membrane, the molecular weight distribution and process of CGPS were studied. Results indicated that ultrafiltration membrane with molecular weight cut off 10 k Da was used, which flux was better. The CGPS cut off by the membrane has molecular weight with 1.2×103 k Da, and the permeate liquor has molecular weight with 4.4 k Da. The orthogonal tests showed the main factors of effect were temperature of solution and operating pressure, while p H had less influence. On consideration of the life of membrane and production costs, the optimum technology of ultrafiltration are temperature 30℃, operating pressure 0.04 MPa and p H 7.0.3. Oyster polysaccharides had been produced for 1 year. The total production batches were 47, and the average period was one week. The total consumption of oyster(wet weight, without shell) was 1180 kg. 7152 g oyster polysaccharides were produced, accounting for 0.6% of total weight. The results of oyster polysaccharides yields of each month in one year showed that the yields of oyster polysaccharides from January to June were significantly higher than that from July to December. The main chain of oyster polysaccharide is consisted of glucan linked with α-glycosidic bond.4. Finally, production workshop with an annual output of 1000 kg oyster polysaccharides was designed. The main contents were the workshop graphic design; material balance; equipment selection; water and electricity estimation; analysis of organization management and labor force. For the formulation of oyster polysaccharides, the corresponding food safety enterprise standard was established and successfully recorded. The technology and economy were analyzed. In this project, the total investment was 33.08 million RMB. The results of financial analysis showed that profit rate is very high. The profit rate of investment and sales are 45.09% and 16.6%, respectively. The payback period, The breakeven point and safe operation rate were 2 years, 220.39 kg and 61.6%, respectively. Economic benefits were good. Two CAD drawings were designed, which were process flow diagram and workshop plans, respectively. |
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