Studies On Heat-pressure Shucking And Quality Contril Technology For Mussels

Due to the rich resources of mussels in China,mussel products have been sold domestically and overseas for a long time,and most of mussels need shuck before sold into the markets.Due to the low efficiency and meat quality of traditional water boiling shucking method,the heat-pressure shucking and brine separating meat from shell method were used for mussels in this thesis.The effect of them on shucking and separating meat from shell,the shucking mechanism of thermal treatment,the dried characteristics of mussel,and the quality control were studied.Main results were showed as follows:1.Heat-pressure and brine have obvious impacts on meat quality,heat-pressure increased the loss of water soluble substances and textural quality,brine led meat to higher salinity.Compared with water boiling,heat-pressure in 140,145,150? displayed advantages in shucking rate and structure quality,especially in the temperature of 145 ? with 1 min.Brine concentration 10% with 10 min achieved better shucking effect and lower salt content and microbial growth.2.Adductor muscle changes were studied to explore the shucking mechanism of heat-pressure.The results showed that after dealing with the above 140 ? heat-pressure steam,the actomyosin and collagen of adductor muscle produced significantly difference in water boiling degeneration.Specific performance in the results of SDS-PAGE(sodium dodecyl sulfate-polyacrylamide gel electrophoresis)showed the belt of myosin light chain and heavy chain disappeared.Infrared spectrum showed the non-covalent bond of its protein tertiary structure ruptured,the protein of adductor muscle in mussels was gelled.Collagen in connective tissue change to gelatin in the glass transition temperature,the results of DSC(differential scanning calorimetry)showed that the glass transition temperature is about 134?.Electron microscope observation found that the adductor muscle protein spherical scattered when untreated,after thermal treatment in combination with the gel can produce better than boiled processing,therefore,achieve the purpose of better effect in breaking away the adductor muscle from the shell.3.Composite phosphates were used to improve the quality of the water holding capacity and texture of shucked meat.The results of RSM(response surface methodology)showed that optimum adding concentration of TSPP(tetrasodium pyrophosphate),STPP(sodium tyipolyphosphate),SHMP(sodium hexametaphosphate)was 0.36%,0.3% and 0.28%,respectively,the composite phosphate treated 20 mins could not lead to phosphate excess.At the same time,adding 0.01% BHT can restrain dried meat to oxidation with lower AV and TBA value.4.Heat pump drying with different temperature and wind speed was used to study the drying process of mussel meats,the Page model was suitable for the dehydration model.The quality change of mussel meats in the process of drying was also study,the protein fiber of mussels contracted in the process of drying which made the increase of elasticity and hardness of meat tissue.TBA value showed that lipid oxidation was increased at the beginning of drying period and then slowed down.The flavor compounds changed accompanied by the protein and lipid changes.Therefore,the unique flavor was formed in mussel meats.The delicious amino acid increased which make the meat taste freshly,the changes of volatile odour compounds eliminated the sea fishy smell and formed the unique fragrant odours for dried mussel meats.The color of dried mussels presented deeper brown than before.