Study On Degreasing And Deodorizing Technology And Influence To Quality Of Cultured Pseudosciaena Crocea Richardson

Pseudosciaena crocea is a kind of drum fish. The meat of Pseudosciaena crocea is delicate and delicious, which has high protein content and low cholesterol content. It is also good for treating anemic and body health. Thus Pseudosciaena crocea becomes one of the best edible fish in marine fish, which is deeply liked by many consumers around the world. But in recent few years, due to arbitrarily catching, Pseudosciaena crocea resources declined severely. To protect the resource of Pseudosciaena crocea, the aquatic scientists have researched for many years. The yield of farmed Pseudosciaena crocea has increased continuously, in Zhejiang and Fujian mindong coastal area.In order to lower the fat content, reduce the fishy smell, and improve the fish meat quality of the farmed Pseudosciaena crocea, this study aims at the problems of high fat content and strong fishy smell of farmed Pseudosciaena crocea and research the degreasing and deodorizing technology. The study mainly analysis the process of degreasing technology by Na2CO3 and NaHCO3 and enzyme for Pseudosciaena crocea, and the change of volatile organic compounds and structure through handling deodorization combined with NaHCO3 and NaCl, sensory evaluation, to provide the theory basis for making a performance optimization in deodorization.Pseudosciaena crocea contains a lot of fat, and wet basis is 15.6%, while dry basis reached 56.1%, which is far more than the wild Pseudosciaena crocea content. The best degreasing method of Na2CO3 is liquid concentration of 6g/100mL, marinating time of 90min, fish and water marinating proportion of 1:2, skim rate of 41.18%; the best degreasing method of NaHCO3 is liquid concentration of 0.5g/100mL, marinating time of 60min, fish and water marinating proportion of 1:2, skim rate of 45.69%;The best degreasing method of enzyme is concentration of 40U/mL, pH8.0, marinating time of 30min, fish and water marinating proportion of 1:3, skim rate of 44.89%. Considering skim rate and production conditions, the best degreasing method is using NaHCO3.The combination of 0.5g/100mL NaHCO3 and 10g/100mL NaCl were used as the mixing deodorization liquid to breed Pseudosciaena crocea. Sensory evaluation showed that the fishy smell weared off as the concentration of salt increased. After processing, the fishy smell, metallic taste, earthy taste, mushroom taste and unpleasant fat smell of Pseudosciaena crocea had basically been removed. It is clear that NaCl played a synergistic role in the process and improved the meat quality and flavor of Pseudosciaena crocea. It not only reduced the fat effectively, but also promoted precipitation of the composition of fishy smell.As a result of choosing fiber, time, temperature and desorption time, we can know the best condition for culturing Pseudosciaena crocea on SPME fibers is extracting in 60℃and 30min, desorbing in 5 minutes by CAR/PMS. There are 48 compositions detected, of which the main component are carbonyl compound and alcohol. The processed yellow fish contains 19 components. Raw taste has been mainly caused by 2,4-Decedienal, hexaldehyde, 1-Penten-3-one, 3,5-Octadien-2-one, 1-Penten-3-ol, and 1-Octene-3-ol.There are obviously differences between Pseudosciaena crocea treated by NaHCO3 process and mixet salt combination treatment. The composition of fishy smell and substance which played the synergy role was greatly reduced. The fishy smell, metallic taste, earthy taste, mushroom taste and unpleasant fat smell of Pseudosciaena crocea contributed by alcohols, ketone and aldehyde compounds had basically been removed. GC-MS results showed that the changes of smell caused by the changes of volatile components in cultured Pseudosciaena crocea were consistent with the sensual evaluation results. It showed that mixet salt combination is a kind of effective skim deodorization processing method.Through the analysis of quality and structure of Pseudosciaena crocea by instrument TPA mode, from hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness, resilience, the parameters result show that degreasing and deodorizing do not affect the character of Pseudosciaena crocea.