Partial Freezing Of Freshwater Fish And Research Of Its Processing Technology

Crucian fish, after being slaughtered and washed, were dipped in 0.1% tea polyphenols (TP) solution (0.08% water-soluble and 0.02% lipid-soluble TP) for 1 h at 3°C, packed in 0.013 mm polyethylene film, and then stored in -3℃ for partial freezing. Indicators including sensory assessment, trimethylamine (TMA), pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid test (TBA) values and bacterial counts were used to evaluate the fish quality. Results indicated that TP could significantly restrain bacteria growth, lower TVB-N and TBA values, and delay the decline of sensory score. However, there were no significant effects of TP on TMA and pH values. In summary, TP has effective effects on inhibition of bacteria growth and anti-oxidation of fat, and thus significantly delay the spoilage of partial-frozen Carassius auratus.10%NaCl solution was used as blank test sample (CK), 2:l:2gralic: ginger: onion were blended and crushed into paste, then 13:5:2 paste : distilled water: sodium chloride were blended as marinade. After dissecting, head cutting, cleaning, and leaching, the silver carp was taken samples by AOAC analytical method, one part proceed to be measured the water capacity of fresh sample, crude fat, crude protein, crude ash content, TMA,PH,TVB-N and TBA;The rest were soaked into blank test sample and marinade respectively. The weight of fish sample and marinade were equal, and the temperature of marinading were retained 3 + l℃,15d later measured the water capacity, crude fat, crude protein, crude ash content ,TMA,PH,TVB-N and TBA, sodium chloride ,sensing of the fish sample from different marinade. The results showed that the basic chemical composition of pickled carp in contrast with fresh sample had changed except the water capacity. The crude fat, crude protein, crude ash content and NaCl had increased evidently, PH reduced obviously, both TBA and TMA value had increased evidently ,TVB-N basically held the line.The water capacity, crude fat, crude protein, crude ash content and NaCl of treated sample were very close to the blank test sample's.Sensory grade,TMA ,pH ,TVB-N and TBA were lower than blank test sample's ,but the difference was in-apparent;The impact on froze pickled carp's TMA, pH, TVB-N and TBA was limited.Yunhe lake has abundant fishery resource .However, little fish such as Culter erythropterus,Hemiculter leucisclu are apt to die owing to short fuse. In the experiments, they were preserved via dehydration, vacuum packaging, deep fry and bake. The water capacity was reduced effectively, he flavor was enhanced, the shelf life was extended after above treatment and process, meanwhile obviated the disadvantage of small transporting radius and increased additional value, moreover, it made the little fish easier to eat and circulate, which can join manufacturing, supply, distribution very close and greatly promote the Yunhe lake fishery.