| With the improvement of people’s living standard,people’s demand for aquatic products is increasing.All kinds of fish food is nutritious and delicious.They can provide a large number of high quality animal protein for human.Because the water content is high,the death of the quality change speed is so fast.It is easy to cause spoilage of fish because of the effects of enzymes and microorganisms.In this paper,the changes of the quality of the frozen storage and the process of cold storage were studied from two aspects of packaging materials and biological preservatives.For it can provide theoretical basis for the preservation of fish.The samples(Scomberomorus niphonius or Trichiurus lepturus)were packed with PVDC,polyethylene or composite bag(PP/PE/nylon),and stored at the temperature of-18℃.PH,TVB-N,salt soluble protein,histamine,TBA,texture and sensory indexes were measured for the fish(with internal organs or without internal organs).The effects of different biological preservatives quality during storage of the samples can be studied;Scomberomorus niphonius(Alaska Pollock)as samples were made into recuperation fillet(blank/nisin/natamycin),packaged with PVDC packaging materials.Under the temperature of 4℃ for storage,pH,TVB-N,salt soluble protein,histamine,TBA,texture and sensory indexes-were measured for the recuperation fillet.determination of pH,TVB-N,histamine,coliforms,total number of colonies and sensory indexes.The effects of different biological preservatives quality during storage of the samples can be studied.During the frozen storage period of 0～360d,the hardness,chewiness,springiness,cohesiveness,salt soluble protein,TBA,histamine and TVB-N value of Scomberomorus niphonius or Trichiurus lepturus were determined.The hardness,chewiness,springiness,cohesiveness and salt soluble protein of the three kinds of packaging materials were decreased in different degrees during the storage period of 0～360d,and the TBA and histamine in 360D did not exceed the national standard.These results indicate that the effect of PVDC packaging materials is the best.On 360d,The TVB-N value was 22.79mg/100g of Trichiurus lepturus with internal organs and the TVB-N value was 25.51mg/100g of Trichiurus lepturus without internal organs in the PVDC packaging material.On 230d,The TVB-N value was 29.49mg/100g of Trichiurus lepturus with internal organs and the TVB-N value was 29.39mg/100g of Trichiurus lepturus without internal organs in the polyethylene packaging material.The TVB-N value was 30.40mg/100g of Trichiurus lepturus with internal organs on 180d and the TVB-N value was 28.50mg/100g of Trichiurus lepturus without internal organs on 200d in the composite.bag(PP/PE/nylon)packaging material.Thus,the shelf life of the frozen Trichiurus lepturus in the polyethylene packaging material is 230d,in the composite bag packaging material is 180d,and in PVDC packaging materials in 360 d is still not beyond the limited value in our country.The TVB-N value was 28.50mg/100g of Scomberomorus niphonius with internal organs on 200d and the TVB-N value was 30.00mg/100g of Scomberomorus niphonius without internal organs on 260d in the PVDC packaging material.On 230d,The TVB-N value was 29.50mg/100g of Scomberomorus niphonius with internal organs and the TVB-N value was 29.49mg/100g of Scomberomorus niphonius without internal organs in the polyethylene packaging material.The TVB-N value was 29.49mg/100g of Scomberomorus niphonius with internal organs on 200d and the TVB-N value was 28.48mg/100g of Scomberomorus niphonius without internal organs on 230d in the composite bag packaging material.Thus,the shelf life of the frozen Scomberomorus niphonius with internal organs in the polyethylene packaging material is 200d,in the composite bag packaging material is 230d,and in PVDC packaging materials is 230d.The shelf life of the frozen Scomberomorus niphonius without internal organs in the polyethylene packaging material is 230d,in the composite bag packaging material is 230d,and in PVDC packaging materials is 260d.To Scomberomorus niphonius with internal organs,the polyethylene packaging material is the best.To Scomberomorus niphonius without internal organs,the PVDC packaging material is the best.Results may be affected by microbes and enzymes in internal organs,the concrete question needs further study.Therefore,PVDC can significantly prolong the storage time of frozen fish.During different preservative effect on the blank recuperation Alaska Pollock fillets storage period was studied.Natamycin and nisin samples of pH value,TVB-N,microbial and histamine were superior to not add preservatives samples.Natamycin samples of pH value,microbial and histamine were superior to nisin samples.Nisin samples of TVB-N were superior to natamycin samples.Natamycin and nisin can longer storage period and natamycin is more apparent.Under the condition of 0～4℃,the shelf life of not add preservatives recuperation Alaska Pollock fillets is 16 days,the shelf life of nisin sample is about 18 days,and the shelf life of natamycin sample is about 18 days.Two natural preservative samples can extend the shelf life of blank recuperation Alaska Pollock fillets for 2 days.On the same condition,the effect of natamycin was better than that of nisin.During different preservative effect on the blank recuperation Scomberomorus niphonius fillets storage period was studied.Natamycin and nisin samples of pH value,TVB-N,microbial and histamine were superior to not add preservatives samples.Natamycin samples of pH value were superior to nisin samples.Nisin samples of microbial and histamine were superior to Natamycin samples.Natamycin and nisin can longer storage period and natamycin is more apparent.The same effect between Natamycin and nisin is TVB-N and sensory.Under the condition of 0-4℃,the shelf life of not add preservatives the recuperation Scomberomorus niphonius fillets is 10 days,the shelf life of nisin is about 17 days,and the shelf life of nisin is about 17 days.Two natural preservative samples can extend the shelf life of blank recuperation Scomberomorus niphonius fillets for 7 days.Therefore,natamycin and nisin can significantly prolong the storage time of the recuperation Scomberomorus niphonius fillets. |
