Effects Of Different Treatment Conditions On The Degradation Of ATP And Its Related Products In Pacific White Shrimp(penaeus Vannamei)

Fish,shrimp,shellfish and other aquatic products will undergo a series of biochemical reactions after death,leading to the rapid degradation of ATP and affecting the quality of aquatic products.ATP and its related components are closely related to the flavor and freshness of aquatic products.It is particularly important to delay and regulate the degradation of ATP during storage and processing.At present,domestic and foreign scholars mainly focus on fish,marine invertebrates are less studied.Pacific White shrimp is rich in production and has high commercial value,so the research is of great significance.The degradation pathway of ATP is more complex,and the degradation pathway of different species may be different.In this paper,Antarctic krill is used as a comparative study.At present,the regulation of ATP degradation is mostly used as storage methods,and there are few studies on the heating methods.Therefore,the degradation degree of ATP in minced shrimp was observed from the aspects of heating,storage time and addition of metal ions.The degradation of ATP and its related components were regulated by changing species,temperature,ion concentration and treatment methods,and the optimum conditions were determined according to flavor and freshness.The main contents and conclusions are as follows:1.The effects of different heating methods?microwave heating,water bath heating and combined heating?on the degradation of ATP and related products in mince Pacific white shrimp were studied.The results showed that the main changes in minced Pacific white shrimp were adenosine monophosphate?AMP?and inosinic acid?IMP?before and after heating.The contents of adenosine triphosphate?ATP?,adenosine diphosphate?ADP?,inosine?HxR?and hypoxanthine?Hx?were low.The degradation of ATP can be controlled by water bath heating at 85 and 95?and combined heating.Compared with water bath heating,more IMP content,less heating time,and better flavor were obtained by combined heating for Pacific white shrimp.The different methods were compared in terms of IMP content and flavor/bitter ratio,which are related to flavor of aquatic products.The best heating method was pre-heating at 75?in water bath followed by microwave heating at 95??IMP content and relatively flavor/bitter ratio were 4.34?mol/g and 3.00,respectively?.2.The effects of different heating methods?microwave heating,water bath heating and combined heating?on the degradation of ATP and its related components in Antarctic krill meat were studied.Compared with the minced Pacific white shrimp,the changes of 6 nucleotides were smaller before and after microwave heating,water bath heating and combined heating in minced Antarctic krill.The heating time of the combined heating is moderate,which is more favorable to the uniform heating of the sample.Therefore,in terms of fresh-bitter ratio,the best combination heating method of Antarctic krill is pre-heating at 65?in microwave followed by water bath heating at 95??fresh-bitter ratio is 0.06?.Chemical analysis,microbial analysis and sensory evaluation showed that K value was not suitable for evaluating the freshness of minced Antarctic krill,which indicated that the degradation pathways of Pacific white shrimp and Antarctic krill were very different.Thus,the relationship between ATP degradation pathway and species was verified.3.We studied the effects of different metal ions on the degradation of ATP and its related components during one week storage at 4?for Pacific white shrimp,as well as the effects of freshness and flavor of minced shrimp.The results showed that with the increase of storage time,the ATP,ADP and AMP showed a downward trend.Both HxR and Hx increased first and then decreased.Except for 1mM Zn²⁺and 10mM Cu²⁺,the AMP increased first and then decreased,and the AMP in the other treatments showed a downward trend.In addition to the effect of Cu²⁺on the spoilage of minced shrimp meat,the other metal ions could inhibit the spoilage of minced shrimp meat in order of 5,10mM Zn²⁺>1mM Zn²⁺,10mM Al³⁺>1mM Al³⁺>5mM Al³⁺,10mM Fe³⁺>5mM Fe³⁺>1mM Fe³⁺.The minced shrimp treated with metal ion was stored at 4?for 1-2 days?24h-48 h?and then consumed with higher IMP content and better taste.As far as fresh-bitter ratio is concerned,The optimal treatments of the four solutions were as follows:the shrimp minced with 10 mM Zn²⁺or 10 mM Cu²⁺was stored at 4?for 0 h?fresh/bitter ratio was 27.28 and 6.46,respectively?,and the shrimp minced meat with 5 mM Al³⁺solution or 10 mM Fe³⁺solution was stored at 4?for 6 h?fresh/bitter ratio was 14.39 and 7.02,respectively?.Shrimp stir into minced shrimp,the taste of minced shrimp is better in a short time.