Study On Volatile Compounds And Quality Characteristics Of Small Yellow Croaker During Storage And Air Frying Technology

Pseudosciaena crocea is one of the main economic seafood in China.It has high protein,mineral and vitamin content,low fat content and rich trace element selenium,which has high edible value.In addition,the small yellow croaker itself has a unique flavor and is also popular with consumers.However,the small yellow croaker is not easy to store,which is one of the important factors restricting the development of small yellow croaker,and it will affect the quality and flavor of the small yellow croaker during storage.Secondly,the processing method of small yellow croaker is too single.The traditional processing method is not only easy to destroy the nutrient composition of small yellow croaker,but also harmful to the health of consumers.In this paper,the composition of volatile flavors in different parts of small yellow croaker was identified by headspace solid phase microextraction-gas chromatography-mass spectrometry.The quality indexes and volatilization of small yellow croaker under cold storage(0-4 °C)and frozen storage(-20 °C)were investigated.Changes in sexual flavor substances,analysis of the changes,and the use of air frying technology to process small yellow croaker,the quality of small yellow croaker before and after air frying,determine the appropriate seasoning immersion time and frying temperature and time,thus the small yellow croaker storage management and product processing provide a theoretical basis.The main research contents and results are as follows:(1)The volatile matter substances of fish head,fish skin and fish meat of small yellow croaker were determined by SPME-GC/MS.The volatile flavor substances of fish head,fish skin and fish meat of small yellow croaker were examined separately.There were 67 species,37 species,and 24 species.The total number of volatile flavors detected in each site was the highest,reaching 35 species,followed by hydrocarbons,alcohols,and ketones,respectively 31,29,and 17 Kind.The number of detected esters is small,only 10 species.The results showed that the content of volatile flavors in the head of the small yellow croaker was the highest,followed by the fish skin,and the volatile flavor content in the fish was the least.There are large differences in the types and relative contents of volatile flavors in different parts.The volatile substances in each part are mainly aldehydes,alcohols and hydrocarbons.The ketone content in the head of small yellow croaker is higher than that of fish.In the skin and fish,the ester content in the skin of small yellow croaker is obviously more than fish head and fish.Each part has volatile flavor substances that coexist with each other,and somesubstances are detected separately only in a single part.(2)Determination of sensory evaluation,pH value,TVB-N value,total sulfhydryl content and TBA value of small yellow croaker during storage by storing fresh small yellow croaker under refrigeration and frozen conditions,every 5 days Conduct experimental measurements to explore changes of quality.The results showed that the sensory evaluation score showed a downward trend with the prolongation of storage time.Under the cold storage condition,the sensory evaluation of the yellow croaker was basically lost on the 10 th day and had obvious odor.Under the frozen condition,the color pattern of the small yellow croaker was basically intact within 35 days.The sensory evaluation scores of the lower yellow croaker were higher than those of the refrigerated condition;the pH value of the small yellow croaker decreased first under refrigeration conditions,and then the spoilage deteriorated severely.On the 15 th day,the pH showed an upward trend.The pH value of the frozen yellow croaker showed a downward trend.The content of volatile base nitrogen increased with the increase of storage time.Under the condition of cold storage,the volatile base nitrogen content of small yellow croaker exceeded the national safety limit standard on the 10 th day,and then continued to increase,and the experimental process The odor of ammonia nitrogen can be smelled in the middle;the growth rate of volatile base nitrogen content of small yellow croaker under frozen storage conditions is lower than that of refrigerated conditions,and the volatile base nitrogen content within35 days does not exceed the safety limit standard;total sulfhydryl content during storage decreased,cold storage conditions The total sulfhydryl content of the small yellow croaker decreased rapidly.The total sulfhydryl content of the small yellow croaker under the frozen storage condition was obviously slow.The low temperature could freeze the protein molecules in the fish and play an effective role in protecting the thiobarbituric acid value with the storage time.The extension is showing an upward trend.Under the condition of cold storage,the growth rate is slow in the early stage.Under the frozen condition,the thiobarbituric acid value of the small yellow croaker increases with the freezing time,and the growth rate increases,and the fat oxidation is more serious.(3)The volatile flavor substances of small yellow croaker were measured by SPME-GC/MS to investigate the change trend of volatile substances with time.The trend of volatile matter during storage was investigated.The principal component analysis of fish volatiles was carried out by SPSS software.Correlation analysis of quality indicator changes.The results showed that the volatile matter in different parts of small yellow croaker changed significantly,and the content of volatile substancesincreased.With the prolongation of storage time,the volatile matter of fish head,fish skin and fish of small yellow croaker tended to be consistent.Among them,aldehydes and ketones are gradually increased,alcohols are reduced,and a large amount of amines are produced in the later stage of storage.The main component of the small yellow croaker fish is mainly composed of a small amount of ketones and unsaturated alcohols.The main component 2 is mainly composed of some long-chain aldehydes,all of which are related to volatile base nitrogen and thio.The barbituric acid value showed a positive correlation and a high correlation,which proved that the volatile substances were closely related to the spoilage and fat oxidation of the small yellow croaker.The total sulfhydryl content and pH value showed a certain negative correlation with volatile substances.The comprehensive analysis of the variation of volatile matter in small yellow croaker was closely related to the quality of small yellow croaker.(4)Study the process conditions of air frying of small yellow croaker,use different frying temperature and time and seasoning immersion time as variables,and analyze the changes of nutrient composition and sensory quality of small yellow croaker after processing by complete randomalized design combined with response surface methodology.Find out the best process conditions.The results showed that the frying conditions were as follows: the frying temperature was 176.77 °C when the air-frying small yellow croaker was obtained under different frying temperatures and times and seasoning immersion time based on the single factor test.The frying time was 15.93 min and the seasoning immersion time was 97.52 min.The best frying conditions for retaining higher nutrients are:frying temperature is 176.77 ° C,frying time is 15.93 min,seasoning immersion time is 97.52 min,under which the protein content of small yellow croaker is 20.37 g/100 g,fat content is 1.62 g / 100 g,moisture content is 73.25 g / 100 g.Comprehensive analysis,the final determination of the best process conditions for air fryer frying small yellow croaker is: frying temperature 180 ° C,frying time16 min,seasoning immersion time 95 min.