Study On The Key Volatile Odors And Deodorization Technology Of American Bigmouth Bass

The American bigmouth bass is a large-scale freshwater economic fish produced in North America.It has a high protein content and tender meat.At present,the fish has been farmed in many countries,but the common problem of fish in the American bigmouth bass is still the problem of fishy smell.In this experiment,Mono Trap capture was used in combination with gas chromatography-mass spectrometry-olfactory combined with AEDA method to analyze and study the volatile substances in American bigmouth bass meat.The flesh of the American bigmouth bass was deodorized.The response surface software was used to optimize the design of the degreasing process of the American bigmouth bass The optimal conditions for deodorizing the American bigmouth bass were obtained.The basic nutritional components,minerals,amino acids,and fatty acids of the American bigmouth bass before and after deodorization were compared.The purpose of this study is to obtain the key odor active substances of the American bigmouth bass and reduce its fishy odor,and to explore the best conditions for deodorization of the citric acid-calcium chloride and black tea deodorization method,which provides the future deep processing of the American bigmouth bass.In order to explore the main flavor active substances of American bigmouth bass and improve its fishy taste,two methods of citric acid-calcium chloride and black tea deodorization were used to deodorize American bigmouth bass.The response surface software was used to optimize the design of the American bigmouth bass deodorization process.Volatile substances in American bigmouth bass meat were extracted by MMSE and analyzed by gas chromatography-mass spectrometry-olfactory measurement(GC-MS-O).The optimal conditions for deodorization of calcium are: citric acid concentration of 1.8%,calcium chloride concentration of 0.2%,and deodorization time of 104 minutes.The optimal process conditions for deodorization of black tea are: the amount of black tea is 1.5%,and the soaking time is 41 minutes.The immersion temperature is 43?,and the deodorizing effect is obvious.Under the optimal deodorization conditions,the volatile compounds before and after deodorization of the American bigmouth bass were compared,and it was found that the odorous substances were significantly reduced.Among them,alcohols and aldehydes were the main odorous substances.By comparing the changes of volatile flavor substances in American bigmouth bass,it was determined that the fishy substances might be hexanal,1-penten-3-ol,1-octen-3-ol,E-2-pentenal,and octanal,6-methyl-5-hepten-2-one,etc.Volatile substances in the meat of American bigmouth bass were extracted by MMSE and analyzed by GC-MS-O.42 kinds of volatile components were detected in non-deodorized American bigmouth bass,of which 10 kinds of aldehydes,6 kinds of alcohols,4 kinds of ketones,2 kinds of esters,9 kinds of hydrocarbons,8 kinds of aromatic compounds.Alcohols and carbonyls accounted for 62.78% of volatile compounds,and aromatic compounds accounted for 28.13%.The higher content of volatile substances in carmine fish were benzene(14.87%),hexanal(14.17%),and 1-pentene-3-alcohol(9.88%),toluene(6.32%),1-octen-3-ol(5.44%),1-pentanol(4.61%),benzaldehyde(4.59%),E-2-pentenal(3.39%),2,3-pentanedione(3.39%),octanal(2.92%),nonanal(2.57%),6-methyl-5-hepten-2-one(2.48%),1-Hexanol(1.72%),2,3-octanedione(1.33%),Z-2-penten-1-ol(1.01%),acetophenone(0.75%)and other compounds.Aromatic extract dilution analysis(AEDA)was used to screen the key odor substances to obtain 18 flavor active substances.Among them,the strongest flavor active substances were hexanal(grass odor),1-pentene-3-ol(mushroom odor),and 1-octen-3-ol(mushroom odor)and other substances.The basic nutritional components,amino acids and fatty acids in the back muscles of American bigmouth bass before and after deodorization are compared.The experimental results show that the American bigmouth bass before deodorization is rich in protein and amino acids,and the mineral content is relatively balanced.Crude protein in the back muscles of American bigmouth bass decreased by 39.45% compared with before deodorization.Cu,Fe,and Zn in American bigmouth bass after deodorization decreased by 34.62%,14.45%,and 23.43%,respectively.The content of calcium was reduced by 27.88%,the content of magnesium was reduced by 20.05%,the content of potassium was reduced by 28.67%,and the content of sodium in the American bigmouth bass after deodorization was reduced by 33.77% compared with that before deodorization.Before and after deodorization,the American bigmouth bass meat is rich in essential amino acids.The umami amino acid content before and after deodorization was 8.82g/100 g and 5.28g/100 g,respectively,reaching 38.58% and 37.10% of the total amino acids,respectively.The umami amino acid is an important reason for the delicious taste of aquatic products,which determines its delicious meat.Before being deodorized,the American bigmouth bass was rich in polyunsaturated fatty acids,of which EPA and DHA were high,which could prevent cardiovascular diseases.