Effects Of Staranise Extract On Biogenic Amines Formation And Volatile Flavor Quality Of Dry-cured Perch

Salted aquatic products are well received by consumers because of their unique flavor.However,because the protein in aquatic products is conducive to the growth of microorganisms and the free amino acid produced by hydrolysis of protein provides a precursor for the formation of biogenic amines,meanwhile aquatic products occurs amino acid decarboxylation and deamination of lipid oxidation reaction during the processing,salted aquatic products are prone to cause food safety issues,Such as high cntent of amines and microbial,the content of aldehyde ketones increasing.This thesis explores the effects of star anise extract on biogenic amines formation and volatile flavor quality of dry-cured perch.The main contents are as follows:1.Inhibition of Microorganism and Biogenic Amines Formation in Dry-cured Perch by Star Anise ExtractFresh perch was used as the material,adding different concentration of star anise extract(0,100,300,500 mg/kg)at the salting process.The inhibition of microorganism and biogenic amines during the processing and storage of dry-cured perch were studied by analyzing the changes of microorganism and biogenic amine content in samples.The results showed that the star anise extract could significantly inhibit the total plate count,lactic acid bacteria,Staphylococcus,Enterobacteriaceae,and TVBN compared to the control.Five kinds of biogenic amines were detected during the processing and storage of dry-cured perch,including putrescine,cadaverine,histamine,tyranine and phenethylamine,and star anise extract has significant inhibitory effect on above five kinds of biogenic amines,treatment with 300 mg/kg star anise extract had the lowest content of biogenic amines.Principal component analysis(PCA)indicated that free amino acid was no significantly related with biogenic amines.Star anise extract could reduce the foramation of biogenic amines by inhibiting the total plate count,Enterobacteriaceae and Staphylococcus.2.Effects of star anise extract and partial replacement of NaCl by KCl on the regulation of biogenic amines in dry-cured perchIn order to further improve the safety and edible quality of dry-cured perch,fresh perch was used as the material,and treated with star anise extract combined with partial replacement of NaCl by KCl at the salting process.Star anise extract dose and Salt substitution ratio were optimized using central composite design,and the regulation method of biogenic amines was explored by analyzing the interactive effects of star anise extract and partial replacement of NaCl by KCl on biogenic amines.Results showed star anise extract and replacement ratio of KCl had significant interactive effect on the total amount of biogenic amines.With the added amount of star anise extract,the threshold of KCl replacement ratio affecting the total amount of biogenic amines gradually reduced.By using quadratic regression model,the optimization results were as follows:star anise extract 340.00mg/kg and salt replacement ratio 20.00%.Under these conditions,the total amount of biogenic amines was determined as 113.36 ± 2.66mg/kg and the total number of colonies was 4.79 ± 0.12 lg CFU/g.3.Effects of star anise extract on volatile flavor quality of dry-cured perchThe objective of this study is to discuss the effect of star anise extract on flavor compounds and sensory quality of dry-cured perch by using SPME combined with GC-MS method to identify the volatile flavor compounds.The results indicated that star anise extract could significantly increase the types of aldehydes,alcohols and hydrocarbons flavor ingredients of dry-cured perch,including Cis-anethole,Anisaldehyde,Lauryl alcohol,Linalool,Eudesmol,2-Nonanone,Hydroxyacetone,Estragole,D-limonene and?-phellandrene.Compared with other different control group,star anise extract could significantly reduce the content of hexanal,octyl aldehyde and nonanal,but had no significant effect on the relative content of other flavor substances in dry-cured perch.In addition,star anise extract could significantly increase the juiciness,odor intensity and aftertaste of dry-cured perch.