Study On The Optimization Of Smoked Pangasius Technology And The Effect Of Storage On Quality

Smoked pansa fish products are deeply loved by consumers because of their unique smoky flavor.However,the processing method of smoked food generally only adopts the family workshop.This method not only makes the stability of the product difficult to control,but also produces a large amount of formaldehyde and polycyclic aromatic hydrocarbons,which is easy to cause great harm to the human body.Problems such as benzopyrene(BaP)residues in smoked products have attracted more and more attention from consumers,and have had an impact on the sales market of smoked products.In addition,the smoked products are susceptible to temperature,light,oxygen,and metal ions during processing and storage,which can cause oxidative deterioration of lipids and proteins,destroy their physiological functions,and finally decompose into free fatty acids and have bad effects.Flavored small molecules such as alcohols,ketones,aldehydes and other compounds,have bad effects on its overall quality.The BaP residue in smoked products,easy oxidation and storage problems are the main problems that hinder the rapid development of smoked products.Therefore,studying the effects of smoking process on the physical and chemical indicators,sensory characteristics,BaP content and volatile component composition of pangasius and analyzing its storage stability are useful for optimizing the smoking process,extending the shelf life of the product and improving the quality of smoked pangasius.In this study,the pangasius was used as experimental material,the effects of smoking technology(drying time,smoking time,and smoking temperature)on the sensory indicators and texture characteristics of the pangasius were analyzed.Based on the optimized smoking process,the pre-solid phase adsorption device is used to filter the BaP compounds in the smoke on-line.The effect of four solid phase fillers of cotton,silica gel,molecular sieve,and activated alumina on BaP and aroma in smoked pangasius is compared.Finally,the quality changes of smoked pangasius before and after silica gel pre-solid phase adsorption treatment were studied based on the analysis of the physical and chemical indicators(moisture,p H,total number of colonies,TBARS,color and texture)and volatile flavor components during storage period(0,30,60,90,120 d).The main research results are as follows:1.The effects of smoking technology on the sensory indicators and texture properties of the pangasius were studied.Firstly,the effect of smoking technology on the color,texture and sensory characteristics of the sample was analyzed by the single factor test.On the basis of single factor experiment,the effects and interaction of drying time,smoking time,and smoking temperature on the sensory characteristics of smoked pangasius were analyzed and the regression model of the smoked pangasius technology was determined by response surface analysis.The optimal parameters were determined: drying time 30 min,smoking time30 min,smoking temperature 90?.Under this technological condition,the quality of smoked pangasius has been significantly improved.The color index obtained: L value 38.254,a value16.351,b value 20.046;texture index: hardness 6.752 N,elasticity 7.744 mm,cohesion 5.214 N,chewiness 24.856 m J;sensory score is 35 points.The quality of smoked pangasius can effectively improve by the optimized smoked pangasius technology and provide a certain theoretical reference for the production and processing of smoked meat products.2.To reduce the content of benzopyrene(BaP)in smoked fish fillet and retain its sensory characteristics and flavor quality,the smoke was introduced into a online filtration unit to optimize the processing technology of smoked fish fillets.The effect of different solid sorbents(cotton,silica gel,molecular sieve,activated alumina)on the quality of smoked fish fillets were compared.The BaP in smoked fish fillet detected by high performance liquid chromatography(HPLC),while the volatile flavor compounds were analyzed by gas chromatography/mass spectrometry(GC/MS).The results indicated that after online filtration,the BaP decreased significantly.In comparing different solid-phase sorbents,the BaP content of the smoked fish fillets treated by silica gel was detected to be 4.81 ?g/kg,and high sensory scores in texture,color,and aroma could be obtained,since the friendly volatile substances such as phenols,aldehydes,etc.were well retained.Finally,the process of reducing BaP content in smoked sturgeon fillets was optimized by response surface method,and the optimal conditions were silica 25 g,smoking time 30 min,and temperature 85 ?.The results could provide important reference for the development of healthy smoked food.3.During the entire storage period(0,30,60,90,120 d),the moisture content of the smoked pangasius before and after the silica gel pre-solid phase adsorption treatment continued to decrease along with the increase of storage days,whereas the total number of colonies and TBARS of the two samples increase.The p H of the samples dropped first and then rose,and the p H of the samples without adsorption treatment was higher than that of the samples treated with silica gel,and the color and texture were both deteriorating.The volatile compounds of two samples during storage were analyzed by laser irradiation desorption-headspace solid phase microextraction-gas chromatography mass spectrometry(LID-HS-SPME-GC-MS).The results showed that the contents of characteristic phenolic substances such as guaiacol,2-methoxy-4-propyl-phenol,4-ethylguaiacol,2,6-dimethoxyphenol,etc.in the two groups of samples generally decreased along with the extension of storage days,resulting in a gradual weakening of the smoky flavor and quality deterioration,while the content of aldehydes,alcohols and ketones with undesirable flavors increased.The storage stability of smoked pangasius treated with silica gel pre-solid phase adsorption was better than that of unadsorbed samples.Based on PCA and OPLS-DA analysis,it was proved that nonanal,guaiacol,oxalic acid,2-methoxy-4-propyl-phenol,isoamyl alcohol,4-ethylguaiacol,2,6-di methoxyphenol were important characteristic substances of flavor changes during storage of samples adsorbed with silica gel.This result could provide theoretical support for extending the shelf life of smoked products.