Study On The Change Rules Of 13-HODE And 9-HODE During Sausage Processing

13-Hydroxyoctadecadienoic acid(13-HODE)and 9-Hydroxyoctadecadienoic acid(9-HODE),two isomers of Hydroxyoctadecadienoic acid(HODEs),are secondary oxidation products of Linoleic acid(LA),which are widely found in cured meat products,particularly in some cured meat products with higher level.A large number of studies have showed that endogenous HODEs have pathophysiological effects,and elevated HODEs will promote the development or progression of atherosclerosis and certain cancers.In recent years,exogenous HODEs have also been found to have similar pathophysiological effects.Therefore,it is important to analyze 13-HODE and 9-HODE in cured meat products and to investigate the change of HODEs during processing,which could be benefit for controlling the quality of cured meat products in market,as well as providing a theoretical basis for developing new methods to process cured meat products with less HODEs.13-HODE and 9-HODE were selected as study objects in this study and the HPLC-DAD method for simultaneous determination of 13-HODE and 9-HODE in cured meat products was developed.What's more,two kinds of sausages(high-temperature hot-wind drying sausages and low-temperature air-drying sausages),selected as representatives of cured meat products,were produced,the changes of 13-HODE and 9-HODE were analyzed.Finally,by building emulsion system and liposome system,the effects of different physical and chemical factors on the production of 13-HODE and 9-HODE were studied respectively.This paper includes three parts,and the research contents and results are as follows:1)13-HODE and 9-HODE in cured meat products were detected by means of high performance liquid chromatography connected to a diode array detector(HPLC-DAD).The analytes,extracted with methanol and cleaned up by solid phase cleanup with C18 column,were separated on a Lichrosorb Si 60 column(250 × 4.0 mm,5?m)with a mobile phase consisting of n-hexane/isopropanol/acetic acid(98:2:0.5,v/v/v)in isocratic elution and the detection wavelength was set at 234 nm.The results showed that 13-HODE and 9-HODE were displayed good linearity in the ranges of 0.5-20.0 ?g/mL(R2=0.9994)and 1-12.5 ?g/mL(R2=0.9990),respectively.Limits of detection for 13-HODE and 9-HODE were 0.075 and 0.15 ?g/g,and quantification limits were 0.25 and 0.5?g/g,respectively.The average recoveries spiked at different levels were 88.2%and 86.0%,respectively.The method was successfully applied to detect the analytes in 14 cured meat products and the results showed that 13-HODE and 9-HODE were detected on all samples,ranging from 1.2167.54?g/g and 0.63-139.20 ?g/g,respectively.This method was proved to be of high maneuverability as well as excellent sensitivity and accuracy,and could be used for quantitative analysis of 13-HODE and 9-HODE in cured meat samples simultaneously.2)The high-temperature hot-wind drying sausages and low-temperature air-drying sausages were respectively produced,and seven different processing points were set for sampling.The contents of 13-HODE and 9-HODE,salt content,lipoxygenase(LOX)activity and other indexes were monitored during processing.The results showed that similar trends were observed in all indexes:The production of 13-HODE and 9-HODE gradually increased;moisture content gradually decreased;salt content gradually increased;pH showed a fluctuating trend;LOX activity increased after curing,and then gradually decreased;POV and TBARs gradually increased.By the correlation analysis of the indicators,salt may play the inhibition effect on the production of 13-HODE and 9-HODE;by comparing the content of 13-HODE and 9-HODE in the two kind of sausages products,a preliminary conclusion could be obtained:Temperature would promote the production of 13-HODE and 9-HODE;in addition,the variation of 13-HODE and 9-HODE during processing may be concerned with the oxidation ways of LA.3)LA emulsion system and DPPC/LA liposome system were constructed to study the effects of different physical and chemical factors(pH,salt content,and temperature)on the production of 13-HODE and 9-HODE through the LA automatic oxidation or enzymatic oxidation.The results showed that the factors above played some effects on the production of 13-HODE and 9-HODE.The ratio of 13-HODE and 9-HODE was constant under the specific pH value;and the content of 13-HODE and 9-HODE produced by enzymatic oxidation increased with pH value increasing,while their content produced by automatic oxidation decreased.Salt of some range of concentrations could promote the production of 13-HODE and 9-HODE,while the inhibition effect of salt was observed beyond the range of concentrations.Higher temperature would promote the production of 13-HODE and 9-HODE.The results of this experiment would contribute to explain the changes of HODEs during the processing of two kinds of sausages in the experiment above,and providing a foundation for further study of HODEs formation mechanism in the production and processing of cured meat products.