The Effect Of Star Anise On The Volatile Flavor Of Braised Chicken And Its Mechanism

Flavor as an important indicator is usually used to evaluate the quality and commercial value of the traditional pot-stewed meat product.Star anise(lllicium verum)is one of the most common spices in the processing of traditional pot-stewed meat product,and it not only has unique strong aroma but also plays the role to remove objectionable odor as well as preservative effect.It is very important to the formation of flavor of pot-stewed meat product as far as the efficacy is concerned.However,the specific effect and its mechanism of star anise including other spices are not clear and it is difficult to provide theoretical guidance for production,so modernization process and the development of pot-stewed meat product are restricted by some negative factors such as lack of basic and enough theory researches.As the result,it is very important for us to study the effect and its mechanism of star anise to the flavor on stewed chicken.The results will have theoretical significance and practical value to flavor control and promotion standardization of pot-stewed meat product.This paper studied the effect of star anise on the flavor and its precursor substance of pot-stewed chicken meat,and discussed the mechanism of volatile flavor formation on star anise for pot-stewed chicken meat.The main research results were as follows:1.Analysis results of electronic nose showed that star anise made a difference on the total volatile flavor of stewed chicken.2.After adding star anise,species of volatile flavor compounds in stewed chicken had not changed but the specific content and proportion of volatile flavor compounds had changed and at the same time,some added volatile substances were introduced by star anise such as anethole,anisaldehyde and estragole.Cooked before 90 min with low fire,peak area of volatile substances in the control group was significantly higher than the star anise group(p<0.05),and there was no significant difference later;Cooked with high fire 5 min,the total peak area of volatile substances in the control group was significantly higher than star anise group(p<0.05),and total peak area of volatile substances in the star anise group was significantly higher than the control group when cooked 15 min and 30 min.Longer duration of cooking time led to the gradual increase of the quantity and contents of volatile substances introduced by star anise.Main volatile flavor substances were aldehydes and alcohols existing together in stewed chicken after the adding of star anise and anethole as the component of main volatile flavor substances increased in the star anise group.3.There were great changes on the flavor of chicken broth by the adding of star anise,and principal part in flavor in chicken broth was mainly introduced by star anise and the quantity and contents of volatile substance in chicken broth itself were greatly reduced.4.Star anise had no significant effect on pH of stewed chicken and chicken broth(p>0.05),and also had no significant effect on reducing sugar content of stewed chicken(p>0.05),but there were some differences on reducing sugar content in chicken broth,e.g.reducing sugar content was higher in the star anise group than the control group before cooked with low fire for 60 min(p<0.05)and reducing sugar content was below the control group under the conditions of either when cooked with low fire for 60 min or cooked with high fire(p<0.05).5.Star anise had effect on free amino acid content of stewed chicken and chicken broth;various free amino acid and total amino acid were higher in the star anise group than the control group before cooked with low fire for 120 min;but there was a decrease on above-mentioned parameters in the star anise group than the control group(p<0.05)when cooked for 150 min or cooked with high fire;and after adding star anise,the contents of various free amino acid experience droped in some degree.6.Free fatty acid content changed significantly after adding star anise,and especially the effect showed obvious increase in free fatty acid content in stewed chicken when cooked for short time.Free fatty acid content increased before cooked for 90 min with low fire and adding star anise;the content in the star anise group was significantly higher than the control group before cooked for 60 min(p<0.05).The relative contents of polyunsaturated fatty acids in chicken broth increased after adding star anise.The generation of volatile flavor of stewed chicken might be affected by the mechanism through which the star anise exert influence on free fatty acid and then on volatile flavor.7.The effect of thermal degradation products of linoleic acid by star anise was connected with the duration of heating.When heating with shorter time,star anise showed inhibitory effect on oxidation degradation of linoleic acid;however,as the heating time extends,star anise showed facilitating effect on oxidation degradation of linoleic acid.8.Anisaldehydehave,anethole,anise oil as well as star anise all had a significant effect on oxidation and degradation of chicken fat.After adding the above four kinds of materials,the PV and TBA value of chicken fat were lower than in the control group in the early stage of heating(p<0.05)and the contents of chicken fat oxidation degradation products were also below the control group;With heating time extended,the PV,TBA value and the contents of chicken fat oxidation degradation products were higher than in the control group(p<0.05).As a result,the four kinds of materials played inhibitory role on chicken fat oxidation degradation when with short heating-up period but played a driving role with long heating-up period.9.The way of the role of star anise for stewed chicken flavor lied in inhibition of free fatty acid oxidation degradation in the early stage of cooking period;but in the later stage of cooking period,the way mainly lied in release of innate volatile substances in star anise and transfer into chicken other than the role of star anise acting on the free fatty acid.