Evaluation Of Youtiao Flavor And Preliminary Studies On Its Formation Mechanismt

Flavor is an important indicator of the quality of food.Youtiao,a traditional fried cereal-based food,is popular for consumers because of its good flavor and taste.At present,the research on Youtiao flavor is not abundant,so it is of practical significance to further understand the mechanism and influencing factors of Youtiao flavor.In this experiment,different vegetable oils and flours were used as raw materials to study their effects on Youtiao flavor through the method of headspace solid-phase microextraction(HS-SPME)/ gas chromatograph-mass spectrometry(GC-MS).The paper mainly focuse on the determination of the main flavor substances and the formation mechanism of flavor,and the influencing factors of flavor as well as the relationship between Youtiao flavor and the quality of finished products are also investigated.The results obtained were as follows:(1)The optimal HS-SPME condition was established by the use of a CAR/PDMS fiber,extraction at 70? for 40 minutes,and desorption for 5 minutes.In addition,the volatile flavor of Youtiao was mainly derived from the crust,and aldehydes may have the greatest effect on the formation of its flavor.(2)A total of 118 major volatile compounds were found during the processing of Youtiao,mainly including aldehydes and heterocycles.(E)-2-nonenal,(E,Z)-2,6-nonadienal,(E)-2-decenal,(E,E)-2,4-nonadienal and(E,E)-2,4-decadienal,were the key flavor compounds(0.1 ?ROAV < 1)3-methylbutanal,nonanal,(E)-2-octenal,(E,E)-2,4-heptadienal,and 1-octen-3-ol also played an important role in the flavor formation of Youtiao.Besides,(E,E)-2,4-decadienal had the greatest contribution to the formation of the whole flavor,and 2-ethyl-3,5-dimethylpyrazine was the major auxiliary flavoring substance.In addition,aldehydes were the main flavor components of Youtiao.(3)The formation of volatile flavor components of Youtiao is mainly the result of oil oxidation reaction and Maillard reaction,and the oxidation of oil played a dominant role.Glucose content from 0.4% to 0.6% can not only enrich the flavor composition of Youtiao but also adjust the products of oil oxidation in a more appropriate level to meet the more consumers demand.(4)Flour and a small amount addition of protein(< 6%)and starch(< 12%)had a little effect on the formation of Youtiao flavor.The excessive addition of protein and starch obtained a great influence on the formation of flavor.Frying oil and frying temperature were the major influence factors,and frying temperature should be controlled at about 190 ~ 210 ?.(5)Flavor was an important indicator of the quality of Youtiao,but to some extent,it was also influenced by the organizational structure,texture and other quality indicators of Youtiao.In addition,Reasonable regulation of Maillard reaction and fat oxidation can make Youtiao with the quality of both a pleasant and delicious taste and a desired organizational structure.