Effect of Repeated Cooking with Bay Leaf on Volatile Flavor Components of Meat Broth

The influence of repeated cooking(5 times)with bay leaf on volatile flavor compounds in pork loin broth was investigated by sensory evaluation,electronic nose and gas chromatography-mass spectrometry(GC-MS). Sensory results elucidated a significant difference on aroma among samples with cooking 1,2,3 times. There were similar odor profiles distinguished by electronic nose among samples with repeated cooking 2,3,4 times,while there were no significant difference with cooking 3,4,5 times. A total of 45 volatile compounds were identified in meat broth cooked with bay leaf with detected by GC-MS. Compared with the control group,the main compounds of eucalyptol,(-)-4-terpineol,α-terpineol,(-)-spathulenol,cedarol,eugenol,4,6-di-tert-butyl-m-cresol,α-terpineyl acetate and so on generated. Samples cooked once had the most composition and contents of volatile compounds and then reduced with recooked times increasing. The contents of alcohol,ether,phenol,and ester compounds decreased sharply after cooking twice. Increasing of volatile flavor components in broth was mostly due to the addition of bay leaf,the overall odor profiles and the types and contents of volatile compounds varied greatly after cooking twice,where the supplementation amount of bay leaf was about 63% of the initial amount at the second time and about 72% of the initial amount at the third time.