Study On Change Of Flavour In The Qiao Qi Ham During The Processing Time

Flavour is an important quality index of dry-cured ham as well as an crucial fator which affects consumer's acceptability.The qiaoqi ham came from qiaoqi Zang Baoxing county of Ya'an city in Sichuan province was popular among many people because of its particular flavour.But nobody studied why it was so popular still now.The research was intented to find a better method which was suitable to study the aroma of qiao qi ham and to discuss the chang of flavour during the processing time by studing on the extraction method of aroma and the chang of flavour compounds,savour compounds as well as the chang of physical and chemical indices. Then it could provided a new method to evaluate the flavor of this traditional product.The specific research contents and results were as follows:1. Study on the method that extracted volatile aroma compounds of Qiqoqi hamThe objective of this research was to study the volatile aroma compounds of bices femoris divided from qiaoqi ham that processed after 180d by using simultaneous distillation-extraction (SDE) and solid-phase microextraction(SPME),and then the different time (2h3h,4h) of simultaneous distillation-extraction and different fiber coatings 75umcar-boxen/polydimethylsiloxane(75umCAR/PDMS)and50um/30mmdivinylbenzene/c arboxen/polydimethylsiloxane(50um/30mmDVB/CAR/PDMS) were studied,and gas chromatography-mass spectrometry was used in the analysis. The results showed that the best extraction time is three hours with ether used as solvent and 75um CAR/PDMS coating was suitable for studing qiaoqi ham;SDE detected 44 volatile aroma compounds while SPME detected 66, which using their best operation;the results also showed that SPME was more suitable for detecting and extracting qiaoqi ham by comparing with SDE.2.Study on the optimized method of SPME that extracted volatile aroma compounds of Qiaoqi hamThe objective of this research was to study the extraction effect of SPME with 75um CAR/PDMS under different extracted temperature,extracted time,equilibrium time and the content of Nacl, which was used to study the volatile aroma compounds of bices femoris divided from qiaoqi ham that processed after 180d. The result showed that the best extracted condition for 75um CAR/PDMS was using extacted time in 60min, extracted temperature for 45℃, equilibrium time in 10min and the content of Nacl in unsaturated. And the detected compounds were the most that was 67 under this condition.3.Study on the change of qiaoqi ham's volatile aroma compounds during the processing timeThe research use SPME with 75um CAR/PDMS to study the aroma copounds of bices femoris divided from qiao qi ham that processed after 0d,45d,90d,135d,180d and 225d,and in the analysis, gas chromatography-mass spectrometry was used.The result showed that aldehydes,alcohols,ketones,acids,esters, hydroearbons, phenols and others were the major volatile aroma compounds of qiaoqi ham;and during the whole processing time, the relative content of aldehydes,acids, hydroearbons, esters,and phenols were increased in the whole; the relative content of alcohols and ketones were decreased;the other compounds were diverse,but still increased in the whole.4.Study on the chang of protein and free amino acid in qiaoqi ham during the processing timeThe protein and free amino acid of qiao qi ham which were bices femoris,semitendinosus,semimembranosus that processed after 0d,45d,90d,135d,180d and 225d were studied during the processing time by SDS-PAGE and mensurating free amino acid.The change of myosinogen hydrolysis and the content of free amino acid were studied. The results showed that,during the whole processing time,myosinogen of biceps femoris hydrolyzed obviously,so did semitendinosus and semimembranosus;especially the ham processed after 225 day,which hydrolyzed produts were incresed obviously between 20,000Da and 14,400Da;Free amino acid content were increased during different processing time,and made special flavour of qiaoqi ham.5.Study on the physical and chemical indices of qiaoqi ham during the processing timeThe physical and chemical indices of qiaoqi ham were studied during the processing time,and the material were the bices femoris,Semitendinosus,and Semimembranosus which were processed after 0d,45d,90d,135d,180d and 225d. The result showed that,during the whole processing time,the main physical and chemical indices of qiaoqi ham were changed observably.The content of Nacl were increased while the content of water were decreased;The TBA and acid value were rised along with the processing time increasing;pH were changed a little;The PI indexes and NPN were changed conformably which increased along with the processing time increasing, and the PI indexes increased among a range.