Studies On Major Flavor Compounds In Jackfruit And Jackfruit Juice During Key Processing Units

Frangrance is one of the most important fruits’component and their products. Aroma compounds of frangrance are very complexed, because different compositions or proportions will lead to different overall aroma. Target at the question of most of aroma compounds would volatilize durning the processing and storage due to their volatility and unstability. This would led to products change because of the variability of products frangrance. Studying fruits’aroma compounds and their changes during processing is very important for exploiting fruit resources and their products. Jackfruit will show good prospects in the future because of its unique and attractive frangrance. Aroma compounds of9kinds of jackfruits harvested from Hainan provience in China and their changes during juice processing were investigated by headspace solid phase microextraction (HS-SPME) combined with gas chromatography mass spectrometry analysis (GC-MS) detection technology. In addition, electronic nose and electronic tongue were used to compare flavor changes in the juice process. Dates were processed by using Principal Component Analysis (PCA) and Cluster Analysis (CA). The results showed as follow.1. Optimum conditions of HS-SPME/GC-MS analysis jackfruit aroma compounds were:DVB/PDMS fiber, no Nacl addition, sample weight10g, extraction temperature40℃, equilibration time10min, extraction time90min. Under this condition, main aroma compounds from9main jackfruit cultivars in Hainan province, were composed of propyl isovalerate, amyl isovalerate, butyl isovalerate, isoamyl isovalerate, isobutyl isovalerate,(3-Cyclocitral and hexyl acetate.2. Aroma compounds of the9jackfruit cultivars pulp changed after sterilization as follow. First, the content of aroma compounds changed from62to59in which39kinds compounds disappeared while36kinds appeared, in addition lauraldehyde and valeric acid were not detected. Second, content of the same aroma component changed at different degrees in which some increased while some declined. Third, aroma compounds of different jackfruit varieties showed different thermal stability. In which xlbd2, ml and m3showed the best thermal stability, while m4and m6showed the worst thermal stability.3. Sensory quality of different cultivavars jackfruits showed ml, m3, m5, XYS4, xlbdland xlbd2had attractive tinct, nice flavor and rich characteristic odour. Author thought that ml and xlbd2were best varieties for juice processing based on thermal stability of the aroma compounds and other quality.4. The most significant operation processing on the aroma compound of jackfruit were enzyme and sterilization. The amount of aldehydes and alkene compounds increased while acetic acid,2-ethylhexyl ester and hexanoic acid disappeared after enzyme treatment. Aroma compounds significantly decreased and some heat-sensitive compounds disappeared after sterilization. After enzyme treatment, content of Vc decreased significantly whereas pH, acids, sugar and the total soluble solid contention increased. In addition, the colour of jackfruit juice didn’t significantly changed. Thus enzyme treatment showed the effect of increasing frangrance. The quadratic orthogonal design was employed to optimize the jackfruit juice production. It resulted in the optimal condition in view of the pectinase of0.46%, hemicellulose of0.34%, enzymatic temperature of50℃, time of60mins. Then inactivate the enzyme. After that,0.5%of β-glycosidase was added and cultivated at temperature of40℃for60mins, Then inactivate the enzyme. Furthermore, composite enzyme treatment could show the effect of enhance output rate of juice in the experiments.