Research Of Identification And Extraction Of Vanilla Volatile Components

Vanilla as a kind of valuable natural spice enjoys the reputation of the king of all perfumes. It has been widely used in foodstuffs and cosmetics industry. China started the research of vanilla in60s of last century and now vanilla has been one of the characteristic industries of Hainan. However, the odor components of Hainan vanilla has been unknown so far and the extraction method has faced the problems of low yield and time-consuming. Therefore, volatile components of vanilla in Hainan have been invested in this research. Also, the effects of several extraction methods on the vanilla were compared. By analyzing the vanilla extraction processing and constructing a kinetics model, the vanillin yield can be predicted in different extracted conditions. Lastly, the qualities of vanilla from different origin and at different grades were analyzed and compared, include volatile components and antioxidant activity. The main results are as follows:The condition of solid phase micro-extraction (SPME) for extraction of volatile components in vanilla of Hainan was optimized and the volatile components in vanilla were extracted by simultaneous distillation and extraction (SDE) and SPME. The results showed the optimal condition was as follows:extraction head of75μm CAR/PDMS, extraction temperature80℃and extraction time20min.105volatile components were identified. In these components,73volatile compounds were extracted by SDE and78by SPME.Vanillin yield, extraction time, antioxidant activity and overall odor of vanilla extracts obtained by UAE, MAE, PAE and maceration were systematically investigated. As a result, MAE showed the strongest extraction power, shortest extraction times and highest antioxidant activity. Vanillin yield of maceration was higher than UAE and PAE, and the antioxidant activity was similar to UAE, whereas the extraction process was much more time-consuming than UAE and PAE. Overall odors intensity of different vanilla extracts obtained by UAE PAE and MAE were similar, while higher than the maceration extracts. Taken together, MAE is the best choice for the extraction process of cured vanilla.Then, the parameters for MAE treatment such as particle size and sample/solvent ratio were optimized. Results show that vanillin yield increases with decreasing particle size and sample/solvent ratio and that powered vanilla bean with a sample/solvent ratio of4g/100mL are the optimum conditions for vanillin extraction. Next, two-site kinetic equations, which has low root-mean-square deviation and high R2values, was shown to be more suitable in describing the kinetics of vanillin extraction compared with other three model equations. The parameters Ceq, k1, k2, and f were extracted and fitted as functions of irradiation power and ethanol concentration with high R2values (R2adj=0.969-0.996) by using second-order polynomial function. A kinetics model with high accuracy was constructed to describe vanillin extraction in terms of irradiation power, ethanol concentration, and extraction time.Contents of four main odor components in Tonga, Comorin and Hainan vanilla, and antioxidant activity of vanilla extracts were compared. SPME-GC-MS was used to analyze the odor components in the three kinds of vanilla. The results indicate that, compared with the other two vanilla, Tonga vanilla contained the highest4-hydroxy benzaldehyde and4-hydroxybenzoic acid content and owned similar vanillin content to Hainan vanilla, however Comorin vanilla had the highest content of vanillic acid. Tonga vanilla extracts showed the strongest antioxidant activity, followed by Comorin vanilla and Hainan vanilla showed the lowest activity.67,69and73components were indentified in Tonga Comorin and Hainan vanilla respectively, and in which2,3-butanedione, acetic acid,2-butanone3-hydroxy,23-butanediol (isol),23-butanediol (iso2), furfural, phenol, phenol4-methyl, phenol2-methoxy and vanillin were with high content and changed according the variety of vanilla. Aromatic compounds with the highest contents in these three kinds of vanilla were the most important odor compounds in vanilla.