Extraction Of Agarwood Oil And Its Application In Aromatic Paper

Agarwood and agarwood oil have created extremely high commercial value,artistic value and medicinal value due to their unique aromatic smell and pharmacological effects.But at present,the utilization rate of agarwood is low.There was a low extracting rate of agarwood oil,and it usually contained many impurities with an impure aroma.Besides,the structure of products was single and the field of application was narrow,hindering their development in the mass market.Therefore,it is significant to enhance the extracting rate of agarwood oil with low cost,and thus to develop the agarwood products with new features and high added value.In this study,agarwood oil was extracted from agarwood with low resin content and microencapsulated to extend the release of aroma.The microcapsule of agarwood oil was then combined with papermaking technology to produce a new type of aromatic paper having both medical and aromatic effectiveness,so as to promote the development of the agarwood industry and the paper industry.First,the effect of single enzyme,enzyme combination and microwave-assisted enzyme combination process on the extraction of agarwood oil were compared.The aroma,composition and structure of agarwood oil were analyzed.Results showed that in the single enzyme extraction process,when the dosage of cellulase enzyme was 600 U·g^-1,the treatment time was4 h,and the solid-liquid ratio was 1:16 g·m L^-1,the optimal extraction rate of agarwood oil was6.48%.When the dosage of pectinase enzyme was 600 U·g^-1,the treatment time was 3 h,and the solid-liquid ratio was 1:16 g·m L^-1,the optimal extraction rate of agarwood oil was 27.25%.When the dosage of alkaline protease enzyme was 1000 U·g^-1,the treatment time was 3 h,and the solid-liquid ratio was 1:24 g·m L^-1,the optimal extraction rate of agarwood oil was 7.76%.Combining the optimal process of single enzyme,the extraction rate of agarwood oil could be increased to 32.12%.The extraction rate could be further increased to 38.08%with the aid of microwave when the microwave power was 700 W and the treatment time was 5 min.The extracted agarwood oil contained 18 kinds of aromatic compounds,19 kinds of terpene compounds and 6 kinds of chromone compounds,possessing the characteristic smell of agarwood.The content of characteristic substances of agarwood reached 75.31%,and the total amount of detected substances reached 81.63%.Secondly,agarwood oil was encapsulated in microcapsules using urea-formaldehyde prepolymer by the in-situ polymerization method.The content and composition of the core material were determined,and the slow-release performance of the microcapsules was studied.Results showed that agarwood oil microcapsules were successfully prepared when the emulsion was continuously stirred for 3 h at the speed of 600 rpm,the p H of 2.0,and the temperature of34°C.The microcapsules had uniform particle size,good dispersion,moderate shell thickness,and the content of effective core material could reach 80.46%.Moreover,the microencapsulation had almost no influence on the characteristic composition of agarwood.In addition,the agarwood oil microcapsules showed good thermal stability and sustained-release behivior,that only 42.76%of enpsulated agarwood oil was released when placed at 100°C for80 min,whereas the pure agarwood oil was released 64.66%.Finally,the aromatic paper containing agarwood oil microcapsules was prepared by filling in the pulp or spraying on the surface using agarwood dregs and bleached softwood pulp as the raw materials.The effect of microcapsules on the sustained-release effect and mechanical properties of paper were explored.Results showed that the aromatic paper prepared by adding the microcapsule in pulp had better paper structure and aroma slow-release effect compared with spraying on the surface.After being left for 60 days,the fragrance intensity of the aromatic paper was still good.After being left for 75 days,the content of characteristic substances of agarwood in the paper was still as high as 81.80%,and the microcapsules did not peel off.In addition,when the added amount of microcapsules was 2-6%,the aromatic paper had a good mechanical propertiey.