Aqueous Two-phase Extraction Of Natural Products And Its Application In Tobacco

Liquid-liquid extraction in aqueous two-phase systems (ATPS), integratesextraction, concentration, purification processes to a single step. The ATPS based onhydrophilic organic solvents and inorganic salts is one of the promising separationtechniques that offers several advantages, including high-polarity, lower cost, the easeof ethanol recovery and simple scale-up. In this paper, ethanol/dipotassium hydrogenphosphate ATPS was performed for the extraction of natural products, and thenapplied successfully to develop natural tobacco flavor.Firstly, in order to test the feasibility of extract by aqueous two-phase extraction(ATPE) using as tobacco flavor and then selecting the most potential naturalproducts for developing tobacco flavor, the extraction of licorice, ficus carica, apple,cocoa, coffee and fenugreek in a30%(w/w) ethanol/40%(w/w) dipotassiumhydrogen phosphate ATPS have been performed. The results indicated that ATPEoffered a new way for developing tobacco flavor. Compared with other naturalproducts, licorice extracts and ficus carica extracts by ATPE have more potential astobacco flavor. Thus, licorice extracts and ficus carica extracts were defined astargets of developing tobacco flavor.Secondly, the operation parameters of ATPE on licorice extracts have beenoptimized and the extracts by ATPE was applied to tobacco flavor. The recovery oftotal flavonoids and glycyrrhizic acid reached up to92.44%and94.86%, respectively,when the system was composed of26%(w/w) ethanol,30%(w/w) dipotassiumhydrogen phosphate,4%(w/w) licorice extracts and room temperature. Comparedwith the traditional extraction of ethyl acetate, the ethanol-rich phase of ATPS attained2.6-fold and6.5-fold the amount of total flavonoids and glycyrrhizic acid,respectively. Moreover, the extracts by ATPE was applied to tobacco flavor, the sensory evaluation indicated that the salt-rich phase made the cigarette smokesmoother and mellower, improved the cigarette quality; the ethanol-rich phase maskthe offensive taste effectively, improved taste of cigarette as flavor.Furthermore, the operation parameters of ATPE on ficus carica extracts havebeen optimized and the extracts by ATPE was applied to tobacco flavor. The resultssuggested that the recovery of total phenolic and total sugar in ethanol-phase was49.50%and7.65%, respectively, after extracting by optimal condition of16%(w/w)ethanol,25%(w/w) dipotassium hydrogen phosphate,3%(w/w) ficus carica extracts,room temperature and no additional sodium chloride. Simultaneously, the ethanol-richphase of ATPS attained about equal yields of total sugar and5-times higher yields oftotal phenolic after the three successive extractions than these achieved by thetraditional extraction of butanol.Finally, the recycling of phase components has been researched. The recovery ofdipotassium hydrogen phosphate reached up to98.4%, when the recycle conditionwas composed of the pH being adjusted to4.0with phosphoric acid firstly, and thenadding2.6-fold the amount of ethanol.