Ginger, aroma substance

The fresh ginger root has a citrus and camphorlike, flowery, musty, fatty and green odor. In a column chromatographic preliminary separation of an extract, the characteristic aroma substances appeared in the fraction of the oxidized hydrocarbons. The highest FD factors in dilution analyses were obtained for geraniol, linalool, geranial, cit-ronellyl acetate, bomeol, 1,8-cineol and neral. 

The resinoids described above should be distinguished from prepared oleoresins (e.g., pepper, ginger, and vanilla oleoresins), which are concentrates prepared from spices by solvent extraction. The solvent that is used depends on the spice currently, these products are often obtained by extraction with supercritical carbon dioxide [223a]. Pepper and ginger oleoresins contain not only volatile aroma compounds, but also substances responsible for pungency. 

That many chemical substances are not soluble in sc carbon dioxide permits selective extraction.100 It is often used with foods, for which it eliminates the possibility of leaving toxic residues of solvents such as methylene chloride. It also avoids the hydrolysis that might occur when esters (for flavors or fragrances) are recovered by steam distillation. It has been used to extract the flavor from hops, the caffeine from coffee, fat and cholesterol from foods,101 pecan oil,102 lavender oil (for which hydrolysis of linalyl acetate could occur in steam distillation), 103 ginseng (from which it does not extract pesticide residues),104 ginger,105 microalgae,106 cooked chicken,107 ethanol from cider,108 and many others. One method used with aromas and con-... 

Total extraction has the target to obtain the highest possible yield of soluble substances, whereas a single separation results in a so-called total extract, hut multiple separations allow fractioned products. Typical examples are the extraction of spices, herbs, and hops. One likes to obtain the exhaustive lead substances as a-acids from hops or piperine from pepper, or gingeroles from ginger, or carotinoids from paprika and so on on the one hand and the corresponding aromas on the other. The extraction residue from the extractor is mostly without any value, hut can sometimes be used as fertilizer basis or animal food addition. 

---