Ginger Oleoresin

#### Ginger Oleoresin. **Ginger Oleoresin **is a prepared oleoresin. It is produced by extraction of the dried and unpeeled rhizome of Zingiber Officinale, ground to a moderately coarse powder. The solvent is ethyl- ether, acetone, ethyl alcohol, occasionally chlorinated hydrocarbons, but rarely benzene which is highly toxic. The removal of the last few percents of solvent is a problem which has yet to be solved satisfactorily. Certain solvents can be removed almost quantitatively through the use of small amounts of ethylalcohol as a "chaser" during the last stages of evaporation. **Ginger**** ****Oleoresin **is extracted from various types of ginger (see **Ginger**** ****Oil**), but the majority of all ginger oleoresins are derived from Nigerian and Jamaican ginger, the former being the most inexpensive material, the latter having the most refined aroma. From the southwest coast of India comes a highly appreciated quality of ginger which is preferred for the production of oleoresin for use in carbonated beverages (**Ginger Ale**, etc.). Ginger oleoresin is a dark brown or very dark amber colored, viscous liquid which usually deposits a grainy mass at the bottom of the container. The contents of a container should be thoroughly stirred before the material is weighed for compounding or sale. The odor of ginger oleoresin is warm-spicy, sweet and very aromatic-rich. The flavor is equally warm, but pungent-biting, leaving a peculiar cooling aftertaste almost as a reaction to the pungency. It gives an immediate feeling of heat and produces perspiration from the facial glands. The reader, who may have tasted Chinese candied ginger or a good ginger-nut (cookie) along with a cup of hot tea, will certainly agree that this combination can produce a breathtaking heat-shock. Ginger oleoresin is used in numerous sorts of baked goods, spice blends, meat sauces, chutneys, candies, throat lozenges and, more recently, in carbonated soft drinks (**Ginger Ale**, etc.). The latter application has become one of the major outlets for ginger oleoresin during the past decade or two. For this purpose, ginger oleoresin is frequently adulterated with capsicum oleoresin (see **Capsicum**), whose pungent effect is many times greater than that of ginger. The pungency of ginger oleoresin preparations disappears after treatment with hot alkali, while the pungency of capsicum is resistant to this test. Capsicum additions to ginger preparations may be detected in this way. Ginger oleoresin can replace the powdered ginger rhizome in Indian curry powder, but it is still customary to prepare this spice blend exclusively from powdered botanical drugs. Capsicum oleoresin does not contain any essential oil, while **Ginger**** ****Oleoresin**** **contains from 15 to 30% of essential oil (ginger oil). Oleoresins from Nigerian ginger may contain as much as 25 to 35% of essential oil, while the oleoresins from Jamaican or south Indian ginger usually have a lower oil content but a considerably higher content of the resinous matter in which we find the pungent principles. The ketone, **Zingerone**, which has been named as "a principal constituent of ginger" has been produced synthetically from vanillin and acetone by condensation followed by hydrogenation. However, the author has been unable to detect any pungency in the flavor of synthetic zingerone at the concentration of 0.50 to 1.00 mg%. This concentration is higher than the concentration of natural zingerone in any finished product on the market. It seems more likely, that this ketone is the decomposition product which is formed when the pungent principle (or principles) in ginger is treated with hot alkali (see the above test for adulteration of ginger oleoresin with capsicum oleoresin). The pungent principles in ginger thus seem to be condensation products of zingerone with aliphatic aldehydes (hexanal and heptanal in particular). These facts should be kept in mind when ginger oleoresin is used in finished goods where alkali is present. Potassium carbonate is used to improve the crunchy texture of certain spice cookies. This type of alkali is liable to ruin the pungency of ginger in the baked goods. Certain types of ginger cookies are flavored with a ginger-lemon combination which enables the manufacturer to use a small amount of citric acid along with the flavor. In the latter case, the pungency of the ginger oleoresin (or ginger powder) is maintained. **Ginger Oleoresin **is rarely used in perfumes, partly because of its poor solubility in alcohol (except when it happens to be an "alcoholextracted oleoresin"), partly because of its color and incompatibility with a number of perfume chemicals. A few manufacturers of perfume raw materials and flavor concentrates have produced various interesting **"Ginger Absolutes" **or specialties like the **Ginger Butaflor. **This product probably represents the highest concentration of the odor and flavor principles in ginger rhizome (see also **Ginger Absolute**). Odorless or tasteless ballast resins and similar extractive matter with no individual odor or flavor have been eliminated in a selective solvent extraction. A highly true-to- nature, viscous, dark amber colored extract is the result. Such materials are useful in perfumery where a richer, warmer gingernote or undertone is wanted. It should be mentioned that these special extracts are five to ten times more expensive than ordinary oleoresins.