When it comes to aesthetics, food is not an exception. We tend to become apprehensive and judgemental if the object of visual appreciation looks different than others from the same category. If it does not fit in the common expected looks, we tend to panic. Ginger is an example of this reaction. When ginger bought from a store, after cutting or breaking a piece, happens to show a "blue ring" inside and around the peripheral inner area, it is NOT a sign of something wrong with the ginger, it is actually a terapheutical ginger and we should considered ourselves lucky to have found it, and usually it is sold at the same price of the other yellow and white types.
The research indicates the following:
Paul Schulick in his book entitled: Ginger: Common spice & wonder drug, states the following:
"The ginger rhizome is aromatic and thick lobed and ranges from white to yellow in color: One of the prized varieties and most unusual exception to this color range is a variety that possesses a characteristic blue ring which circles the fleshy interior." (p.6)
Additionally, the National Cancer Institute has recently identified ginger as one of the top ten foods offering the highest levels of anti-cancer activity. Most importantly, ginger accomplishes all these without the side effects associated with drugs. As is true of all botanicals, growing conditions and quality have enormous impact on the quantity of active compounds found in ginger. Look for the highest-grade organic ginger you can find. In many cases, a blend of fresh and dried ginger is most effective.
Today not only is it our most widely cultivated spice, it is also one of the most widely researched. Norman Farnsworth, Ph. D., senior university scholar of pharmacology and Director of the World Health Organization Centre for Traditional Medicine at the University of Illinois, calls ginger "one of the three most thoroughly investigated plants in the history of the world." As is the case with many herbs, current research and clinical studies validate the traditional or "folk" uses of the plant.
Moreover, when selecting ginger, please be aware that quality matters. There are many grades of ginger available. For best results, choose the highest grades. It is also wise to select ginger products manufactured from the 'blue ring' variety of ginger. Medical research has found this particular variety contains the highest level of digestive enzymes. Finally, ginger is a heavily fumigated crop. If you are using concentrated forms of ginger (extracts, syrups and dried powder), you are also potentially receiving concentrated amounts of these chemicals. For this reason, it is wise to seek out organic sources and products.