Research from the University of Illinois in the US has found that honey's antioxidant qualities can help preserve meat without compromising taste, at the same time as slowing the oxidation of low-density lipoproteins (LDL), a process that leads to atherosclerotic plaque deposition.
"It still is too early to say definitively, but honey seems to have the potential to serve as a dietary antioxidant," said principal researcher Nicki Engeseth, a professor of food chemistry in the UI College of Agricultural, Consumer and Environmental Sciences.
The latest study, published in the recent edition of the Journal of Agricultural & Food Chemistry, claims to be the first to look at honey's effect on human blood. The study also found, using a much more precise method than one used in an earlier study in 1999, that honey's antioxidants are equal to those in many fruits and vegetables in their ability to counter the degenerating activity of highly reactive molecules known as free radicals.
In January, Engeseth and Jason McKibben, a researcher with Anheuser Busch, reported in the same journal that honey was more effective than traditional preservatives (butylated hydroxytoluene and tocopherol) in slowing oxidation in cooked, refrigerated ground turkey.While the meat browned during cooking more extensively than traditionally preserved products, taste was not negatively affected.
In the latest study, Engeseth and Nele Gheldof, a doctoral student in the department of food science and human nutrition, measured the antioxidant and phenolic contents in honeys taken from seven floral sources.
The study covered acacia, buckwheat, clover, fireweed, Hawaiian Christmas berry, soybean and tupelo honeys. Researchers used the oxygen radical absorbance capacity (ORAC) assay, a tool that for the past decade has been widely used to analyse the same components in fruits, vegetables and wines. Darker honeys had the highest values.
"We got ORAC values ranging from three to 17," Engeseth said. "Commonly consumed fruits and vegetables generally range from 0.5 to 16, based on a per gram basis. This finding is significant, because it clearly shows that there are antioxidants in the honey. If you ate as much honey as you did of melon, for example, you would be getting a similar dose of antioxidants in your diet."
The idea that honey packs healthy quantities of antioxidants strengthens the idea of using honey as sugar substitute, Engeseth said.
The researchers obtained blood samples from healthy human volunteers coming off a 12-hour fast. To the blood, they added the various honey varieties in an experiment to watch honey's impact on LDL, the so-called bad cholesterol. In test samples, they also added copper to stimulate lipoprotein oxidation. Using a spectrometer, they found that honey - the darker the better - dramatically slowed the rate of formation of conjugated dienes, products of oxidation related to LDL in blood.
"The one thing about this study is that even though it involved human blood in a test-tube assay, it does show that if honey is present it can act positively," Engeseth said.
Both recent studies were partially funded by the National Honey Board.