Raspberries may beat tummy bugs
November 4
Researchers in Finland have discovered a compound of certain berries which may restrict the growth of ‘bad’ intestinal bacteria. The team from the University of Helsinki found that cloudberries and raspberries contain ellagic tannin, an acidic compound. It inhibits the growth of damaging intestinal bacteria and encourages the growth of beneficial ones. About ten bacteria which cause infections of the alimentary canal and food poisoning were used, including salmonella and listeria. The compound prevented the spreading of salmonella, staphylococcus and camphylobacter, but did not affect listeria. “Understanding the interaction of phenolic compounds and bacteria of the alimentary canal is important, for example for developing functional foods. As antimicrobial compounds, phenols may have a previously unforeseen effect on intestinal microbes,” says Project director, Riitta Puupponen-Pimiä. Cloudberries and raspberries were among several berries studied, but the other berries only contained small quantities of ellagic tannin. The team suggest that the compound could possibly be used in new types of safe food packaging and preservatives, and in medication for upset stomachs. Ms Puupponen-Pimiä says: “We were especially surprised and excited by the observation that probiotics that are beneficial for digestion are not sensitive to the berries, but harmful bacteria are. Consequently, the berries may inhibit the activity of harmful bacteria. The antimicrobial qualities of the berries are also well preserved e.g. with freezing.” The research team are now investigating ways to extract the compound, and to increase its concentration within berries
