Researchers at the University of Maine examined the potential for cranberry concentrate (CC) to be used as a natural food preservative by examining its antimicrobial effect on the growth of Escherichia coli O157:H7 inoculated in ground beef as well as its organoleptical effect on beef burgers.
The findings of the research, which was published in the journal Food Microbiology, indicated that cranberry concentrate at the tested concentrations did not cause significant negative impact on the flavour, taste or colour of burgers and also possessed antimicrobial effects.
The application of cranberry concentrate at low concentrations in ground beef as an additional hurdle to prevent possible E. coli O157:H7 contamination has not been previously reported, claim the authors.
Ground beef is a potentially hazardous food which can harbour pathogenic microorganisms and permit their growth or the production of toxins if temperature and time are not controlled, claim the authors of the study.
E. coli O157:H7 can survive in healthy cow guts and may contaminate beef when cows are slaughtered.
In the US this year, millions of pounds of raw ground beef were recalled because of E. coli O157:H7 contamination, and the researchers stress that effective methods to prevent and eliminate such contaminations in ground beef are as such essential for the food industry and consumers.
Consumers today tend to choose food products that are natural, safe, and with multi-health benefits; burgers with cranberry concentrate, according to the researchers, may be a product that can meet their requirements.
The article reports that American cranberries (Vaccinium macrocarpon) contain many bioactive compounds that have antioxidant, anti-mutagenic, antihypercholesterolemic and other beneficial health properties.
However, the authors said that they included sensory evaluation as part of their research to determine if consumers would accept the organoleptical properties of ground beef inoculated with cranberry concentrate.
Inoculated ground beef was added with CC and stored at 4°C for five days, said the authors.
Cranberry concentrate (2.5 per cent, 5 per cent, and 7.5 per cent w/w) reduced E. coli O157:H7 population by 0.4 log, 0.7 log, and 2.4 log, respectively, when compared to the control on day five, claims the team.
They added that the inhibition effect of cranberry concentrate increased with time and concentration.
In addition, 50 panelists evaluated the burgers supplemented with CC, and no differences in appearance, flavour, and taste were found among burgers with 0 per cent, 2.5 per cent, and 5 per cent CC.
Source: Food Microbiology Published online ahead of printTitle: Application of cranberry concentrate (Vaccinium macrocarpon) to control Escherichia coli O157:H7 in ground beef and its antimicrobial mechanism related to the downregulated slp, hdeA and cfaAuthors: V. C.H. Wu, X Qiu, B. G. de los Reyes, C.S. Lin, Y. Pan