Antimicrobial activity of five spices against foodborne bacterias

Research has demonstrated that water extracts of some common food spices, were capable of inhibiting food spoilage microorganisms.  New formulated food preservative can be used as natural and niche preservatives for the food industry.

The antimicrobial activity of water extracts of five spices against five common meat spoilage and pathogenic bacteria was screened in cultured media from fresh sirloin steak.

The five spices are cinnamon, clove, star anise, picklyash peel and common fennel. Total coliforms were selected as indicators reflecting the freshness of sirloin steak.

Based on the antimicrobial tests on water extract of individual plant, a new food preservative formula was designed as mixture of the five plant water extracts with chitosan, the optimized concentration of which was determined by experimental uniform design as 0.2 g/L (cinnamon), 3.0 g/L (clove), 0.7 g/L (picklyash peel), 2.2 g/L (star anise), 0.6 g/L (common fennel) and 1.9 g/L (chitosan).

Examination showed that chilled steak samples treated with the new food preservative mixture remained fresh after 9 days of storage, which suggested the new naturally originated preservative being potential in practical application by food industries.

These spices are useful preservatives to inhibit microbe. In order to avoid toxicity and possible negative effects on the structure of meat and protein denaturation caused by essential oils and ethanol extracts, distilled water was used as the extraction agent in this study. In addition, a new naturally originated food preservative formula was designed as mixture of water extracts of the five plants with chitosan.

The chilled steak samples treated by the new food preservative remained fresh after 9 days of storage. 

These spice extracts as well as the new food preservative can be widely used in the food industry and are generally regarded as safe. Thus, spice extracts and the new formulated food preservative in this study can be used as natural and niche preservatives for the food industry.


Journal of Food Processing and Preservation

Listeria-busting discovery could be adapted for processing plants

Research that may lead to a human drug to combat Listeria monocytogenes could also be adapted to fight the deadly bug in food processing plants

Scientists have discovered a compound that stops Listeria from transforming itself from a harmless microbe into a potentially lethal human pathogen.Listeriosis is responsible for 10% of all deaths in the US from foodborne diseases.

The substance called fluoro-phenyl-styrene-sulfonamide (FPSS) hinders the bacteria’s ability to survive a raft of “environmental assaults” thrown at it from rapid changes in temperatures during food production and storage to highly acidic stomach conditions and osmotic and anaerobic states in the small intestines.

Scientist found Listeria has developed an anti-stress capacity called sigma B. This “stress responsive alternative factor” controls more than 150 genes which are key in its capabilities connected to factors such as virulence and survival in hosts.

The research, published in the November/December issue of mBio, a journal of the American Society for Microbiology, could lead to the development of a human drug to fight against Listeria and other bacterial infections.

Prof. Boor say: “It is reasonable to hypothesize that treatment of surfaces with FPSS could make Listeria monocytogenes that might contaminate such a treated surface easier to kill, as the organism would be likely to be impaired in its ability to respond to environmental stresses, such as treatment with sanitizers,” she said.

The project was part of a “newly emerging approach in the search for antibiotics that are not dangerous to mammals but stop such pathogens as Listeria, and could be a possible treatment against other organisms”.

She added that further research was needed to better understand how FSPP controls sigma B activity and whether the compound affects the same mechanism in such pathogens as Bacillus  cereus (foodborne illness), Staphylococcus aureus (cause of acne and pneumonia) and Bacillus anthracis (anthrax).
Source: foodproductiondaily.com
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