Inhibition of Listeria Monocytogenes on Cold-Smoked Salmon by Edible Antimicrobial Packaging
Every year within the US, 76 million foodborne illnesses are reported with 325,000 hospitalizations and 5000 deaths. Costs associated with foodborne illnesses are approximately $23 billion every year. Over the past 30 years, listeriosis caused by L. monocytogenes has become a major foodborne disease. There are now over 1500 cases of listeriosis reported every year with 260 fatalities. Pregnant women, infants, and people with compromised immune system are at serious risk. Outbreaks of listeriosis in the early 1980s made the FDA and USDA establish a zero policy on Ready-to-eat (RTE) foods in which the occurrence of L. monocytogenes is considered unacceptable. Seafood has often been associated with foodborne listeriosis outbreaks. Occurrence of L. monocytogenes in RTE seafood ranges from 6% to 36% and can even reach 78%. The FDA/USDA risk
assessment included smoked seafood in the list of foods that are at high risk of causing human listeriosis on a per annum basis. Consumer demand for minimally processed seafood has been on the rise. Therefore, there has been a great interest in developing efficient methods to control foodborne pathogens in foods by the use of naturally occurring antimicrobial agents. An alternative approach to control L. monocytogenes is the use of edible films with incorporated antimicrobial systems. Antimicrobial edible films can be used to improve microbiological food safety by reducing the risk of microbiological contamination by prolonged antimicrobial activity on the surface of the food. Edible films are made from various film forming substances that contain protein and carbohydrates. One of the main factors in choosing a raw material for film formation is the cost. The material chosen for
packaging should not add much cost to the product. Potato processing waste is an inexpensive and readily available material. Each year approximately 10 billion pounds of potato processing waste is generated within the United States. Essential oils are volatile aromatic liquids obtained from various plant materials. Use of essential oils to preserve foods can ensure food safety by satisfying the consumers demand for minimally processed or natural foods. Essential oils from oregano, bay laurel, Spanish lavender and fennel show antibacterial activity against various foodborne pathogens. Of the essential oils studied, oregano essential oil has shown more antimicrobial activity against L. monocytogenes. The objectives of the study is to develop potato peel waste-based edible films with incorporated oregano essential oil, determine the physical properties of the films, and study their
antimicrobial activity against L. monocytogenes inoculated onto the surface of cold-smoked salmon. The films have the potential to inhibit L. monocytogenes on cold-smoked salmon and other RTE seafood and thus ensure the safety of the foods. Demonstration of the effectiveness of the films developed in this study will likely increase the use of potato peel waste.