Novel Sterilization Method for Food, Clinical and Pharmaceutical Applications
Foodborne microbial pathogens cause hundreds of thousands of cases of illness and hundreds of deaths in the United States each year. These pathogens cause illnesses ranging from diarrhea and vomiting to much more serious diseases including gastroenteritis, central nervous system disorders, severe bloodstream infections, and life-threatening illnesses such as botulism poisioning. Thus, there is a clear need for better processing and sterilization methods for foods and food packaging. These methods need to be affordable, robust enough to kill even the most resistant pathogens (e.g., bacterial endospores), scalable to industrial size, and have minimal deleterious effects on sterilized materials. Supercritical fluid technologies exhibit genuine promise as sterilization methods due to the fact that it achieves effective microbial lethality, exerts
minimal impact on food quality, generates no waste or effluent, and is already commercialized on an industrial scale (e.g., for decaffeination or denicotinization applications). From work conducted in our laboratory, we have determined that inclusion of small amounts of modifier, such as hydrogen peroxide, has potential to further enhance the lethal effects of SCCD for food preservation and other sterilization applications. The use of modifier in conjunction with SCCD is expected to lessen treatment conditions required to achieve sterilization, thus preserving the quality of treated foods. However, to date, there are very limited studies in the literature regarding the use of modifiers in combination with SCCD for sterilization of food products, or how such combined treatments might affect sterilized microbes and their endospores as well as food quality. Thus, this research proposal is
both novel and unique, and addresses a key issue affecting the state of Idaho and has national significance. The objectives of the proposed research program are to (1) demonstrate that SCCD containing a small amount of modifier (e.g., ~0.1% v/v peroxide) will sterilize raw foods such as meat, poultry, eggs, fish, shellfish, seed-derived foods such as fresh alfalfa sprouts, and fresh vegetables contaminated with bacteria (naturally or purposely), and also show that the technology will sterilize food packaging materials and pre-packaged foods. The second objective is to (2) develop a pilot-scale SCCD system design for testing in collaboration with the commercial food industry. Objective (3) is to develop an educational component of the program that trains graduate Food Science majors in the use of this new technology and the final objective (4) is to elucidate the killing mechanism imposed
by the SCCD treatment on the vegetative cells and bacterial endospores. Knowledge generated from this work will be highly relevant for developing and understanding new sterilization methods as well as training future food science professionals in cutting-edge technologies related to food processing and food safety.