Characterization of tree fruit bacterial communities during harvest

Over the last 40 years there has been a dramatic increase in people's desire to consume fresh fruits and vegetables as a major part of a health diet, for example the per capita consumption of apples in the United States in 1976 was 29.9 lbs. compared to 45.6 lbs. in 2014. However, a recent study by the Centers for Disease Control and Prevention (CDC) attributed 46% of all foodborne infections in the U.S. to fresh produce. Part of the food safety concerns with fresh produce (including tree fruit) is that it is typically consumed raw; therefore it lacks a critical "kill" step to assist in eliminating pathogen contamination prior to consumption. Washing fruits during processing with sanitizers is the only major pathogen removal step; therefore maintaining proper sanitizer levels during the washing process is vital. It has been shown that high levels of cross contamination of fruit can easily occur during the washing process if the sanitizer levels are not maintained properly. Therefore not only is the ability to quickly and accurately detect foodborne pathogen contamination critical, but also systems to determine appropriate times to change sanitizing wash water. The goal of this proposal is to characterize the bacterial communities of tree fruit during pre-harvest, harvest, pre-washing, and post-washing to understand the alterations to the communities during production. Additionally, we will also characterize the viable bacterial communities of tree fruit and alterations due to the introduction of foodborne pathogens. Characterizing and understanding the bacterial communities of tree fruit throughout production and its interactions with foodborne pathogens is vital to improving food safety and helping producers maximize safety. The long-term encompassing goal of this study is to develop a cost-effective, rapid, and highly accurate detection method for foodborne pathogens on various types of tree fruit and other fresh produce utilizing the composition of the bacterial communities. Moreover, the system can also be implemented as a rapid indicator for correct times to change wash water to maximize the sanitizer's effects.