Salmonella and Cronobacter sakazakii are two leading causes of foodborne illness associated with low-moisture foods, including infant formula. Both causative organisms can persist in food manufacturing processing environments and contaminate finished product if programs are not in place to limit their introduction and control their spread. An environmental sampling and monitoring program is an important tool that food manufacturers use to determine the effectiveness of their sanitation practices and pathogen control efforts. Guidance for initiating an environmental sampling plan and evaluating the plan is lacking. The objective of this study was to develop microbiological environmental sampling plans based on the answers to a series of questions related to product hazards, processing risks and controls, and knowledge of appropriate microbiological sampling and testing protocols. Furthermore, these initial sampling plans were related to the volume of product and size of the processing facility.  An interactive spreadsheet tool for designing sampling monitoring plans for an infant formula process was developed using Microsoft Excel. Additionally, the tool can be used to record qualitative and quantitative sample test results, and to alert the user how the upcoming sampling plan will be changed, if necessary, based on monthly test summaries. The sampling tool provides a simple method for selecting an appropriate environmental sampling plan (samples per zone per month) and provides a rationale and guidance for creating and modifying these plans.  Effective sampling plans and trend analysis of sample test results support the food processors decisions for implementing controls to enhance food safety. / Master of Science in Life Sciences

Unsaturated fats undergo a process known as oxidation by which they are degraded into undesirable compounds. Therefore it is important for food manufacturers to employ antioxidant strategies. Crackers were used as a model in these studies because of their dietary contribution to saturated, and because the properties of crackers are translatable to other low moisture foods. The objective of this thesis was to determine if there was a significant variance in rates of oxidation between surface and total lipids in crackers and how solid fat content, synthetic antioxidants, and reduction of headspace oxygen affect those rates. It was hypothesized that lipids on the surface of a cracker would be more prone to oxidation than those on the interior. Experiments consisted of treatments to monitor total lipid oxidation and surface lipid oxidation. In the first experiment, crackers were formulated with soy oils of varying solid fat content. The second experiment monitored the effects of two synthetic antioxidants, BHT and TBHQ. The third experiment involved flushing the headspace of cracker storage vials with different blends of nitrogen and oxygen to inhibit lipid oxidation. Overall, significant differences did not exist in the rates of oxidation between surface and interior lipids. The lower the solid fat content of an oil, the more prone it was to oxidation. Antioxidants of greater hydrophobicity have increased efficacy in low moisture foods. Greater than 70% oxygen reduction is necessary to impart any antioxidant effect on crackers.