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25. Early detection and risk-based analysis of Lactobacillus and Pediococcus contamination enables preventive quality and environmental monitoring programs at the brewery

K. M. KAHLE (1), Z. Miller (2), A. Bartles (2), J. J. Lindsey (1), M. K. Feeney (1), S. P. Terkhorn (1), N. A. Siciliano (1); (1) Invisible Sentinel, Inc., Philadelphia, PA, U.S.A.; (2) Victory Brewing Co., Downingtown, PA, U.S.A.

Enzymes, Finishing and Stability
Friday, October 9
8:00–9:45 a.m.
River Terrace 2

A major challenge in maintaining beer quality is early detection of spoilage microorganisms before they have the ability to produce unintended flavors and aromas. Spoilage organisms can be diverse and present different quality risks based on their potential to thrive in beer and in the brewery. Early detection coupled with risk-based analyses can provide invaluable information to quality-centric brewers. A novel molecular diagnostic assay, Veriflow brewPAL, was developed to provide accurate and sensitive detection of beer spoiling Pediococcus and Lactobacillus species in under 3 hr. Veriflow brewPAL is a DNA signature-capturing technology that specifically detects beer spoilers via hop resistance genes without the need for bacterial enrichment or DNA purification. This assay is versatile and can be employed to evaluate samples collected throughout the brewing process, from raw materials to finished product. Speed to results, specificity, and sensitivity are paramount for early detection in order to quickly provide actionable information and effectively preserve quality. Due to the unprecedented speed of the assay, brewPAL can shift the brewery spoilage monitoring paradigm from reactive to preventive. brewPAL has provided brewers with unique value by analyzing bright tank beer prepackaging and allowing them to implement environmental monitoring programs. Numerous factors can influence the ability of Lactobacillus and Pediococcus species to metabolize and affect the quality of beer, including levels of hop resistance factors and percent ABV, IBU, and pH of the beer. The effects of these factors on Lactobacillus and Pediococcus growth kinetics were evaluated to develop a model for beer spoilage risk assessment. A Pediococcus and Lactobacillus risk index (PAL score) was developed using quantified brewPAL results to assess the potential for bacterial outgrowth and spoilage. This scoring system can be used as a tool to help predict whether conditions within a particular beer are favorable for rapid bacterial growth and subsequent spoilage, thereby providing brewers with the ability to make early and informed decisions to maintain the quality of their products.

Kristen Kahle is the director of research at Invisible Sentinel, a global molecular solutions company that provides microbial diagnostic tools for multiple industries, including food safety and beverage quality. At Invisible Sentinel, Kristen leads the scientific team that developed brewPAL, a rapid molecular test for the detection of beer spoilage organisms, in partnership with Victory Brewing Company. Kristen specializes in the development of quantitative assays to identify spoilage organisms and has successfully commercialized new technologies for data analysis. She earned her M.S. degree in biotechnology from Pennsylvania State University and a Ph.D. degree in molecular pharmacology and structural biology at Thomas Jefferson University. Kristen has extensive experience investigating viral and microbial pathogens and resistance mechanisms and previously designed inhibitors to mitigate the effects of these biological agents. She has numerous publications in the field of microbiology and host–pathogen interactions.