TrackNSolve – Methodology to track and solve microbial issues in dairies

The dairy industry is continually faced by safety, quality and spoilage issues due to growth or activity of microorganisms. Traditional root cause analysis is slow and/or unable to identify the responsible microorganism(s), leading to defects and waste of products. The objective of this project is to develop a diagnostic methodology that enables the industry to rapidly identify, detect, and mitigate microbial issues.

By: Grith Mortensen

TrackNSolve will focus on two relevant microbial problems, i.e., spoilage of UHT milk by heat resistant bacterial enzymes and undesirable formation of nitrite in milk concentrates and powder. UHT milk retains the quality under non-refrigerated conditions. UHT eliminates microorganisms, but some bacterial spores and enzymes survive including proteases such as AprX, which is produced by Pseudomonas spp. and has been shown to spoil UHT milk. The presence of nitrates and nitrites can be a chemical hazard for milk powders. These oxidized nitrogen compounds can be derived from ingestion of nitrates and nitrites by dairy cows during grazing, during the sanitization of dairy equipment, and conversion of nitrate to nitrite by nitrate reducing microorganisms. Existing knowledge of microbial formation of nitrite during dairy powder production is limited.

TrackNSolve consists of three investigative steps that combines metagenomics, phenotypic information, and microbial genetics to determine: 1) WHO are there? 2) WHO is causing the problem? and 3) HOW can the responsible problem organisms be detected by a molecular method (PCR) to enable timely mitigation? The usefulness of the approach will be demonstrated by solving two common microbial problems, i.e., spoilage of UHT milk by heat resistant bacterial enzymes and undesirable formation of nitrite in milk concentrates and powder. In the case of UHT milk, results from a previous DDRF project (MicroLink) will allow us to go straight to Step 3 and focus on design of a PCR method for detection of protease producing Pseudomonas spp. In the case of nitrite, all three steps will be applied to solve the problem.

TrackNSolve will solve two commonly encountered quality issues of microbial origin and make two molecular detection methods available for routine monitoring purposes in the dairy industry. The outcome of the project will create a methodology for rapid identification of problem microorganism(s) to allow for timely mitigation. This will make the dairy industry better equipped to quickly resolve cases of microbial quality and safety issues, which will ultimately reduce food waste.