Assessing refrigerated preservation performance using Listeria predictive microbiology models and temperature data:...

Area of Science:

• Food Science
• Microbiology
• Engineering

Background:

• Domestic refrigerators frequently operate above recommended temperatures, compromising food safety.
• Listeria monocytogenes poses a significant risk in refrigerated foods like queso fresco.
• Existing methods for assessing refrigerator performance lack quantitative microbial preservation indicators.

Purpose of the Study:

• To develop and apply a quantitative tool, the refrigerator performance indicator (RPI), for assessing microbial preservation in queso fresco.
• To evaluate the impact of compressor technology, ambient temperature, and refrigerator load on RPI.
• To provide practical insights for improving refrigerator design and consumer practices.

Main Methods:

• Utilized time-temperature data from queso fresco stored in refrigerators at 5°C.
• Employed a predictive microbiology secondary model for Listeria monocytogenes.
• Calculated deterministic and probabilistic RPI values to assess preservation performance.

Main Results:

• All RPI estimations slightly exceeded the ideal value of 1.0, indicating suboptimal preservation.
• Ambient temperature was the most significant factor affecting refrigerator performance, especially during door openings.
• Compressor technology and load also influenced preservation, but to a lesser extent than ambient temperature.

Conclusions:

• The RPI is a viable quantitative tool for assessing refrigerator microbial preservation performance.
• Improving compressor operation logic and reducing product exposure to ambient temperatures are key for enhanced food safety.
• Consumer education on door opening habits can significantly improve refrigerator performance and reduce microbial risks.