Potential sources of error during virus thermal inactivation

Area of Science:

• Microbiology
• Food Science
• Public Health

Background:

• Virus thermal inactivation studies are crucial for food safety and public health.
• Published literature shows variability in reported virus resistance to heat.
• Many studies historically used test tubes for heat processing virus suspensions.

Purpose of the Study:

• To review virus thermal inactivation data.
• To identify methodological factors contributing to variations in reported virus resistance.
• To investigate the impact of heating methods on virus inactivation.

Main Methods:

• Literature review of virus thermal inactivation studies.
• Replication of specific heating methods using milk suspensions of poliovirus 1.
• Analysis of temperature distribution within test tubes during heating.

Main Results:

• Significant variations in reported virus thermal resistance were observed in the literature.
• Heating virus suspensions in test tubes resulted in uneven temperature distribution.
• This uneven heating led to apparent poliovirus persistence, even after processing.
• Proper submersion and agitation of sealed containers are critical for accurate results.

Conclusions:

• Methodological inconsistencies, particularly the use of test tubes, can lead to inaccurate virus thermal inactivation data.
• Apparent virus persistence may be an artifact of experimental setup rather than true heat resistance.
• Standardized methods ensuring uniform heating are essential for reliable virus inactivation studies.