Mild heat and freezing to lessen bacterial numbers on chicken liver1

Abstract

Summary: Foodborne campylobacteriosis has been traced to undercooked chicken liver. We have detected Campylobacter in raw chicken livers from retail and processing plant samples. In the current study, we tested a 1 or 5 min 60°C heat treatment, a 48 h −25°C freeze treatment, and a combination of both as a means to pasteurize raw chicken liver lobes. We cultured treated and untreated liver lobes to determine numbers of Campylobacter and total aerobic bacteria. Overall, the 1 min heat treatment was ineffective. The 5 min heat treatment significantly lowered Campylobacter numbers. Freezing was also moderately effective. The combination of both heating and freezing resulted in nearly 99% decrease in Campylobacter numbers but was accompanied by significant lightening of the liver tissue. A mild heat treatment with or without subsequent freezing will not assure elimination of Campylobacter but may lessen consumer risk because of exposure in kitchen and during meal preparation.

Keywords

• Campylobacter
• chicken liver
• color
• freezing
• heat