Submitted to: American Society for Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/22/2002
Publication Date: 5/19/2002
Citation: Hinton Jr, A., Cason Jr, J.A., Ingram, K.D. 2002. Yeasts associated with chilling operations in a commercial poultry processing plant. [abstract] American Society for Microbiology Annual Meeting.
Interpretive Summary: Chilling operations in poultry processing plants reduce the temperature of the carcasses and help the poultry meat stay fresher longer. In some processing plants carcasses are chilled by immersing the carcasses in ice water. In the present study, experiments were conducted to determine the number and types of yeasts associated with poultry carcasses before and after immersion chilling. Yeasts were recovered from prechilled and chilled poultry carcasses by rinsing each carcass for 1 min. The rinsates were collected, and the number of yeasts in the rinsates were determined. The types of yeasts recovered from the carcasses were also identified. Findings from the experiments indicated that chilling does not produce significant changes in the number of yeasts on the poultry carcasses. Additionally, different types of yeasts were isolated from prechilled and chilled carcasses. Four types of yeast were isolates from prechilled carcasses and 3 types of yeasts were isolates from chilled carcasses. No yeasts were isolated from chilled carcasses in 2 of the 4 trials. Determining the types and number of yeasts associated with various phases of poultry processing may provide information that can be used to reduce the growth of the microorganisms on poultry carcasses and extend the shelf life of poultry.
Technical Abstract: Experiments were conducted to enumerate and identify yeasts associated with immersion chilling operations in a commercial poultry processing plant. Yeasts were recovered from prechilled and chilled poultry carcasses by rinsing each carcass in 300 ml of peptone water for 1 min. Yeasts in the rinsates were enumerated by plating serial dilutions of the rinsates on acidified Potato Dextrose Agar and incubating at 28C for 3 days. Colony-forming-units were counted, and colonies were streaked onto Sabouraud Dextrose Agar (SDA) and incubated at 28C for 24 h. Yeast isolates grown on SDA were identified with the MIDI Sherlock Microbial Identification System. Findings indicated that chilling produced no significant change in the number of yeasts recovered from the carcasses. However, chilling reduced the size of the yeasts population to undetectable levels in two trials. Furthermore, different types of yeasts were isolated from prechilled and chilled carcasses within the same trial. Isolates from prechilled carcasses included Candida species in Trials 1 and 4, Cryptococcus species in Trials 3 and 4, Yarrowia lipolytica in Trial 4, and an unidentified yeast in Trial 2. Isolates from chilled carcasses included Candida species Trials 2 and 4, Kluyveromyces marxianus in Trial 2, and Zygosaccharomyces bailii in Trial 4. No yeasts were isolated from chilled carcasses in Trials 1 and 3. Determining the types and number of yeasts associated with various phases of poultry processing may provide information that can be used to inhibit or control the growth of the microorganisms on poultry carcasses. Limiting the growth of yeasts on the carcasses may extend the shelf life of fresh poultry.