Article

Strategy to inactivate Clostridium perfringens spores in meat products

Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA.
Food Microbiology (Impact Factor: 3.37). 05/2009; 26(3):272-7. DOI: 10.1016/j.fm.2008.12.011
Source: PubMed

ABSTRACT The current study aimed to develop an inactivation strategy for Clostridium perfringens spores in meat through a combination of spore activation at low pressure (100-200 MPa, 7 min) and elevated temperature (80 °C, 10 min); spore germination at high temperatures (55, 60 or 65 °C); and inactivation of germinated spores with elevated temperatures (80 and 90 °C, 10 and 20 min) and high pressure (586 MPa, at 23 and 73 °C, 10 min). Low pressures (100-200 MPa) were insufficient to efficiently activate C. perfringens spores for germination. However, C. perfringens spores were efficiently activated with elevated temperature (80 °C, 10 min), and germinated at temperatures lethal for vegetative cells (≥55 °C) when incubated for 60 min with a mixture of l-asparagine and KCl (AK) in phosphate buffer (pH 7) and in poultry meat. Inactivation of spores (∼4 decimal reduction) in meat by elevated temperatures (80-90 °C for 20 min) required a long germination period (55 °C for 60 min). However, similar inactivation level was reached with shorter germination period (55 °C for 15 min) when spore contaminated-meat was treated with pressure-assisted thermal processing (568 MPa, 73 °C, 10 min). Therefore, the most efficient strategy to inactivate C. perfringens spores in poultry meat containing 50 mM AK consisted: (i) a primary heat treatment (80 °C, 10 min) to pasteurize and denature the meat proteins and to activate C. perfringens spores for germination; (ii) cooling of the product to 55 °C in about 20 min and further incubation at 55 °C for about 15 min for spore germination; and (iii) inactivation of germinated spores by pressure-assisted thermal processing (586 MPa at 73 °C for 10 min). Collectively, this study demonstrates the feasibility of an alternative and novel strategy to inactivate C. perfringens spores in meat products formulated with germinants specific for C. perfringens.

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    • "D 100 °C -values around 20 min were determined in beef gravy for C. perfringens spores (Juneja et al., 2003), the same D-value of C. botulinum spores at 101 °C. These findings promoted research on the C. perfringens risk assessment on ready-to-eat and partially cooked meat and poultry products and its spore inactivation in different foods (Akhtar et al., 2009; Crouch et al., 2009; Gao et al., 2011; Golden et al., 2009; Varga and Szigeti, 2012). The ultrasound technology has a large number of applications in food processing such as defoaming, emulsification, extrusion, extraction , and waste treatment (Feng and Yang, 2011). "
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    • "For example, spores of C. perfringens type A food poisoning isolates, unlike those of non-food borne isolates, are able to germinate in the presence of co-germinants Na þ and Pi or K þ ions. These minerals are intrinsically present in meat and processed meat products, and might significantly contribute to germination, outgrowth and proliferation in the meat during temperature abusive conditions [4]. Similarly, C. difficile spores mainly germinate in the presence of taurocholate ubiquitously found in the intestinal tract of animals and humans; however, due to the aerobic nature of the small intestine, growth is arrested. "
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    • "HPP is not without its limitations however. It is generally ineffective against bacterial spores (Akhtar et al. 2009; Shearer et al. 2000) and commercial HPP equipment is expensive. As a result, its application is generally limited to refrigerated foods and for use by high throughput commercial operations. "
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