Technology Review: Innovation in Microbial Interventions
Forgive the pun, but there are some killer microbial intervention technologies on the market that are of keen interest to the food industry. The number of commercially available thermal, non-thermal, antimicrobial chemical and other novel treatments applied to foods and/or food-contact surfaces designed to inhibit, reduce or inactivate microorganisms has never been greater—or more in demand by food manufacturing operations.
What has driven a surge in the development and availability of new and improved interventions? Certainly, part of the answer is that regulatory, industry and research institutions have formed a strong partnership supporting the use of quantitative microbial risk assessments to identify critical points within the food chain at which effective interventions will have the greatest impact on reducing foodborne illness. Several of the U.S. Food and Drug Administration’s (FDA) and the U.S. Department of Agriculture’s (USDA) more recent industry guidelines, directives and proposed rules reflect this unified push to apply intervention technologies to improve food safety. FDA’s 2004 Produce Safety Action Plan, for example, identifies as part of the agency’s objectives the promotion of risk assessments to identify with industry the microbial interventions that will be most effective in produce operations.
Similarly, USDA’s Food Safety and Inspection Service (FSIS) interim final rule on the control of Listeria monocytogenes in ready-to-eat (RTE) meat and poultry products (Directive 10,240.4) provides incentives for RTE producers to use post-lethality treatments, antimicrobials ingredients at formulation and other intervention technologies to significantly reduce the risk of the presence or growth of Listeria on these products. And, industry has been vocal in expressing its desire that new intervention strategies receive expedited regulatory agency review, as companies search for viable options that will improve their ability to prevent, control and eliminate undesirable microorganisms through HACCP, GMP and other food safety programs.
As Food Safety Magazine’s editors have traveled the country this year, we’ve been introduced to several innovative, new or improved technologies and systems designed for use as part of the multi-hurdle intervention approachto food safety. Here, we’ll highlight some of these in-plant thermal, non-thermal, chemical and novel microbial intervention systems as a quick guide to the latest advances in this important area of food safety.
Hot Thermal Interventions
Applying heat to foods and food-contact surfaces, either as a validated kill step or as a pathogen reduction method, is the classic means by which to achieve processing, packaging and post-packaging intervention. From steam treatments to dry heat to cook steps, the higher the temperatures applied, the higher the confidence that bacteria have been destroyed. For some foods, however, heat treatments can have an adverse affect on the quality attributes of finished product, such as minimally processed fruits and vegetables. Some of the newer microbial intervention technologies are designed with this issue in mind and thus are capturing the attention of food manufacturers nationwide.
One such thermal technology, Biosteam Technologies, Inc.’s trademarked ThermoSafe system, is a pasteurization method that has proven effective in the area of surface decontamination of fruits and vegetables destined for further processing, including fresh juice, cut fruit and melons, fruit concentrates and smoothies. The company reports that research conducted by Food Safety Net Services, Ltd., an ISO/IEC 17025 accredited network of laboratories, shows that the ThermoSafe process can be effective in reducing the microbial load of Listeria monocytogenes, Salmonella spp., E. coli O157:H7, and Lactobacillus spp. on the surface of fruits and vegetables by 5 logs, and in some cases, up to 9 logs. In addition to the safety factor of the process, studies indicate taste panels were able to determine a sweeter flavor from the steamed fruit over the control or unsteamed product.
In describing the process, Biosteam notes that the ThermoSafe process uses time and temperature settings, depending on the commodity, to facilitate the desired microbial intervention step. The system can serve to clean and sanitize both products and equipment in minutes, automatically ending the sanitizing cycle at a predetermined temperature. This technology is designed to provide the user with a constant supply of steam, whether in the form of a portable unit or a large scale in-line applications system.
Similarly, ALKAR-RapidPak’s Surface Pasteurization Technology (RP-SP) is designed to produce safer food products without loss of desirable product sensory characteristics. This flash pasteurization system promises a 3-log reduction for Listeria monocytogenes, for example, with no formula change required and no effect on packaging films. While a conventional pasteurization method essentially recooks product, taking between four to 20 minutes of application time that must be followed by re-chilling, the RP-SP is designed to achieve surface pasteurization in 1.5 seconds. The system module uses bursts of steam and a jostling mechanism to pasteurize all surfaces of food products, followed by the injection of rapid bursts of high-pressure steam.