Virginia Polytechnic Institute and State University

Susan Duncan, Dairy and Sensory Evaluation

Bill Eigel,                Food Biochemistry

Joe Marcy:               Food Processing

Merle Pierson: Food Microbiology

 Sean O’Keefe: Food Chemistry

Susan Sumner:   Food Safety

Walter Hartman:    Dairy Plant Manager whartman@vt.edu

Kim Waterman:  Dairy Chemistry    Kwater@vt.edu

Brian Yaun: Microbiology byaun@vt.edu           Phone: (540) 231-8697

Current research at virginia tech

 Survival of Listeria monocytogenes in Fruit Juices During Refrigeration and Temperature-Abusive Storage

   Survival of Listeria monocytogenes in apple, orange, red grape, and white grape juice was evaluated in a recent study conducted by researchers in the Department of Food Science and Technology. 

   A six-strain cocktail of L. monocytogenes (containing approximately 7 log cfu/ml) was used to inoculate fruit juices, which were then stored at 4, 10 and 24° C for up to 61 days.  Inoculated red grape juice was stored for up to 5 hours only.  Samples were withdrawn at appropriate intervals, neutralized with 1.0 N NaOH, serially diluted in 0.1% peptone water, and surface plated onto tryptic soy agar + 0.6% yeast extract (TSAYE) and Modified Oxford Agar (MOX), followed by incubation at 32° C for 48 hours.    

   When no longer detected by direct plating, samples were enriched for L. monocytogenes using Listeria Enrichment Broth (LEB), followed by isolation on MOX. L. monocytogenes remained viable in white grape, apple, and orange juices for up to 12, 24 and 61 days, respectively.  Generally, over time, recovery on TSAYE versus MOX was not significantly different (P>0.05), indicating that little acid injury developed during storage. 

   The results of this study demonstrate that L. monocytogenes is able to survive in apple, orange, and white grape juices during refrigeration and abusive storage conditions.  It is important for juice processors to have measures in place to minimize or eliminate L. monocytogenes in juice-processing surroundings.  Processor awareness of and preventative steps are necessary to ensure the safety of juice products for public consumption. 

HOT TOPICS AND DAIRY ISSUES

Juice HACCP Regulation:  Questions and Answers- Continued

    In August, 2001, FDA published “The Juice HACCP Regulation Questions and Answers”, to be used as an industry guide in understanding the 2001 FDA rule that requires processors of juice to develop and implement HACCP systems for their operations.  Due to a high level of interest in last month’s newsletter, more FDA responses to frequently asked questions follow.

    How many critical control points (CCPs) should there be in a HACCP plan?  A HACCP plan need only have as many CCPs as the processor deems necessary to control the hazards that are reasonably likely to occur.  How often should a juice manufacturer validate their HACCP plan(s)?  Each HACCP plan must be validated at least once within 12 months after implementation and no less than every 12 months thereafter.  Validation will also be necessary when any changes have occurred in the process that might affect the hazard analysis or alter the HACCP plan in any way.  Will FDA recommend or certify labs for processing and end product testing of juices in order to verify the reliability of the testing data?  No. Processors are responsible for choosing labs that are able to perform appropriate, accurate tests.  Will Clean-In-Place (CIP) recording charts be required for juice fillers in order to provide records and verify cleaning under the mandatory equipment cleaning SSOP?  CIP recording charts are not required.  The processor is only required to maintain records that document the monitoring and corrective actions prescribed.  Since processors of shelf-stable and thermally concentrated juice are already controlling a majority of their hazards, are they required to have as much HACCP training as other juice processors?  All processors subject to the regulation must comply with the training requirements of the regulation, regardless of what type of product they process.  Are foreign processors subject to the regulation?  Yes. Both domestic and foreign juice processors that ship juice products to the U.S. are subject to the regulation.  Are importers required to ensure that the juice ingredient in a beverage has been processed in accordance with the regulation?  No.  Importers of beverages that contain juice (e.g., dilute juice beverages) are not covered.  Will FDA conduct on-site inspections of foreign juice processors?  Yes.  FDA does conduct some inspections of foreign firms, including juice firms.  If paperwork from an importer indicates that a particular lot of juice concentrate has a deviation and corrective action, can that concentrate be co-mingled with domestic concentrate for use in a pasteurized juice?  Yes.  The concentrate can be co-mingled provided that corrective action was taken using an appropriate corrective action plan.  An appropriate corrective action plan is one that describes the steps to be taken and assigns responsibility for taking those steps, to ensure that “no product enters commerce that is either injurious to health or is otherwise adulterated as a result of the deviation” and “the cause of the deviation is corrected”.  Do milk pasteurization times and temperatures provide sufficient heat treatment to meet the 5-log pathogen reduction requirement for juice?  Pasteurization times and temperatures to achieve a 5-log reduction will vary depending on the type of product, the process, target microorganism, product pH, etc.  In most cases, milk pasteurization conditions of 161 degrees for 15 seconds will achieve a 5-log pathogen reduction for juice.  However, the processor must show that the validated HACCP plan (including processing conditions) is adequate to control food safety hazards that are reasonably likely to occur in that product.  I am a dairy processor who purchases juice concentrate from a concentrator and reconstitutes it to a single strength juice prior to packaging. Is a 5-log reduction at the concentrator’s facility sufficient to address the 5-log performance standard?  No.  You must treat the juice to achieve a 5-log reduction prior to final packaging.  The 5-log exemption only applies when the product is processed and packaged at a single facility.  If I purchase a fruit puree that has been treated to achieve a 5-log reduction and blend it with juice that I have manufactured and treated to achieve a 5-log reduction, does the resulting blend need to be treated again to achieve a 5-log reduction?  Yes. The blended juice, including the puree, must receive a 5-log treatment at the final packaging facility.  What processing treatment and temperature is required for a juice to be considered shelf-stable?  A product is shelf-stable if it is hermetically sealed, and if it does not demonstrate microbial growth when it is stored at room temperature.  The regulation does not provide for specific processing parameters for attaining shelf-stability.

   More information on conducting a hazard analysis can be found in the National Advisory Committee on Microbiological Criteria for Foods (NACMCF) publication, “Hazard Analysis and Critical Control Point Principles and Application Guidelines”, Journal of Food Protection, Vol. 61, No. 9, pp. 1246-1259 (1998), and FDA’s Juice HACCP Hazards and Controls Guide.