Food Protection Trends

Abstracts - July 2005

Natamycin Control of Yeast Spoilage of Wine

The Internet as a Useful Adjunct during Foodborne Outbreak Investigations

Use of a GMP/GHP HACCP Checklist to Evaluate the Hygienic Status of Traditional Dry Sausage Workshops

Natamycin Control of Yeast Spoilage of Wine

LINDA V. THOMAS,* RICHARD E. INGRAM, HELEN E. BEVIS, PAUL BRIGHTWELL, NICOLA WILSON and JOSS DELVES-BROUGHTON

Danisco Beaminster Ltd., Innovation Department, 15 North Street, Beaminster, Dorset, DT8 3DZ, United Kingdom

SUMMARY
The polyene macrolide natamycin is used worldwide as a natural preservative, mainly for surface treatment of cheese and dried sausages. It is permitted in wine in South Africa, where it is used particularly at the bottling stage in (semi-) sweet wines or wines of low acidity, which are more vulnerable to re-fermentation. High levels of sulfur dioxide and/or sorbate levels are often used in such wines, which have raised health concerns and which also can impair wine quality.

In the present study, yeast strains associated with wine spoilage were shown to be sensitive to low natamycin levels (< 5 mg/l). In preliminary experiments with a commercial red wine (pH 3.4, 13 mg/l free sulfur dioxide, supplemented with 2% glucose), natamycin at 5 to 10 mg/l prevented growth of Candida krusei, Saccharomyces bayanus and Zygosaccharomyces bailii. In a large-scale experiment, the growth of a commercial S. bayanus strain was prevented by 5 mg/l natamycin and the preservative killed yeast cells inoculated into the wine. Natamycin degradation in the wine was faster at ambient temperature (25˚C) than at the temperature of chilled wine (8˚C). At 25 °C the half-life was < 2 weeks and no natamycin was detectable after 3 weeks addition level 10 mg/l), whereas the preservative remained detectable for 19 weeks at 8˚C. This study confirms natamycin effectiveness in wine, demonstrating efficacy against a S. bayanus strain that is now implicated in wine re-fermentation spoilage. Natamycin could increase consumer safety by enabling a decrease in levels of sulfur dioxide and sorbate added to wine, with added benefits to the organoleptic quality of the wine. It could be considered as a processing aid, since at ambient storage it would achieve complete yeast kill before being degraded.

The Internet as a Useful Adjunct during Foodborne Outbreak Investigations

MARK E. BEATTY, *1 LINDA VERCHICK, 3 PATRICIA ROWLEY, 3 BRIAN LABUS, 3 BESS ORMOND, 4
ROSE LEE BELL, 3 CHRISTOPHER BRADEN, 2 and JOHN PAINTER 2

1-Epidemic Intelligence Service, Division of Applied Public Health Training, Epidemiology Program Office, CDC, 1600 Clifton Road Mail Stop A-38, Atlanta, GA 30333, USA
2-Foodborne and Diarrheal Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, CDC, Atlanta, GA 30333, USA
3-Clark County Health District, Las Vegas, NV 89106, USA
4-United States Food and Drug Administration, Seattle, WA 98104, USA

SUMMARY
During a foodborne outbreak investigation in Nevada during 2001, raw oysters were identified as a potential vehicle. Irregularities in record keeping prevented traceback of specific shipments of oysters; however, the Internet provided information useful in locating the source of the oysters. In addition, harvest site closure notices posted on the Internet revealed inconsistencies in the dating of oyster tags at the processor. The Internet provides access to a wealth of information available at Web sites of federal, state, and local agencies, as well as commercial food producers. This information can be useful during outbreak investigations.

Use of a GMP/GHP HACCP Checklist to Evaluate the Hygienic Status of Traditional Dry Sausage Workshops

Silvina Fadda, 1 Teresa Aymerich, 1 Marta Hugas, 2 and Margarita Garriga 1*

1-CERELA – CONICET, Chacabuco 145, 4000 San Miguel de Tucumán, Argentina
2-European Food Safety Authority (EFSA), Largo N. Palli 5/A, I-43100 Parma

SUMMARY
The purpose of this work was to evaluate the hygienic status and the feasibility of implementing a self-control system in ten traditional dry sausage workshops in Catalonia (Spain). A Good Manufacturing and Hygienic Practice checklist based upon HACCP principles was incorporated into a questionnaire. It included topics related to pre-requisites of a self-control system, critical points of the process and the efficiency of the hygiene program used at their facilities. In addition, analyses of spoilage/pathogen flora in environmental samples and products, as well as measurements of temperature and relative humidity, were carried out at several facilities. After the questionnaire had been completed, traditional workshops were ranked. All workshops studied presented adequate infrastructures for implementation of a self-control system. In general, cold rooms and mixing machines were classified as “ultraclean” (0–2 x 10 2Enterobacteriaceae CFU/100 cm 2) and no pathogens were detected in them. Stuffing machines received a “not clean” denomination (> 10 3Enterobacteriaceae CFU/100 cm 2), with Listeria monocytogenes present in 20% of these. Pathogen concentrations of dry sausages from all workshops studied were below pre-established limits (Salmonella and Escherichia coli verotoxigenic (VTEC): not detected in 25 g; L. monocytogenes: < 100 CFU/g; Staphylococcus aureus: < 500 CFU/g). All producers reached a “sufficient” classification according to the criteria established, although some aspects (high temperature, low humidity of meat reception/storage areas, excessive time for casing desalting, and presence of L. monocytogenes in some machines) should be corrected. A systematic application of this kind of HACCP checklist could help small producers to improve the hygienic quality of their facilities and products.