Publications

Authors:

Rossi, Franca; Gaio, E; Torriani, Sandra

Title:

Staphylococcus aureus and Zygosaccharomyces bailii as primary microbial contaminants of a spoiled herbal food supplement and evaluation of their survival during shelf life.

Year:

2010

Type of item:

Articolo in Rivista

Tipologia ANVUR:

Articolo su rivista

Language:

Inglese

Referee:

Sì

Name of journal:

FOOD MICROBIOLOGY

ISSN of journal:

0740-0020

N° Volume:

27

Number or Folder:

3

Page numbers:

356-362

Keyword:

Herbal food supplement; Microbial contaminants; S. aureus; Z. bailii; Contamination source; Ingredients

Short description of contents:

This investigation was carried out to identify the microbiota in a spoiled commercial food supplement consisting of a syrup suspension of a mixture of dried herbs and herb extracts. The product did not contain alkyl-p-hydroxybenzoates (parabens) as preservatives, was kept at room temperature and showed abundant gas formation. Colonies of distinct morphology were recovered on bacteria- and yeast-specific media, and tested for their ability to grow in the product. Genetic differentiation and identification of the microbial contaminants were achieved by RAPD-PCR and rDNA sequence analysis. The bacteria Bacillus megaterium, Bacillus subtilis, Paenibacillus humicus, Paenibacillus glycanilyticus, Staphylococcus aureus, Staphylococcus epidermidis and the yeasts Zygosaccharomyces rouxii and Zygosaccharomyces bailii were detected. Of the two S. aureus strains isolated, one was enterotoxigenic, as indicated by the presence of five SE genes. Quantitative Real-Time PCR tests, specific for this pathogen and for Z. bailii, a microbial agent causing fermentation processes and consequent food spoilage, were carried out to quantify these microorganisms in the product and identify their source among the herbal ingredients and the fructose syrup used as sweetener. Most components appeared to be contaminated by both S. aureus and Z. bailii. These findings indicate the need to improve hygienic practices in the industrial manufacturing of the food supplement, starting with herbal ingredients, to ensure a high quality of the product.

Product ID:

56096

Handle IRIS:

11562/342105

Deposited On:

July 6, 2012

Last Modified:

November 9, 2022

Bibliographic citation:

Rossi, Franca; Gaio, E; Torriani, Sandra, Staphylococcus aureus and Zygosaccharomyces bailii as primary microbial contaminants of a spoiled herbal food supplement and evaluation of their survival during shelf life. «FOOD MICROBIOLOGY» , vol. 27 , n. 3 , 2010 , pp. 356-362

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