Byron Brehm-Stecher - Antilisterial effects of gravinol-s grape seed extract at low levels in aqueous media and its potential application as a produce wash.

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      Publication Details (including relevant citation   information):

      J Food Prot. 2010   Feb;73(2):266-73.

      Abstract:

      Grape seed extract (GSE) is a rich source of proanthocyanidins, a   class of natural antioxidants reported to have wide-ranging   bioactivity as anti-inflammatory, anticarcinogenic, and   antimicrobial agents. The ability of GSE to rapidly inactivate   Listeria monocytogenes in vitro and the generally recognized as   safe status of GSE make this extract an attractive candidate for   control of Listeria in or on foods. Previously, GSE has been used   at relatively high concentrations (1%) in complex food matrices   and in combination with other antimicrobials. We sought to   characterize the antilisterial effects of a commercial GSE   preparation (Gravinol-S) alone at much lower concentrations   (0.00015 to 0.125%) in aqueous solution and to test its possible   use as an antimicrobial wash for fresh produce surfaces. Based on   broth microdilution tests, the MICs of GSE against L.   monocytogenes Scott A and Listeria innocua ATCC 33090 were as low   as 50 and 78 mug ml(-1), respectively. GSE was evaluated in 0.85%   saline against live cells of L. innocua via flow cytometry, using   propidium iodide as a probe for membrane integrity. At sub-MICs   and after only 2 min of exposure, treatment with GSE caused rapid   permeabilization and clumping of L. innocua, results that we   confirmed for L. monocytogenes using fluorescence microscopy and   Live/Dead staining. At higher concentrations (0.125%), GSE   reduced viable cell counts for L. monocytogenes by approximately   2 log units within 2 min on tomato surfaces. These results   suggest the potential for GSE as a natural control of Listeria   spp. on low-complexity foods such as tomatoes.

      Address (URL): http://www.ncbi.nlm.nih.gov/pubmed/20132671