Journal of Food, Agriculture and Environment




Vol 11, Issue 3&4,2013
Online ISSN: 1459-0263
Print ISSN: 1459-0255


Identification of ochratoxigenic fungi and contextual change on dried raisins (Sultanas)


Author(s):

Levent Şen 1*, Sebahattin Nas 2

Recieved Date: 2013-05-19, Accepted Date: 2013-10-22

Abstract:

Mycotoxins are secondary toxic metabolites synthesized by various filamentous fungi that grow on organic material frequently occurring in agricultural products, including grapes and dried vine fruits. Ochratoxin A (OTA) is a nephrotoxic compound produced mainly by the members of Aspergillus section Nigri and Circumdati in grape and grape derived products. Lower hygienic drying conditions may cause increase in microbiological contamination.Total mold counts were between 3.567 and 6.053 log10 CFU g-1 in unprocessed seedless raisin (Sultana) samples belonging to 20 different vineyards in Denizli region during 2011. Total of 330 strains of filamentous fungi were isolated and 301 isolates belonged to Aspergillus spp. (91.21%), while 29 (8.79%) isolates belonged to other genus such as PenicilliumAlternaria, Cladosporium, Mucor, Ulocladium and Stachybotrys spp. Black aspergilli constituted 91.03% of the Aspergillus strains isolated, namely A. niger (77.58%) and A. aculeatus (5.98%). All Aspergillus isolates were tested for the ability to produce OTA. A. nigerA. aculeatus and A. ochraceus had highest OTA production ability with maximum production of 441.830±100.554, 975.460±9.294 and 10.450±1.914 ng g-1 50% grape juice extract (GJ50) agar, respectively. However, OTA was also produced by other Aspergillus isolates at lower levels compared to A. niger and A. ochraceus isolates in vitro. In a total of 20 samples, OTA was not detected in 13 samples (65%), OTA levels were 0.0-0.16 µg kg-1 (LOQ) in 1 sample (5%), 0.05-1.0 µg kg-1 in 5 samples (25%) and 1.0-2.0 µg kg-1 in 1 sample (5%). None of the 20 samples (100%) contained OTA exceeding current the EC limit (10 µg kg-1) set for dried vine fruits.

Keywords:

Ochratoxigenic fungi, OTA, Sultana, Aspergillus, HPLC, A. niger, A. ochraceus, A. aculeatus, dried vine fruits, filamentous fungi


Journal: Journal of Food, Agriculture and Environment
Year: 2013
Volume: 11
Issue: 3&4
Category: Food and Health
Pages: 155-161


View full PDF
Information:

Note to users

The requested document is freely available only to subscribers/registered users with an online subscription to the Journal of Food, Agriculture & Environment. If you have set up a personal subscription to this title please enter your user name and password. All abstracts are available for free.

Article purchasing

If you like to purchase this specific document such as article, review or this journal issue, contact us. Specify the title of the article or review, issue, number, volume and date of the publication. Software and compilation, Science & Technology, all rights reserved. Your use of this website details or service is governed by terms of use. Authors are invited to check from time to time news or information.


Purchase this Article:   20 Purchase PDF Order Reprints for 15

Share this article :