FOOD
MICROBIOLOGY
www.elsevier.nl/locate/jnlabr/yfmic
Food Microbiology 21 (2004) 313–318
Effect of essential oils on zearalenone and deoxynivalenol production
by Fusarium graminearum in non-sterilized maize grain
Sonia Mar
!
ın, Andrea Velluti, Antonio J. Ramos, Vicente Sanchis*
Food Technology Department, Lleida University, CeRTA, Rovira Roure 191, 25198 Lleida, Spain
Received 17 March 2003; accepted 7 August 2003
Abstract
The effect of cinnamon, clove, oregano, palmarosa and lemongrass oils on zearalenone (ZEA) and deoxynivalenol (DON)
accumulation by one isolate of Fusarium graminearum in non-sterilized naturally contaminated maize grain at 0.995 and 0.950 a
w
and at 20
C and 30
C was evaluated at a 500 mg kg
À1
level. Efficacy of essential oils was found to be poor, clove essential oil being
that with a broader applicability. In general, competing mycoflora seemed to control to a large extent ZEA and DON accumulation,
and then the effectiveness of essential oils could only be observed under certain environmental conditions, 0.950 a
w
/30
C for ZEA,
and 0.995 a
w
/30
C for DON. Better results might be obtained by applying higher dosages; sensory quality, however, should not be
compromised.
r 2003 Elsevier Ltd. All rights reserved.
Keywords: Mycotoxins; Zearalenone; Deoxynivalenol; Fusarium graminearum; Maize; Essential oils
1. Introduction
Fusarium graminearum Schwabe (sexual state: Gibber-
ella zeae (Schwein.) Petch) causes ear rot of maize corn
(Zea mays L.) in many maize-producing areas of the
world with cool, wet growing seasons (Sutton, 1982).
Mycotoxins usually are present in ears with typical
symptoms of Fusarium ear rot (or Gibberella ear rot)
disease.
Previous studies have illustrated the natural occur-
rence of mycotoxins, specifically deoxynivalenol (DON)
from F. graminearum, in wheat, barley, rye, oats, and
corn (Scott, 1997). Co-occurrence of zearalenone (ZEA)
and several other trichothecenes including DON, 3-
acetyl-DON, 15-acetyl DON, and nivalenol has been
well documented (Tanaka et al., 1990; Kim et al., 1993).
The major effects of ZEA are estrogenic and mostly
affect the urogenital system. It produces a condition
known as hyperestrogenism in pigs and has also been
implicated in some incidents of precocious puberty
changes in children (Kuiper-Goodman et al., 1987). The
trichothecene toxin DON, induces emesis in swine which
is characterized by vomiting, feed refusal, and decreased
weight gain (Vesonder et al., 1981).
Most studies on ZEA and DON focus on their
incidence in different substrates (De Nijs et al., 1996;
Dalcero et al., 1997), identification of the species
responsible for their production (Mubatanhema et al.,
1999) and their location in ears and kernel fractions
(Wetter et al., 1999). For DON, the correlation between
infection symptoms (visual disease severity) and its
presence has been studied (Reid et al., 1996). A few
reports deal with the effect of environmental factors in
these mycotoxins accumulation (Birzele et al., 2000).
Some fungicides have been found to reduce ZEA
accumulation by F. graminearum in synthetic medium
(Hasan, 1993), but few studies report on chemical
treatments for ZEA and DON prevention. Velluti et al.
(unpublished data) found that cinnamon, clove, lemon-
grass, oregano and palmarosa essential oils were able to
inhibit ZEA and DON synthesis under certain environ-
mental conditions in sterile maize inoculated with F.
graminearum. No studies have been carried out, how-
ever, in naturally contaminated maize.
Most studies on antimycotoxigenic effects of essential
oils deal with aflatoxins. A few studies have reported the
effect of essential oils in aflatoxin accumulation in
ARTICLE IN PRESS
*Corresponding author. Tel.: 34-973-702535; fax: 34-973-702596.
E-mail address: vsanchis@tecal.udl.es (V. Sanchis).
0740-0020/$ - see front matter r 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/j.fm.2003.08.002