Screening of antifungal and antimycotoxigenic activity of plant phenolic extracts

Transcription

1 World Mycotoxin Journl, My 2008; 1(2): Wgeningen g Acdemic P u l i s h e r s Screening of ntifungl nd ntimycotoxigenic ctivity of plnt phenolic extrcts M. dos Sntos Oliveir nd E. Bdile Furlong Fundção Universidde Federl do Rio Grnde (FURG), Deprtmento de Químic Lortório de Micotoxins, Ru Eng Alfredo Huch 475, CEP Rio Grnde/RS, Brzil; dqmef@furg.r Received: 21 Novemer 2007 / Accepted: 9 Ferury Wgeningen Acdemic Pulishers Astrct The ntifungl nd ntimycotoxigenic ctivities of extrcts from edile plnts were tested y the gr dilution method using the growth dimeter of Aspergillus flvus s response nd the determintion of fltoxins B 1 nd B 2 in the culture medium. On the 7 th incution dy, the gretest fungl inhiitions were reched y the extrcts from potto peel; rice nd whet; lemon peel nd pulp; eggplnt peel; ornge peel nd pulp; nd pple pulp. After the 14-dy incution, the extrcts from nn (30 µg phenol/ml gr), eggplnt (30 µg phenol/ml gr), nd potto (50 nd 67 µg phenol/ml gr) pulp reduced the production of fltoxin B 1 y 3.2%/µg phenol/ml gr, 2.9%/µg phenol/ml gr, 1.8%/µg phenol/ml gr nd 0.85%/µg phenol/ml gr, respectively, in reltion to the control. The extrcts from the other vegetles fully inhiited the synthesis of the mycotoxin. These results point to the studied plnts nd their residues s potentil sources of phenolic compounds tht my hve n inhiitory effect on fungl development nd the production of mycotoxins in food. Keywords: phenolic compound, Aspergillus flvus, nturl ntifungl 1. Introduction In food production it is lwys necessry to seek pproprite strtegies for ensuring product stility during their shelf life nd their microiologicl sfety, prticulrly in regrd to fungl contmintion (Brul nd Coote, 1999). Food contmintion y fungi leds to chnges in chemicl composition, structure nd ppernce, thus representing economic loss nd/or wste of rw mteril nd food. In ddition, the fungi re responsile for helth prolems in oth humns nd nimls, if they ingest food contminted y mycotoxins produced y toxigenic species in stressful conditions (Tniwki nd Silv, 2001; Pster et l., 1999). Mycotoxins re secondry metolites of certin strins of toxigenic fungi tht hve een shown to e toxigenic, crcinogenic, mutgenic, neurotoxic, nd tertogenic to different species of nimls. These mycotoxin-producing fungi re widely distriuted in nture nd cn grow in wide rnge of environmentl conditions. Their occurrence in food hs een cited in different countries, including Brzil (Bittencourt et l., 2005; Grd et l., 2004; Nunes et l., 2003; Aycicek et l., 2005; Adulkdr et l., 2004). The mycotoxigenic fungi involved in the humn food chin elong minly to gener Aspergillus, Penicillium, nd Fusrium (Sweeney nd Doson, 1998). The fltoxins, of which five re of concern s nturl contminnts in food (fltoxin B 1, B 2, G 1, G 2 nd M 1 ), re secondry metolites from Aspergillus flvus nd A. prsiticus. Afltoxins hve een detected in foods, feed nd griculturl commodities, in different concentrtions. Their toxic effects my mnifest chroniclly (cncer) or cutely (dirrhoe, vomiting, liver disorders) (Sweeney nd Doson, 1998; Moss, 2002). Strtegies for the prevention of mycotoxigenic fungus growth nd the further production of mycotoxins in griculturl produce nd food re the use of fungicide nd chemicl preservtives or het tretment to inctivte spores (Yoshizw, 2001). The resistnce of fungi to ISSN print, ISSN online 139

2 M. dos Sntos Oliveir nd E. Bdile Furlong chemicl preservtives nd legl limittions ensure n incresing demnd for nturlly preserved products. The serch for nturl sources of ntifungl dditives tht re sfe nd efficient to e used in food hs shown tht extrcts nd essentil oils from spices, hers, nd other plnts crry ntifungl ctivity (Solimn nd Bde, 2002; Jugll et l., 2002; Fn nd Chen, 1999). Some compounds hve een cited s eing cple of inhiiting toxigenic species growth, s well s mycotoxin production (Sánchez et l., 2004; Gowd et l., 2004; Mrín et l., 2004). Evidence suggests tht phenolic compounds nturlly found in plnts, hers, fruit, cerels, nd other vegetles, s well s their essentil oils, crry ntifungl ctivity, nd my control mycotoxin production (Rsooli nd Ayneh, 2004; Bkn et l., 2003). The results my e wy to recover wste or mteril rejected from domestic or industril routine processes. Severl phenolic structures, such s crnosol nd eugenol, re found in hers nd spices; flvonoids, s well s chlorogenic, cfeic, ferulic, nd cinnmic cids re found in fruit (Rords et l., 1999). Fungl inhiition hs een reported y phenolic compounds such s eugenol over Penicillium species (Venturini et l., 2002; Vásquez et l., 2001), s well s ntifungl ctivity y phenolic compounds found in ornge (Del Río et l., 1998), pepper essentil oil (Ejechi et l., 1999), olive trees (Del Río et l., 2003), nd other edile or medicinl plnts (Ruh et l., 2000). Such considertions hve guided the ojective of the present study, which ws to investigte the ntifungl nd ntimycotoxigenic ctivity of phenolic extrcts from edile plnt which hs een used in dily diets in mny regions of the world. 2. Mteril nd methods Plnt mteril The plnts studied included ornge (Citrus sinensis, Oseck), lemon (Citrus limon), pple (Mlus domestic Borkh), nn (Mus spp.), rose potto (Solnum tuerosum L.), eggplnt (Sonlum melongin, L.), processed rice (Oryz stiv), nd whole whet (Triticum estivum), purchsed in mrket in the South of Brzil. Fruit nd tuercle peel were seprted from their edile portions, nd then cut into 5 mm cues. Cerel grins were milled using knife-mill, down to 0.42 mm grin size. Totl phenolic ssy Phenol compounds were cold-extrcted with methyl lcohol t 1:5 dry mss:solvent rtio s descried y Bdile-Furlong et l. (2003), then quntified using the spectrophotometric method with Folin-Cioclteu s regent nd tyrosine stndrd curve rnging etween 0 nd 5 µg/ml. The extrcts were concentrted under vcuum for complete removl of solvents. The solvent-free extrcts were used for the present study. Antifungl ctivity test The toxigenic filmentous fungus used in the present study ws Aspergillus flvus, supplied y Lortório de Microiologi t FURG s Chemistry Deprtment, nd kept in Potto Dextrose Agr (PDA) t 4 C. The inoculum ws prepred y growing the fungi on PDA t 30 C for 10 dys. Spores were hrvested y wshing the gr surfce with sterile solution contining 0.2% Pure Agr in Tween 80. Spore counts in the resulting suspensions were determined y microscopy with Neuuer chmer. Antifungl ctivity ws determined y gr dilution method. The test plnt extrct ws dded to PDA Agr in two different volumes, completing two different levels of totl phenol t growth medium, clled level 1 nd level 2. In the control, the sme mount of sterile wter ws dded. Using micropipette, n inoculum of 5 µl of the spore suspensions (10 7 spores/ml) ws dded to the centre of Petri dish. The cultures were incuted t 30 C for 7 dys nd the temperture ws then reduced to 21 C for 7 dys. The rdil growth of myceli ws mesured on the 3 rd, 5 th, 7 th, 10 th, nd 14 th dy of incution for the experiments, conducted s triplictes (Nguefck et l., 2004). After 14 dys, dishes were frozen (-10 C) for further determintion of mycotoxins in the growth medium. Evlution of fltoxins B 1 nd B 2 production Mycotoxins were extrcted from the culture medi with n cetonitrile-wter (3:1) solution while stirring, followed y hexne-sed prtition. Acetonitrile ws seprted from the wter y ddition of sodium chloride, followed y vcuum-evportion t 50 C. The residue ws resuspended with methnol:chloroform 1:9 (v/v), nd centrifuged. Three 10 ml liquots were seprted in n mer glss. They were evported in wter-th under nitrogen current nd stored t -10 C (Tnk et l., 2001). The evported extrcts were pplied to 0.25 mm G60 silic gel chromtosheets for screening nd quntifiction of fltoxins B 1 nd B 2 under UV light (Sores nd Rodriguez- Amy, 1989). Sttisticl nlysis Anlysis of vrince (ANOVA) ws performed on ll dt using the Sttistic Softwre version 5.1. The men vlues of development dimeters were compred y the lest significnt difference (LSD) test t 5% level of confidence. 140 World Mycotoxin Journl 1 (2)

3 Screening of ntifungl nd ntimycotoxigenic ctivity of plnt phenolic extrcts 3. Results nd discussion Medicinl hers, spices (oregno, clove, cinnmon, pepper), nd other edile or non-edile plnts re usully studied s their ntifungl vegetle compounds. Some reserchers hve shown tht extrcts nd essentil oils from grlic nd onions were le to inhiit the development of Aspergillus, Fusrium, nd Penicillium species (Yin nd Tso, 1999; Benkeli, 2004). However, the fruits lemon, ornge, nn, eggplnt, pple; the tuercle potto; nd the grins rice nd whet, which re commonly found in humn diets round the world, hve not een thoroughly studied regrding this ility. In the present study, they were evluted on the mounts of totl phenolic in their edile prt, or pulp, nd peels (Tle 1). The use of such food in distinct regions of the country without n effective use for their residues prompted the interest of the reserch in these vegetles. The totl phenolic compounds content in the edile portion of the vegetle tissues studied rnged from 40 µg phenol/g (dry se) in rice to 4,500 µg phenol/g (dry se) in ornge pulp. The phenolic content in peels rnged from 990 µg phenol/g (dry se) in potto peel to 5,500 µg phenol/g (dry se) in lemon peel. The totl phenolic content in lemon, pple, nn, eggplnt nd potto peels ws higher thn in their respective pulps. The opposite ehviour ws found in ornge peel. Phenolic extrct effect on the growth of Aspergillus flvus The effect of the extrcts ws evluted y mesurements of the growth dimeter of the colonies. Every tested plnt extrct provided inhiition to the growth of A. flvus in oth concentrtions used. An upwrd liner trend ws found for the reltionship etween the concentrtion nd the inhiiting effect for the sme extrct. Tle 2 shows the ssessment results of the Aspergillus flvus growth dimeter in the presence of phenolic extrcts from vegetle peels (lemon, ornge, pple, nn, eggplnt, nd potto) on the 3 rd, 5 th, 7 th, 10 th nd 14 th dy of inocultion. On the 7 th incution dy, colony dimeters mesured from 0 cm for mediums contining potto peel extrct (38 µg phenol/ml gr) to 5.9 cm for mediums contining nn peel extrct (44 µg phenol/ml gr); on the 14 th dy, such mesures were from 0 cm to 6.7 cm for the sme extrcts. The percentge of inhiition y the extrcts ws estimted relting the growth dimeter of the colony developed in the medium with the extrcts nd sence of them. The potto peel extrcts tht presented lower phenolic compound concentrtion nd the colony dimeter estimtion showed 3%/µg phenol/ml gr nd 2.5%/µg phenol/ml gr inhiition. Such profile ws mintined until the 14 th incution dy for the higher phenolic concentrtion level (40µg phenol/ml gr). This high inhiition effect did not tke plce with the other phenolic extrct from peels with higher phenol rtes, like lemon, ornge nd pple. The results indicte tht the type of phenolic structure is more importnt thn the concentrtion. It is known tht some fungi re le to dpt in the presence of some clssic ntifungl compounds, ut this is not oserved in the cse of phenolic extrcts from potto peel. Hydroxyl groups ssigned to the phenolic compounds my form hydrogen ridge onds with ctive enzymes, resulting in their dectivtion nd consequent effect on the development of the fungl iomss nd the production of mycotoxins (Jugll et l., 2002). The men comprison y lest significnt differences conducted for ech dy of growth dimeter mesurements showed tht on the 3 rd nd 5 th dys of incution, the colony Tle 1. Totl phenol content in vegetle portions. Edile portion Totl phenolic compounds µg/g (dry se) Residue Totl phenolic compounds µg/g (dry se) lemon pulp 2,700±57 lemon peel 5,500±160 ornge pulp 4,500±52 ornge peel 4,200±37 pple pulp 1,000±2.6 pple peel 4,700±140 nn pulp 310±8.5 nn peel 1,010±25 eggplnt pulp 390±5.8 eggplnt peel 2,200±96 potto pulp 410±14 potto peel 990±38 rice 40±1.1 whet 290±9.5 Men±Stndrd devition. World Mycotoxin Journl 1 (2) 141

4 M. dos Sntos Oliveir nd E. Bdile Furlong Tle 2. Men growth dimeters of Aspergillus flvus in the presence of vegetle peel extrcts. Peel extrcts Totl phenol µg/ml gr Colony dimeter (cm) 3 rd dy 5 th dy 7 th dy 10 th dy 14 th dy nn ± ± ± ± ±0.4 nn ± ± ± ± ±0.5 lemon ± ± ± ± ±0.3 lemon ±0 0.4± ± ±0.02 ornge ± ± ± ± ±0.1 ornge ± ± ± ± ±0.5 pple ± ± ± ± ±0.3 pple ± ± ± ± ±0.3 eggplnt ±0 1.3± ± ± ±0.5 eggplnt ± ± ± ±0.7 potto ± ± ± ±0.9 potto control - 4.6± ± ± ± ±0.3 dimeters in the presence of extrcts were significntly smller (74%) reltive to the control, confirming the reduction in A. flvus growth rtes. On the 7 th incution dy, only when nn peel extrct (44 µg phenol/ml gr) ws used, it ws found tht fungus growth ws proximte to the control. From the 10 th incution dy on, nn peel extrcts (44 nd 58 µg phenol/ml gr) did not provide ny inhiition, nd the colony dimeters did not present significnt difference reltive to controls. Such ehviour my hve een determined y the type nd concentrtion of the phenolic compounds present in the extrct, which ws not enough to inhiit the initil mount of spores present in the growth medium. It is reported in literture tht concentrtions etween 3,500 nd 5,000 µg phenolic cids/ml growth medium, extrcted from pepper, re the minimum concentrtions required to fully inhiit fungi Rhyzopus stolonifer, A. niger, nd Fusrium spp. fter 48 hours (Ejechi et l., 1999). Figure 1 illustrtes the inhiitory effects of vegetle peel extrcts, dded in two distinct levels, upon the development of A. flvus with 7 dys of incution. The highest inhiition on the 7 th incution dy ws found in the medium contining potto peel extrcts (level 2), with 100% inhiition, followed y lemon peel extrcts (level 2) with 96%, eggplnt peel (level 2) with 90%, nd potto peel extrct (level 1) with 88%. On the 14 th incution dy (Figure 2), the sme performnce sequence ws mintined. The extrcts presented respectively 100%, 91%, 79%, nd 71% of fungl growth inhiition. Vrince nlysis indicted tht there ws significnt difference, with 95% confidence, mong growth dimeter mens in the presence of the distinct plnt extrcts. Figures 1 nd 2 show tht the gretest inhiition occurred when extrcts with the highest phenolic rtes were used. The LSD test indicted tht on the 7 th incution dy, there ws significnt difference etween inhiition occurring for the lower nd higher phenol rtios upon colony dimeter, with the exception of potto peel extrct. At 14 dys of incution, there ws no significnt difference etween the inhiition cused y the higher phenolic compounds concentrtion nd the lower concentrtion of nn nd pple peel extrcts. Tle 3 shows growth dimeter results for A. flvus inoculted in the presence of phenolic compounds extrcted from vegetle pulps on the 3 rd, 5 th, 7 th, 10 th, nd 14 th dy of incution. On the 7 th incution dy, colony dimeters rnged etween 0 cm for rice (6 µg phenol/ml gr) nd whet (9 µg phenol/ml gr) extrct mediums, nd 4.2 cm for ornge pulp extrcts (110 µg phenol/ml gr). On the 14 th dy, these scores rnged from 0 cm to 6.4 cm for mediums contining the sme extrcts. The inhiitory power of rice nd whet extrcts stood out, considering tht they presented the lowest phenol rtes. The vrince nlysis showed significnt difference (95%) etween growth dimeters in the presence of pulps. The LSD test indicted tht on the 3 rd, 5 th, nd 7 th dys of incution, extrct inhiition ws significnt reltive to the control. On the 10 th nd 14 th incution dys, only the ornge pulp extrct dded to the lower phenol level did not mintin inhiition, nd colony dimeters did not present significnt differences reltive to the control. In generl, pulp extrct lso provided inhiition of the development rte of A. flvus, keeping its growth dimeter significntly smller thn the control test until the 14 th 142 World Mycotoxin Journl 1 (2)

5 Screening of ntifungl nd ntimycotoxigenic ctivity of plnt phenolic extrcts Inhiition (%) nn lemon ornge pple eggplnt potto Level 1 Level 2 Inhiition (%) nn lemon ornge pple eggplnt potto Level 1 Level 2 Figure 1. Inhiitory effect of vegetle peel extrcts upon the growth of Aspergillus flvus during 7 dys of incution. Level 1: Lower phenolic extrct level from ech vegetle dded to the growth medium; Level 2: Higher phenolic extrct level from ech vegetle dded to the growth medium.,: The sme letters in the extrct indictes tht there re no differences etween the inhiition exerted y the different phenolic concentrtions. Figure 2. Inhiitory effect of vegetle peel extrcts upon the growth of Aspergillus flvus fter 14 dys of incution. Level 1: Lower phenolic extrct level from ech vegetle dded to the growth medium; Level 2: Higher phenolic extrct.,: The sme letters in the extrct indictes tht there re no differences etween the inhiition exerted y the different phenolic concentrtions. Tle 3. Rdil growth of Aspergillus flvus in the presence of vegetle pulp extrcts. Pulp extrcts Totl phenol µg/ml gr Colony dimeter (cm) 3 rd dy 5 th dy 7 th dy 10 th dy 14 th dy nn ± ± ± ± ±1.4 nn ± ± ± ± ±0.7 lemon ± ± ± ± ±0.4 lemon ± ± ± ± ±0.2 ornge ± ± ± ± ±0.6 ornge ± ± ± ± ±0.5 pple ± ± ± ± ±1.0 pple ± ± ± ± ±0.6 eggplnt ± ± ± ± ±0.8 eggplnt ± ± ± ± ±1.0 potto ± ± ± ± ±0.4 potto ± ± ± ± ±0.5 rice ± ± ± ±0.07 rice whet ±0 0.5±0 1.0± ±0.07 whet ± ±0.03 control 4.6± ± ± ± ±0.3 dy of incution, except for the ornge pulp. Figures 3 nd 4 present fungl inhiition effects of phenol extrcts contined in vegetle pulp upon the development of A. flvus on the 7 th nd 14 th dys of incution, respectively. On the 7 th incution dy, the gretest inhiition occurred in the presence of rice, whet nd pple pulp extrcts. After 14 dys of incution (Figure 4), the gretest inhiition ws lso seen in the presence of rice nd whet extrcts. The LSD test (confidence level 95%) showed tht there ws no significnt difference etween the lower nd higher phenol levels in nn, eggplnt, potto, rice, nd whet pulp extrcts dded to the growth medium. Effects presented y peel extrcts which cused the gretest inhiitions such s lemon, potto, eggplnt, nd ornge nd the est pulp extrcts, such s rice, whet, pple, lemon nd World Mycotoxin Journl 1 (2) 143

6 M. dos Sntos Oliveir nd E. Bdile Furlong Inhiition (%) Inhiition (%) nn lemon ornge pple eggplntpotto rice whet Level 1 Level 2 0 nn lemon ornge pple eggplnt potto rice whet Level 1 Level 2 Figure 3. Effect of extrcts from vegetle tissue pulp upon the growth of Aspergillus flvus during 7 dys of incution. Level 1: Lower phenolic extrct level from ech vegetle dded to the growth medium; Level 2: Higher phenolic extrct.,: The sme letters in the extrct indictes tht there re no differences etween the inhiition exerted y the different phenolic concentrtions. Figure 4. Effect of extrcts from vegetle tissue pulp upon the growth of Aspergillus flvus fter 14 dys of incution. Level 1: Lower phenolic extrct level from ech vegetle dded to the growth medium; Level 2: Higher phenolic extrct.,: The sme letters in the extrct indictes tht there re no differences etween the inhiition exerted y the different phenolic concentrtions. ornge, were suject to vrince nlysis (95%), resulting in significnt difference etween inhiitions cused y such extrcts. It is worth emphsizing tht, fter 7 dys of incution, the gretest fungl inhiition vried from 100% when potto, rice nd whet shells were used with the higher phenolic level, to 64%, using ornge pulp extrct with the higher phenolic level (170 µg phenol/ml gr). After 14 dys, the gretest inhiitions rnged from 100% to 66%. Such vegetle tissues were the est of the ones studied s potentil sources of phenolic compounds, nd could e employed s ntifungl dditives. Fungl inhiition ws highest with the use of rice, whet, potto peel, lemon nd ornge peel nd pulp, eggplnt peel, nd pple pulp. Phenolic extrct effect on the production of fltoxin B 1 nd B 2 y Aspergillus flvus. The most importnt mycotoxins produced y A. flvus re fltoxins B 1 nd B 2, formed y out 40% of the isolted fungi (Tniwki nd Silv, 2001). Tle 4 shows the results of determintions of fltoxins B 1 nd B 2 produced y A. flvus in Potto Dextrose Agr medium in the presence nd sence of phenolic extrcts from the vegetles. The inhiition rte ws clculted considering the sence of production mycotoxin s 100% inhiition. The method y Tnk (2001) nd Sores nd Rodriguez- Amy (1989), dpted t FURG s Lortório de Micotoxins for determintion of mycotoxins ws dpted ecuse it is fst, economic nd hs good performnce to evlute mycotoxin production in the culture medium. The method hs detection limit of 2 µg fl/kg gr oth for fltoxin B 1 nd B 2. The recoveries for fltoxin B 1 nd B 2 re 96.5% nd 91.5% respectively t concentrtion rnge of 2 to 20 µg fl/kg gr with vrition coefficient of 8% for oth mycotoxins. An inhiitory effect upon the production of fltoxin B 1 nd B 2 y A. flvus ws seen in the presence of every extrct t oth studied concentrtions. It is interesting to note tht the fltoxin B 1 nd B 2 production inhiition ws reltively higher thn the inhiition of A. flvus development, when developed in the presence of extrcts from ornge, lemon, pple, rice, whet pulp nd peel, nd nn nd eggplnt peel. Extrcts from vegetle peels nd 62.5% of pulp extrcts fully inhiited the production of fltoxin B 1 nd B 2 ; Tle 4. Afltoxin B 1 nd B 2 production y Aspergillus flvus in the presence of phenolic compounds from vegetle extrcts. Extrcts present of gr Quntifiction (µg/kg gr) fltoxin B 1 fltoxin B 2 control 1,600±140 (0) nd nn peel (44µg phenol/ml gr) nd nd ornge peel (250µg phenol/ml gr) nd nd nn pulp (30µg phenol/ml gr) 75±7.1 (95) <100±0 eggplnt pulp (30µg phenol/ml gr) 195±7.1 (87) nd potto pulp (50µg phenol/ml gr) <100±2.1 (94) <140±7.1 potto pulp (67µg phenol/ml gr) 670±120 (57) 850±200 nd = not detected (detection limit 2 µg/kg gr). Percentge inhiition etween rckets. 144 World Mycotoxin Journl 1 (2)

7 Screening of ntifungl nd ntimycotoxigenic ctivity of plnt phenolic extrcts wheres extrcts from vegetle peels on the 14 th incution dy presented fungl inhiition rnging from 12% in the presence of nn peel extrct to 100%, when potto peel extrct ws used. During the sme period, pulp extrcts presented % inhiition of fungl colony development. When used, nn pulp (30 µg phenol/ml gr), eggplnt pulp (30 µg phenol/ml gr), nd potto pulp (50 nd 67 µg phenol/ml gr) extrcts inhiited respectively 3.2%/µg phenol/ml gr, 2,9%/µg phenol/ml gr, 1.88%/µg phenol/ ml gr nd 0.85%/µg phenol/ml gr of the fltoxin B 1 production (Tle 4), while fungl inhiition ws 0.80%/µg phenol/ml gr, 1.1%/µg phenol/ml gr, 0.66%/µg phenol/ ml gr, nd 0.58%/µg phenol/ml gr for the sme extrcts on the 14 th dy of incution. Such phenolic extrcts my ct y inhiiting oxidtive stress, which is prerequisite for the production of fltoxins, leding to n increse in the lipidic peroxidtion nd the genertion of free rdicls (Jyshree nd Surmnym, 2000). Similr results were found y Selvi et l. (2003), who inoculted Aspergillus flvus in the presence of extrct of Grcini indic, plnt rich in flvonoids nd phenolic cids. The uthors otined 40-60% inhiition of the production of fltoxin B1 nd 10-20% inhiition of fungl growth. It is worth emphsizing tht in the presence of nn pulp (30 µg phenol/ml gr) nd potto pulp (50 nd 67 µg phenol/ml gr) extrcts, A. flvus lso produced fltoxin B 2, which ws not found for the control. Such secondry production my e defence response of the fungus when in the presence of component of those extrcts. The results indicted tht the ntifungl nd ntimycotoxigenic ctivities of vegetle extrcts were relted to the type of phenolic compounds found in the system, fct which hs een reported y other studies. These possiilities re eing studied in our lortory. Bkn et l. (2003) studied the effect of nturl sustrtes in three frctions of corn, whole grins, degerminted grin, nd whet germen upon the production of thrichothecenes y Fusrium grminerum. They lso found tht the production of mycotoxins ws lower or undetectle in the whet germen, frction which presented the highest concentrtion of ρ-coumric nd ferulic cids. 4. Conclusions Every extrct presented ntifungl ctivity on A. flvus. Full inhiition fter 7 dys of incution ws reched y potto peel (38 µg phenol/ml gr), rice (6 µg phenol/ml gr), nd whet (9 µg phenol/ml gr) extrcts. By 14 dys of incution, full inhiition ws found for potto peel (38 µg phenol/ml gr) nd rice (6 µg phenol/ml gr) extrcts. Vegetle peel extrcts nd some pulp extrcts (62.5% of then) inhiited fltoxin production t 100%. Bnn pulp (30 µg phenol/ml gr), eggplnt pulp (30 µg phenol/ml gr), nd potto pulp (50 nd 67 µg phenol/ml gr) extrcts inhiited the production of fltoxin B 1 t 3.2%/µg phenol/ml gr, 2.9%/µg phenol/ml gr, 1.88%/µg phenol/ ml gr nd 0.85%/µg phenol/ml gr, respectively. References Adulkdr, A.H.W., Al-Ali, A.A., Al-Kildi, A.M. nd Al-Jedh, J., Mycotoxins in food products ville in Qtr. Food Control 15: Assocition of Officil Anlyticl Chemists (AOAC), Officil Methods of nlysis Interntionl, 17 th, CD-ROM, Willim Horwitz. Aycicek, H., Aksoy, A. nd Sygi, S., Determintion of fltoxin levels in some diry nd food products which consumed in Ankr, Turkey. Food Control 16: Bdile-Furlong, E., Coll, E., Bortolto, D.S., Bisch, A.L.M. nd Souz-Sores, L.A., Avlição do potencil de compostos fenólicos em tecidos vegetis. 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