Control Of Aflatoxin Production Research Articles

Characteristics of inhibition of Aspergillus flavus growth and degradation of aflatoxin B1 by cell-free fermentation supernatant of Bacillus velezensis 906

Aflatoxin, a harmful secondary metabolite produced by Aspergillus flavus and Aspergillus parasiticus, poses a significant risk to human health and food safety. Therefore, the development of safe and environmentally friendly techniques for controlling A. flavus and its aflatoxin production is imperative. In this study, Bacillus velezensis 906 cell-free fermentation supernatant (CFS) inhibited the germination of A. flavus spores and mycelium growth. Scanning electron microscopy and fluorescence microscopy revealed that CFS altered cell morphology and damaged the cell membrane of A. flavus leading to cell death. Fourier transform infrared spectroscopy indicated changes in the functional groups of A. flavus filaments treated with CFS. The trend in ergosterol content demonstrated that CFS effectively inhibited the normal growth of A. flavus cell membranes. The CFS exhibited remarkable efficacy in degrading aflatoxin B1 (AFB1), achieving a degradation rate of up to 60% after 48 h of interaction. The addition of 0.2 mg/mL Cu2+ or Fe3+ metal ions to CFS significantly increased the degradation rate of AFB1 up to 90%. Furthermore, the analysis indicated that the active components responsible for AFB1 degradation might be heat-resistance and exhibit resistance to protease K. These findings underscore the potential of CFS as a green, safe, and economically viable strategy for controlling aflatoxin production by A. flavus, offering promising prospects for mitigating mold contamination in food and feed applications.

Detection and quantification of aflatoxins in spices stored in different food packaging materials

The current research aims to examine the effect of storage conditions on aflatoxin production in different spices. For this purpose, different samples of spices (Red chilies, Black peppers, and Cumin) were packaged in different packing materials, high-density polyethylene bags, and jute bags and stored in a controlled environment at 25 °C temperature with varying relative humidity conditions (RH: 65%, 75%, 85%) and evaluated for moisture content, total phenolics, Aspergillus count, total fungal count, and aflatoxins. Packaging materials and storage conditions showed a gradual increase in the tested parameters with increased humidity. The mean Aspergillus count for red chillies, cumin, and black pepper was lowest in HDPE (2.20 × 102, 3.00 × 101 and 4.50 × 101, respectively) with 65% moisture content. Aflatoxins were also detected highest (3.33 ppb) in the jute package with 85% moisture content as compared to HDPE (0.9 ppb) for red chilies. Evaluated results proved that spices packed and stored in polyethylene bags retained better quality at 65% relative humidity, where aflatoxin levels were not detected even at 90 days storage period. However, the aflatoxin level was observed lowest (0.13 ppb in cumin) after 120 days of storage. Thus, the utilization of polyethylene packages as compared to jute bags has a better effect on the safety and quality of spices by controlling aflatoxin production during storage.

Effect of Selected Fungicides in the Control of Aflatoxin-producing Fungi in Pre-harvest Maize (Zea mays L) in Anambra State

Contamination of maize by toxigenic fungi is the process that occur yet in the field. Aflatoxin contamination in several foodstuffs has been a recurrent problem. This study is aimed to evaluate the effect of selected fungicides in the control of aflatoxin-producing fungi affecting growth in pre-harvest maize (Zea mays L). Maize seeds treated with organic and synthetic fungicides were sown immediately after land preparation comprising of 13 plots. Five plants each were randomly selected from 13 plots for collecting data for 12 weeks at 2 week interval. Effect of organic and synthetic fungicide in the control of aflatoxin production on the growth parameters of maize showed that maize treated with Azadirachta indica recorded significant growth in the leaf area for all treatments for weeks 8, 10 and 12 while at week 6, maize treated with Cymbopogon citratus showed significant growth in the leaf area at 0.05% for TLg25%, TLg75% and TLg100%. Maize treated with synthetic fungicide (mancozeeb) showed significant growth in the leaf area for weeks 8, 10, 12 in all treatments. Maize treated with Azadirachta indica recorded a significant difference in the plant height for week 4, 10 and 12 in all treatments. For maize treated with Cympobogon citratus, weeks 2 and 8 recorded no significant difference in the plant height but showed a significant growth in the plant height at weeks 4 and 12 (for all treatments) while weeks 6 and 10 recorded significant growth in the plant height for some of the treatments. Maize treated with synthetic fungicide showed significant growth in the plant height for weeks 4, 10 and 12. Fungal isolates identified in this study were: Aspergillus spp. Fusarium spp. and Penicillium spp., with Aspergillus spp. having the highest frequency of occurrence of 4 in treatments TAi100%, TLg75%. The result showed that both organic and synthetic fungicide were effective in the control of aflatoxin-producing fungi on the maize yield but was more effective with the organic fungicide. The use of Azadirachta indica and Cymbopogon citratus is recommended as a means of biofungicides to control aflatoxin-producing fungi in maize.

Inhibition ofAspergillus flavus growth and aflatoxin B1 production by natamycin

Aspergillus flavus causes huge crop losses, reduces crop quality and has adverse effects on human and animal health. A large amount of food contaminated with aflatoxin can greatly increase the risk of liver cancer. Therefore, prevention and control of aflatoxin production have aroused attention of research in various countries. Natamycin extracted fromStreptomyces spp. has been widely used in production practice due to its good specificity and safety. Here, we found that natamycin could significantly inhibit fungal growth, conidia germination, ergosterol and AFB1 production byA. flavus in a dose-dependent manner. Scanning electron microscope analysis indicated that the number of conidia was decreased, the outer wall of conidia was destroyed, and the mycelia were shrivelled and tangled by natamycin. RNA-Seq data indicated that natamycin inhibited fungal growth and conidia development ofA. flavus by significantly down-regulating some genes involved in ergosterol biosynthesis, such asErg13,HMG1 andHMG2. It inhibited conidia germination by significantly down-regulating some genes related to conidia development, such asFluG andVosA. After natamycin exposure, the decreased ratio ofaflS/aflR caused by the down-regulation of all the structural genes, which subsequently resulted in the suppression of AFB1 production. In conclusion, this study served to reveal the inhibitory mechanisms of natamycin on fungal growth and AFB1 biosynthesis inA. flavus and to provide solid evidence for its application in controlling AFB1 contamination.

Control of Aflatoxin Production in Cassava Produced by Dry Fermentation in North Kivu, Democratic Republic of Congo

Traditionally, cassava (Manihot esculenta Crantz) is transformed by fermentation in water (retting) or in the open air (dry fermentation) in the DRC. In the east of the country (North Kivu), dry fermentation is the main technique for processing cassava for its detoxification and conservation. The Congolese farmers ferment the cassava to the open air using a preselected microferment contained in the scrapings of the fermented cassava previously called "MUSIYIRO". These fermentations are spontaneously directed by the microorganisms of the uncontrolled autochthonous flora. Unfortunately, toxinogenic molds are often more active in the fermentation process during which they also produce aflatoxins. This study was undertaken to help prevent the production of aflatoxins in cassava during this process. To do this, we substituted the traditional ferment with a strain of Rhizopus oryzae used as starter (microferment). Six successive replications, in controlled fermentation and uncontrolled fermentation, in a peasant environment (Beni, North Kivu) and fermentation directed by the strain of R. oryzae were carried out. Aflatoxins were then dosed in both groups of cassava flours. The results of the assay revealed an absence of aflatoxins in cassava fermented by scrapings from fermentation led by R. oryzea, while the non-directed fermentation controls were all contaminated with aflatoxins. These results show that it is possible to prevent the production of aflatoxins in cassava during fermentation when an aflatoxin-inhibiting microbial biomass is used which can progressively invade and colonize the fermentation site and thereby control the fermentation activities of cassava.

Effects of Medicinal Plant Extracts and Photosensitization on Aflatoxin Producing Aspergillus flavus (Raper and Fennell).

This study was undertaken with an aim of exploring the effectiveness of medicinal plant extracts in the control of aflatoxin production. Antifungal properties, photosensitization, and phytochemical composition of aqueous and organic extracts of fruits from Solanum aculeastrum, bark from Syzygium cordatum, and leaves from Prunus africana, Ocimum lamiifolium, Lippia kituiensis, and Spinacia oleracea were tested. Spores from four-day-old cultures of previously identified toxigenic fungi, UONV017 and UONV003, were used. Disc diffusion and broth dilution methods were used to test the antifungal activity. The spores were suspended in 2 ml of each extract separately and treated with visible light (420 nm) for varying periods. Organic extracts displayed species and concentration dependent antifungal activity. Solanum aculeastrum had the highest zones of inhibition diameters in both strains: UONV017 (mean = 18.50 ± 0.71 mm) and UONV003 (mean = 11.92 ± 0.94 mm) at 600 mg/ml. Aqueous extracts had no antifungal activity because all diameters were below 8 mm. Solanum aculeastrum had the lowest minimum inhibitory concentration at 25 mg/ml against A. flavus UONV017. All the plant extracts in combination with light reduced the viability of fungal conidia compared with the controls without light, without extracts, and without both extracts and light. Six bioactive compounds were analyzed in the plant extracts. Medicinal plant extracts in this study can control conidia viability and hence with further development can control toxigenic fungal spread.

Stimulato-Inhibitory Response to Cumin Oil in Aflatoxin B1 Production of Aspergillus Species

Background: Aspergillus species produce the highly toxic and carcinogenic metabolite, Aflatoxin B1 (AFB1), on food and agricultural commodities. Some natural products are known to inhibit aflatoxin production. Objectives: With the aim of controlling aflatoxin production, the essential oils of Cuminum cyminum L. from the best known regions of Iran i.e. Alborz Mountain and Kerman region, were obtained by hydrodistillation. Materials and Methods: Antifungal activities of the oils to inhibit growth and aflatoxin productivity of A. flavus PICC-AF39, A. flavus PICC-AF24, and A. parasiticus NRRL-2999 were studied. Minimal inhibitory (MIC) and minimal fungicidal (MFC) concentrations of the oil were determined. Sub-MIC was selected for the measurement of aflatoxins B and G concentration. Samples were analyzed either using a high performance liquid chromatography (HPLC) method with some minor modifications. Aflatoxins (AFs) were determined by reverse-phase HPLC and fluorescence detector with post column derivatization (PCD) involving bromination. Results: A significant reduction in Aflatoxin production was noted which was not due to the inhibitory effect but because of antifungal property of the oil. Interestingly, the oil promoted toxin production for the reasons yet to be investigated. The extent of aflatoxin production was dependent on the concentration of essential oil used. All toxin-producing fungi in this study produced higher amount of aflatoxin at low concentrations of the oil. 400 ppm concentration of C. cyminum L. from Alborz Mountain increased aflatoxin production to over fourfold. Aflatoxin productivity was declined at high concentration of the oil. Conclusions: Antimicrobial and antitoxigenic properties of natural products need a firmly established criterion before they could be offered to application.

Chemical Profile, Antioxidant, Antifungal and Antiaflatoxigenic Activity of Parsley and Ginger Volatile and Non-Volatile Extracts

Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Natural products refer that aromatic components of spices can control the production of aflatoxins. With a view to controlling aflatoxin production, the volatile and nonvolatile extracts from parsley and ginger were obtained by hydrodistillation and ethanol extraction. Antifungal activities of the extracts were studied with special reference to the inhibition of Aspergillus flavus growth and aflatoxin production. Minimal inhibitory (MIC) and minimal fungicidal concentrations of the extracts were determined. Parsley essential oil showed a stronger inhibitory effect than ginger on the growth of A. flavus. On the contrary, ginger ethanolic extract has superior inhibition for aflatoxin production at 20000 ppm (92.93 %). The essential oils of parsley and ginger analyzed by GC-MS) comprised 19.17 % and 8.67 % monoterpenes, 59.74 % and 82.8 % sesquiterpenes, 1.99 % and 3.18 % oxygenated monoterpenes, and 18.98 % and 3.93 % oxygenated sesquiterpenes, respectively and the major volatile compounds in the parsley were myristicin (44%), apiole (16.8%), copaene (13.39%) and β-pinene (6.91%), where as zingibrine (37.65 %), δ-amorphene (19.76%) and α-curcumin (11.32 %) in ginger oil. The antioxidant activity (IC50) of parsley extracts, as compared with that of TBHQ were superior to ginger extracts in DPPH and β-carotene/bleaching assays. It is concluded that both the essential oils could be safely used as preservative materials for some kinds of foods to protect them from toxigenic fungal infections and highlight the potential of this food plants for their possible clinical uses.

Laboratory tests for assessing efficacy of atoxigenic Aspergillus flavus strains as biocontrol agents

Biocontrol by competitive inhibition using atoxigenic Aspergillus flavus strains has been shown to be an effective method for controlling aflatoxin production in peanuts, maize and cottonseed. Selecting biocontrol strains is not straightforward, as it is difficult to assess fitness for the task without expensive field trials. Reconstruction experiments have been generally performed under laboratory conditions to investigate the biological mechanisms underlying the efficacy of atoxigenic strains in preventing aflatoxin production and/or to give a preliminary indication of strain performance when released in the field. The study here described was conducted in order to evaluate the potential of the different atoxigenic A. flavus strains, colonizing the corn fields of the Po Valley, in reducing aflatoxin accumulation when grown in mixed cultures together with atoxigenic strains; additionally, we developed a simple and inexpensive procedure that may be used to scale-up the screening process and to increase knowledge on the mechanisms interfering with mycotoxin production during co-infection.

Chemical Profile, Antioxidant, Antifungal and Antiaflatoxigenic Activity of Parsley and Ginger Volatile and Non-volatile Extracts

Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Natural products refer that aromatic components of spices can control the production of aflatoxins. With a view to controlling aflatoxin production, the volatile and non-volatile extracts from parsley and ginger were obtained by hydrodistillation and ethanol extraction. Antifungal activities of the extracts were studied with special reference to the inhibition of Aspergillus flavus growth and aflatoxin production. Parsley essential oil showed a stronger inhibitory effect than ginger on the growth of A. flavus. On the contrary, ginger ethanolic extract has superior inhibition for aflatoxin production at 20000 ppm (92.93 %). The essential oils of parsley and ginger analyzed by GC-MS) comprised 19.17 % and 8.67 % monoterpenes, 59.74 % and 82.8 % sesquiterpenes, 1.99 % and 3.18 % oxygenated monoterpenes, and 18.98 % and 3.93 % oxygenated sesquiterpenes, respectively and the major volatile compounds in the parsley were myristicin (44 %), apiole (16.8 %), copaene (13.39 %) and ß-pinene (6.91 %), where as zingibrine (37.65 %), ô-amorphene (19.76 %) and Ot-curcumin (11.32 %) in ginger oil. The antioxidant activity (IC50) of parsley extracts, as compared with that of TBHQ were superior to ginger extracts in DPPH and ß-carotene/bleaching assays. It is concluded that both the essential oils could be safely used as preservative materials for some kinds of foods to protect them from toxigenic fungal infections and highlight the potential of this food plants for their possible clinical uses.

Antimycotoxigenic characteristics of Rosmarinus officinalis and Trachyspermum copticum L. essential oils

Aflatoxin B 1 (AFB 1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Natural products may regulate the cellular effects of aflatoxins and evidence suggests that aromatic organic compounds of spices can control the production of aflatoxins. With a view to controlling aflatoxin production, the essential oils from Rosmarinus officinalis and Trachyspermum copticum L. were obtained by hydrodistillation. Antifungal activities of the oils were studied with special reference to the inhibition of Aspergillus parasiticus growth and aflatoxin production. Minimal inhibitory (MIC) and minimal fungicidal (MFC) concentrations of the oils were determined. T. copticum L. oil showed a stronger inhibitory effect than R. officinalis on the growth of A. parasiticus. Aflatoxin production was inhibited at 450 ppm of both oils with that of R. officinalis being stronger inhibitor. The oils were analyzed by GC and GC/MS. The major components of R. officinalis and T. copticum L. oils were Piperitone (23.65%), α-pinene (14.94%), Limonene (14.89%), 1,8-Cineole (7.43%) and Thymol (37.2%), P-Cymene (32.3%), γ-Terpinene (27.3%) respectively. It is concluded that the essential oils could be safely used as preservative materials on some kinds of foods to protect them from toxigenic fungal infections.

Effect of phosphine (ph3) in controlling aflatoxin production in stored groundnut (Arachis hypogea) and wet maize (Zeamais)

The potentials of phosphine in controlling aflatoxin production by Aspergillus flavus on groundnut and wet maize stored in seaied containers under ambient conditions in the laboratory were studied. Groundnut and wet maize inoculated with spore suspensions of A. flavus and exposed to phosphine in sealed containers for toxin production had a very low mold counts and an aflatoxin B1 of less than 5 mg/kg during 6 months storage. The grains remained fresh without loss in quality at the end of storage. Similarly treated groundnut and wet maize stored in air in sealed containers had a very high mold count and aflatoxin B1 contents within 10 and 2 days, respectively. The results of the study will be useful in post-harvest handling of damp grains in the humid zone where the harvesting period of maize coincides with the wet season.

Laboratory evaluation of chemical control of aflatoxin production in unshelled peanuts (Arachis hypogaea L.).

Propionic acid (ammonium salt) at 3000 mg/kg (PA1) and 5000 mg/kg (PA2) of unshelled peanuts (UP); grapefruit seed extract at 5000 mg/kg (GF1) and 10,000 mg/kg (GF2); sodium orthophenylphenate at 2500 mg/kg (SOP1) and 5000 mg/kg (SOP2); thiabendazole 1000 mg/kg (TBZ1) and 5000 mg/kg (TBZ2) were studied in the laboratory, to verify their efficiency in controlling fungal growth and aflatoxin (AF) production on moist UP (16-18% moisture content). Moist UP were put into polyethylene bags with cotton plugs and incubated at 30 +/- 2 degrees C for 28 days. Treatments were considered efficient when the AF content (B1 + G1) remained under 30 micrograms/kg. PA1 treatment was efficient till 14 days of incubation and PA2 during the whole incubation period (28 days). All other treatments were not efficient, showing AF contents from 150 to 108,333 micrograms/kg during the incubation periods. Propionic acid, used as ammonium propionate, at 5000 mg/kg shows promise in controlling aflatoxin production when applied to moist unshelled peanuts.

Effect of gas barrier characteristics of films on aflatoxin production by Aspergillus flavus in peanuts packaged under modified atmosphere packaging (MAP) conditions

The effects of the gas barrier characteristics of three films (ASI, ASII and ASIII) and storage temperature on the growth of, and aflatoxin production by, Aspergillus flavus in peanuts packaged in air and under a modified gas atmosphere of CO 2:N 2 (65:35) were investigated. Mold growth was barely visible in air packaged peanuts using high-medium barrier films (ASI and ASII) and stored at 20°C with more extensive growth occurring in air packaged peanuts stored at 25 and 30°C. Extensive mycelial growth and sporulation occurred in all air packaged peanuts in a low barrier film (ASIII), especially at 30°C. Gas packaging inhibited mold growth in peanuts packaged in a high gas barrier film at 20°C. However, mold growth occurred in gas packaged peanuts packaged in film ASII at higher storage temperatures while extensive mycelial growth was observed in all peanuts packaged in film ASIII irrespective of storage temperature. Levels of aflatoxin greater than the regulatory limit of 20 ng/g were detected in all air packaged peanuts with the highest level of aflatoxin (∼76 ng/g) being detected in peanuts packaged in a high gas barrier film ASI. Aflatoxin production was inhibited in gas packaged peanuts using a high barrier film. However, higher levels of aflatoxin were detected in all gas packaged peanuts in medium-low gas barrier films (ASII and ASIII), particularly at higher storage temperatures. This study has shown that MAP using a CO 2:N 2 (65:35) gas mixture was effective in controlling aflatoxin production by A. flavus in peanuts to levels less than the regulatory limit of 20 ng/g. However, the antimycotic effect of low O 2-high CO 2 atmospheres is dependent on the gas barrier characteristics of the packaging films, especially at higher storage temperatures.

Growth, sclerotia and aflatoxin production by Aspergillus parasiticus: influence of food preservatives

The influence of six food preservatives on control of aflatoxin production by Aspergillus parasiticus was tested in SMKY and defined media at three concentrations, viz., 0.1, 0.5 and 1.0%. Propionic acid completely inhibited the yield of mycelia and sclerotia, and aflatoxin production in culture medium, mycelia and sclerotia of A. parasiticus at all concentrations, whereas citric acid showed inhibition only at 0.5 and 1.0% concentrations. Sodium metabisulphite did not permit mycelial growth and aflatoxin biosynthesis in SMKY liquid medium but allowed production of sclerotia and aflatoxin on solid media, while the rest of the food preservatives had only marginal inhibitory effects.

Effect of some food preservatives on aflatoxin production.

The effect of some food preservatives, such as sorbic (SA) and propionic (PA) acids, on aflatoxin production in synthetic media or in moistened (20%) wheat seeds, was investigated. The preservatives tested, added to synthetic media at sublethal concentrations both at the inoculum and after 5 days of incubation, stimulated aflatoxin production by Aspergillus parasiticus. Sorbic and propionic acids are metabolized by the fungus in vivo and in vitro. Lower concentrations of PA and SA (0.05 to 0.1% w/w) in wheat seeds are ineffective against both fungal growth and aflatoxin production, whilst the combined use of butylated hydroxy toluene (BHT), and PA or SA was more effective in controlling aflatoxin production than their use as single components.

Transformation of Aspergillus parasiticus with a homologous gene (pyrG) involved in pyrimidine biosynthesis

The lack of efficient transformation methods for aflatoxigenic Aspergillus parasiticus has been a major constraint for the study of aflatoxin biosynthesis at the genetic level. A transformation system with efficiencies of 30 to 50 stable transformants per microgram of DNA was developed for A. parasiticus by using the homologous pyrG gene. The pyrG gene from A. parasiticus was isolated by in situ plaque hybridization of a lambda genomic DNA library. Uridine auxotrophs of A. parasiticus ATCC 36537, a mutant blocked in aflatoxin biosynthesis, were isolated by selection on 5-fluoroorotic acid following nitrosoguanidine mutagenesis. Isolates with mutations in the pyrG gene resulting in elimination of orotidine monophosphate (OMP) decarboxylase activity were detected by assaying cell extracts for their ability to convert [14C]OMP to [14C]UMP. Transformation of A. parasiticus pyrG protoplasts with the homologous pyrG gene restored the fungal cells to prototrophy. Enzymatic analysis of cell extracts of transformant clones demonstrated that these extracts had the ability to convert [14C]OMP to [14C]UMP. Southern analysis of DNA purified from transformant clones indicated that both pUC19 vector sequences and pyrG sequences were integrated into the genome. The development of this pyrG transformation system should allow cloning of the aflatoxin-biosynthetic genes, which will be useful in studying the regulation of aflatoxin biosynthesis and may ultimately provide a means for controlling aflatoxin production in the field.

Environmental and nutritional factors controlling aflatoxin production in cassava solid state fermentation

A physiological study of Aspergillus parasiticus on cassava solid state fermentation was performed to evaluate the risks of aflatoxin (AT) contamination of the cassava protein enrichment process with Aspergillus niger. The effects of key environmental (temperature, initial moisture content, aeration rate), nutritional (nitrogen and phosphorous source concentration) and ecological (mixed cultures using A. niger and different amounts of A. parasiticus) factors on aflatoxin production by A. parasiticus in this culture system were evaluated. It was found that A. parasiticus can grow and produce aflatoxins in this system. However, the operation temperature of the protein enrichment process (35°C) drastically reduces potential toxin production. Although N and P concentrations in the medium are partially inhibitory for AT biosynthesis, very high production can be attained anyway. The best toxicological protection was the strain itself ( A. niger no. 10). When these two species grew together in solid state fermentation, aflatoxin production was completely inhibited.

EFFECT OF SODIUM ACETATE ON GROWTH AND AFLATOXIN PRODUCTION BY Aspergillus parasiticus NRRL 2999

ABSTRACTThe effect of sodium acetate and propionate on growth and aflatoxin oroduction by A. Darasiticus NRRL 2999 was studied in AMY medium imodified AM medium + 2% yeast extract) to determine the possible use of this compound as a means of controlling aflatoxin production. At pH 4.5, concentrations of sodium acetate ≥ 1.0g/100 ml completely inhibited growth and prevented aflatoxin production, while levels of 0.6 and 0.8g/100 ml partially inhibited growth and decreased aflatoxin production by 70% and 99%, respectively. Examination of the effect of initial pH on the inhibitory action of sodium acetate indicated that the extent of inhibition was a function of the initial pH. The effect of propionic acid on growth and aflatoxin production was also examined, and this compound was found to be more inhibitory than acetate. The role of sodium acetate and propionic acid as a means of controlling aflatoxin production appears to be promising.

Control of Aflatoxin Production During Fermentation of Wild Rice

The effect of water content of wild rice on aflatoxin production by Aspergillus flavus growing in the rice during fermentation, and influences of processing steps as means to reduce aflatoxin contamination were investigated. Aflatoxin was either not detected or rarely observed during 31 days of storage when rice saturated with water or adjusted to contain 33% water was inoculated with spores of A. flavus and stored at 25 C. Detectable amounts of aflatoxin developed in rice maintained at 20% moisture. Aflatoxin B1 content of contaminated fermented wet wild rice was reduced by parching. Aflatoxin analyses of hulls and kernels from parched rice indicated that most of the aflatoxin B1 remained in the hulls; however, detectable amounts of aflatoxin B1 were present in hulled rice kernels. When wild rice was sterilized with ethylene oxide, saturated with water, stored at 25 C, and inoculated with A. flavus, the mold grew if the rice was mixed daily, but only 10 ppb aflatoxin appeared after 19 days of storage. A. flavus did not grow in similarly treated rice that was not mixed.