The Effects of Drying and Shelling on Aspergillus Flaws Infection and Aflatoxin Production of Maize*

The effects of drying and shelling on Aspergillus fla\-us infection and aflatoxin production of maize stored under laboratory conditions were investigated together with the intactness of grain and change of moisture content during the storage period. Fully matured maize var. Arjuna and CPI-2 were harvested at 90 and 97 days after planting, respectively, after which they were unhusked and divided into 4 pans. The 1st and the 2nd parts were sun dried up to 20^ moisture content (m.c.) and then shelled and re-dried up to 17 and 14% m.c.. respectively. The 3rd part was sun dried up to 17% m.c. and then shelled but not re-dned. The 4th pan was sun dried up to 17% m.c. and then shelled and re-dried up to 14% m.c. The maize was sun dried by spreading either the cobs or the kernels on the paved floor. The nail-down wood and mechanical sheller were used for shelling the maize. After drying and shelling, maize samples were stored in the jars which were covered with muslin cloth for 3 months under laboratory conditions. A. flavus was isolated using dilution method on Aspergillus Flavus and Parasiticus Agar (AFPA). The damaged kernel analysis was carried out at the beginning of storage to obtain the percentage of damaged kernel caused by shelling. The m.c. and aflatoxin were determined using oven and High Performance Liquid Chromatography (HPLC) methods, respectively. The m.c. decreased at 1 month of storage and then it was almost constant at 2 and 3 months of storage. The percentage of damaged kernels of maize var. CPI-2 was higher than those of var. Arjuna. The percentage of damaged kernels of maize shelled at 20% m.c. was higher than that shelled at 17% m.c. The percentage of damaged kernels of maize shelled by mechanical sheller was higher than that shelled by nail-down wood.*Paper presented at the Symposium on Pest Management for Stored Food and Feed, 5 -7 September 1995 Bogor, Indonesia

Control of Aflatoxigenic Aspergillus Flavus in Peanuts Using Nonaflatoxigenic a. Flavus, a. Niger and Trichoderma Harzianum

The effects of nontoxigenic Aspergillus flavus, A. Niger and Trichoderma harzianum inoculated into planting media on toxigenic A. flavus infection and its aflatoxin production in peanut kernels at harvest were investigated together with (1) the moisture content of planting media before peanut planting, at the time of inflorescence, and at harvest, (2) the population of aflatoxigenic and nonaflatoxigenic A. flavus, A. Niger and T. harzianum in peanut planting media before peanut planting, at the time of inflorescence, and at harvest, (3) the moisture content of peanut kernels at harvest, and (4) toxigenic A. flavus invasion in peanut plant parts (roots, stems, petioles, leaves and flowers) at the time of inflorescence. The fungal isolates were inoculated into planting media at the same time with the planting of peanut seeds. Peanut plants were grown under glasshouse conditions. Treated planting media were inoculated with the combined use of (1) toxigenic and nontoxigenic A. flavus, (2) toxigenic A. flavus and A. Niger, and (3) toxigenic A. flavus and T. harzianum. Planting media inoculated only with each fungal isolate and uninoculated planting media were used as controls. Two watering treatments of peanut plants were carried out, i.e. watering until harvest and not watering for 15 days before harvest. The populations of the fungal isolates in the planting media and peanut kernels were determined using dilution method followed by pour plate method; the percentages of toxigenic A. flavus and test fungal colonizations in peanut plant parts were determined using plating method; the moisture content of planting media and peanut kernels were determined using oven method; the aflatoxin content of peanut kernels was determined using Thin Layer Chromatography method. The results indicated that at the time of harvest the decrease in moisture contents of planting media not watered for 15 days before harvest was higher than those watered until harvest. The lowest population of toxigenic A. flavus was in planting media inoculated with the combined use of toxigenic and nontoxigenic A. flavus at the time of inflorescence and at the time of harvest. Toxigenic A. flavus could invade the roots, stems and flowers of peanut plants. The lowest percentage of invasion was on the plant parts which planting media were inoculated with the combined use of toxigenic and nontoxigenic A. flavus. The moisture content of peanut kernels originated from watered plants until harvest were higher than those not watered for 15 days before harvest. The population of toxigenic A. flavus in peanut kernels derived from the plants whose planting media were inoculated with the combined use of toxigenic A. flavus and each test fungi, was lower than those inoculated only with toxigenic A. flavus. It indicated that the test fungi inoculated into planting media could inhibit toxigenic A. flavus infection in peanut kernels. Aflatoxin was only detected in peanut kernels originated from one plant whose planting medium was inoculated only with toxigenic A. flavus and the plant was watered until the time of harvest. Toxigenic A. flavus infection and aflatoxin production were not influenced by planting media which were not watered for 15 days before harvest

The Effects of Milling Degree and Type of Bag on Fungal Infection and Some Chemical Contents of Stored Milled Rice

The effects of milling degree and type of bag on fungal infection of stored milled rice were investigated together with some chemical contents (glucose, amylose, protein and total lipid contents), and changes in moisture content. Rice var. IR 64 with different milling degrees (85, 90, 95 and 100%) packed in jute and polypropylene bags (1 kg of milled rice/bag) were stored under laboratory conditions with temperature between 24.3-27.3 C and relative humidity 52.6-81.9% for 3 months. The initial moisture content (m.c.) of milled rice was ± 14%. Three replications (3 bags) were used for each treatment. Each bag was put individually and was arranged randomly on a wooden pallet. The results showed that in general, the increase of milling degree and duration of storage decreased the m.c. Type of bag did not give significant differences on the m.c. Twenty eight fungal species were isolated from rice with different milling degree and bag type during storage. The predominant species was Aspergillus Candidas. Total fungal population decreased with the increase of milling degree and duration of storage. Bag type did not give significant differences on total fungal population. In general, the increase of milling degree increased glucose content. Glucose content in milled rice packed in jute bag was higher than that in polypropylene bag. Glucose content tended to decrease with the increase of storage duration. The increase of milling degree increased amylose content in milled rice. Amylose content of milled rice packed in jute bag was lower than that in polypropylene bag. The increase of storage duration decreased amylose content in milled rice. In general, protein content decreased with the increase of milling degree and duration of storage. 1 type did not give significant differences on protein content. Total lipid content decreased with the increase of milling degree and duration of storage. Total lipid content of milled rice packed in jute bag was lower than that in polypropylene bag, but based on chemical analysis the difference was not significant. Based on statistical analyses, correlation between the m.c. and total lipid content with total fungal population was positive. There was no correlation between glucose, amylose and protein contents with total fungal population. Rice with high milling degree can be stored safely for long period, but it has low chemical (nutritional) contents

Antagonistic Effect of Four Fungal Isolates to Ganoderma Boninense, the Causal Agent of Basal Stem Rot of Oil Palm

ANTAGONISTIC EFFECT OF FOUR FUNGAL ISOLATES TOGANODERMA BONINENSE, THE CAUSAL AGENT OF BASAL STEM ROT OF OIL PAL

Review on Aflatoxin in Indonesian Food- and Feedstuffs and Their Products

Aflatoxin is a human carcinogen that could contaminate food- and feedstuffs, and hence is a major food quality problem throughout the world. Afiatoxin is produced by certain strains of AspergillusJlavus and //. parasiticus. A number of studies have been carried out in Indonesia on atlatoxin contamination in Indonesian food- and feedstuffs and their products from 1990 up to present. They were maize, maize product, peanuts, soybean and soybean meal, black and white pepper, feed ingredients; chicken and duck feeds. Samples were collected from farmers, traders (middlemen), retailers (markets), supermarkets, exporters; poultry and duck community-based farms; and feed mi l l industries. High levels of aflatoxins were often found in maize, peanuts, chicken feed derived from markets, and duck feed. Low levels of aflatoxins were found in soybean meal and chicken feedstuff. Aflatoxins were not detected in soybean, black and white pepper. Other studies have also been carried out on the effect of carbondioxide (CO2), phosphine, black pepper extract and antagonistic fungi on aflatoxin production of A. flavus in vitro\ and the effect of airtight storage, phosphine, ammonium hydroxide, fermentation process, bag types, and phosphine in combination with different bag types on atlatoxin contents of maize, peanuts and soybean meal. Some of these methods reduced aflatoxin contents significantly

The Possibility of Controlling Sclerotium Rolfsii on Soybean (Glycine Max) Using Trichoderma and Tebuconazole*)

The possibility of controlling S. rolfsii on soybean (Glycine max) var. Rinjani using T. aureoviride and Tebuconazole under field conditions was studied. The experiment was conducted at the experimental plot of SEAMEO BIOTROP. The pathogen was mixed with the soil (2 kg/plot) 4 days before the inoculation of the antagonist (2.25 kg/plot). The measurement of each plot was 2.5 x 6 m2. N, P and K (120 kg/ha) were applied at the same day with the inoculation of the pathogen. Soybean seeds were planted 7 days after the inoculation of the antagonist. The distance between plants and between plots were 20 and 40 cm, respectively. The fungicide at concentration of 100 g/ha (in vitro concentration) and 210 g/ha (field or recommended concentration) were applied using 2 methods, i.e. 1) spraying on the planting hole at the same day as the planting of soybean seeds, and 2) spraying on the soil surrounding the plants 7 days after planting. Soils that were neither inoculated with the antagonist nor the fungicide were used as controls. Three replications (3 plots) were used for each treatment (including the control). The results showed that the inoculation of the antagonist, the concentrations of the fungicide, and time of application gave very significant differences in the percentages of the plants infected by the pathogen and significant differences in seed production; while the interaction between the inoculation of the antagonist and the concentrations of the fungicide, between the concentrations of the fungicide and the time of application, and between the inoculation of the antagonist, the concentrations of the fungicide and the time of application did not give significant differences either in the percentages of the plants infected by the pathogen or seed production. The percentage of plants infected by the pathogen was lower on soil inoculated with the antagonist (31.6%) than on soil not inoculated with the antagonist (52.9%). The percentage of plants infected by the pathogen was lower on soil treated with the fungicide either at in vitro concentration (37.5%) or at field concentration (37.4%) than on the soil not treate

The Occurrence of Insects and Fungi, and Aflatoxin B Contamination of Stored Sorghum in Demak and Wonogiri Regencies, Central Java

The objectives of this study were to collect informations on the method of postharvesthandling of sorghum and to investigate the moisture contents, insects infestation, fungalinfection, and aflatoxin B contents of stored sorghum grains collected from various stagesof the delivery chain in Demak and Wonogiri regencies, Central Java. In Demak regencysorghum cultivation was monoculture, variety cultivated was UPC-S1. In Wonogiri regencysorghum cultivation was intercropping with secondary crop and cassava. Sorghum varietiescultivated were Kawali, Numbu, ZH30, Mandau and Hibrida hybrids. There was a differencebetween the method of postharvest handling of sorghum at farmer and collector levels inDemak andWonogiri regencies. In general the method of postharvest handling of sorghum inDemak regency was more appropriate and more advance compared to that in Wonogiriregency. The moisture contents of sorghum at farmer as well as at collector level in Demakregency (13.0%) and Wonogiri regency (12.9%) were still lower that that of normal (safe)moisture content of sorghum. The number of insect species associated with sorghum invarious distribution level in Demak andWonogiri regencies was 10 and 17 species, respectively.The dominant insects species were and . The number offungal species found in sorghum at various distribution level in Demak andWonogiri regencieswas 23 species, respectively. In general, the dominant fungal species were ,and . In Demak regency aflatoxin B contents of sorghum atfarmer and collector levels were 22.50 and 15.45 ppb, respectively, while in Wonogiri regency2.27 and 10.28 ppb, respectively.insects, fungi, aflatoxin B , stored sorghum, Demak and Wonogiri regencies,Central Jav

Dietary Exposure Assessment for Aflatoxin B From Processed Peanut Products in Municipality of Bogor 1

A research on dietary exposure assessment for aflatoxin B (AFB1) fromprocessed peanutproducts in Municipality of Bogor was carried out. The objectives of this study were todetermine the contents of AFB1 in processed peanut products at retail levels, and to obtaininformation whether there is a risk to public health caused by the consumption of processedpeanut products contaminated by AFB1. Survey of processed peanut product consumptionwas carried out by interviewing each respondent using a questionnaire of weekly processedpeanut product consumption. Sampling of processed peanut products was conducted at thelocations where the respondents obtained processed peanut products. The number of roastedpeanuts with skin pods, flour-coated peanuts and or sauces samples was 33,respectively, while the number of and sauces samples was 18 and 12, respectively.The total number of processed peanut product sampleswas 129.AFB1contentwas determinedusingThin LayerChromatographymethod.Estimation of the dietary exposure assessmentwasdetermined using the actual survey data consisting of AFB1 content, consumption data andbody weight. The highest contaminated sample percentage and mean of AFB1 content wasfound in roasted peanuts with skin pods i.e. 42% of 33 samples and 43.2 μg/kg, respectively,followed by flour-coated peanuts (30% of 33 samples and 34.3 μg/kg), and or(21%of 33 samples and 17.1 μg/kg).Mean of estimated dietary exposure for AFB1 found inchildren was 15.2 ng kg bw day and 95 percentile exposure was 38.9 ng kg bw day , while inadults 9.0 ng kg bw day and 95 percentile exposure was 27.0 ng kg bw day . The excesscancer risk of AFB1 exposure in Bogor fromthis study on children and adults was calculated as193 and 115 cancers/year, respectively-1 -1 th -1 -1-1 -1 th -1 -1pecel gado-gadosiomay sataipecel gado-gado1