New Horizon of Mycotoxicology for Assuring Food Safety (Proceedings of ISMYCO Kagawa'03) Edited by Takumi Yoshizawa C2004 Japanese Association of Mycotoxicology 167 Mycotoxin contamination of food and feeds in the Philippines Rosario H. ARIM Food and Nutrition Research Institute, Department of Science and Technology (General Santos Avenue, Bicutan, Taguig, Metro Manila 1631, Philippines) Summary Mycotoxins are fungal metabolites which cause adverse effects in humans and animals when contaminated foods are ingested. In the Philippines, the most studied mycotoxin is the aflatoxin. There is very limited data on other mycotoxins such as fumonisins, ochratoxin, zearalenone, T-2 toxin and deoxynivalenol. In the country, problems on the export commodity copra meal is one of the major concerns due to its high aflatoxin levels which cause rejection of the oil mill by-product by importing countries, particularly in the European Union. National problem involved the local corn produce which shows aflatoxin levels beyond the 20 Đg/kg tolerance limit. Previous studies showed that corn and peanuts are the most susceptible agricultural commodities that contain toxic levels of aflatoxin. Key words : mycotoxin contamination, aflatoxin, food, feeds Introduction Mycotoxins, particularly aflatoxins, are commonly found in locally produced agricultural crops such as corn, peanuts, coconuts and cassava and their food and feed products. Environmental conditions in the Philippines, i.e. high temperature and high relative humidity favor the growth of aflatoxin-producing fungi, Aspergillus flavus and A. parasiticus in agricultural crops, as well as, the growth of other mycotoxigenic fungi which produce other mycotoxins, aside from aflatoxins. Furthermore, the rainy weather normally coincides with the peak harvest months of staple cereals which results in high grain moisture retention and handling problems, thus promoting accelerated fungal growth and rapid formation and build-up of aflatoxins. Mold infection of, and toxin production in, products such as grains, seeds and nuts are invariably heterogeneously distributed when stored in bulk. In the case of stored grains that are not sufficiently aerated or ventilated, molds start to develop, under conducive environmental conditions, in pockets of moisture accumulation resulting from
168 differences in temperature and relative humidity. Occurrence Aflatoxins B1, B2, G1 and G2 are the most studied and widely known mycotoxins. The high-risk commodities for aflatoxins include cereals such as corn and parboiled rice, seeds such as peanuts and cottonseed, and certain tree nuts such as coconut, and dried fruits. Aflatoxin contamination may occur at any stage of crop production and marketing. Although the fungus A. flavus has been traditionally considered to be a storage mold, it has also been found to occur during pre-harvest conditions. Aflatoxins can be found in not only obviously moldy foods, but more importantly in foods which upon visual examination or inspection appear to be suitable for direct human consumption. Aflatoxins can be retained in both cake and crude oil after extracting oil from nuts. If dairy cattle consume aflatoxin-contaminated feeds, such as copra cake or meal, aflatoxin B1 is metabolized in the body and secreted in milk as aflatoxin M1. In the Philippines, the growth of the aflatoxin-producing fungi is favored by climatic conditions, i.e., high temperature coupled with high relative humidity (80-90 %, wet season and 50-70 %, dry season). Aflatoxin contamination and feed commodities in agricultural crops, food especially cereals, legumes and oilseeds is a serious problem in the country. Among the agricultural crops studied so far, those that have been found to contain variable levels of aflatoxins are corn, peanuts, rice, cassava and coconuts and their products Survey of aflatoxins Surveys on the aflatoxin contamination of agricultural commodities were conducted by various research groups which revealed that corn and peanuts and their by-products were the two commodities that contained toxic levels of aflatoxin (<3-1,500 ƒêg/kg for corn and <3-8,600ƒÊg/kg for peanuts). The surveys showed that raw dried whole corn and peanut butter had the highest aflatoxin contents. The Bureau of Food and Drug (BFAD) under the Department of Health has been undertaking food inspections in food establishments, supermarkets, public markets and small stores to check compliance with product specifications and standard. The incidence of aflatoxin contamination of samples collected from Metro Manila supermarkets by random sampling for the period 1992 to 2002, as part of BFAD monitoring activities, is shown in Table 1. The results revealed that there is an improvement on the aflatoxin contamination of the commodities through the years. This indicated the quality control on the acceptance of the raw materials by the food processors leading to the improvement in the quality of their food products. For
169 aflatoxin, the USFDA limit of 20ƒÊg/kg aflatoxin B1 is being enforced as the tolerance level for aflatoxin in the Philippines. The Philippine Coconut Authority (PCA) data on the aflatoxin levels of copra meal collected in different regions of the Philippines in 1988 showed that no sample had Table 1. Incidence of aflatoxin contamination in samples of peanut butter, peanut confections and assorted nuts, and corn-based products analyzed over the period 1992-2002. a -, not determined Data from Salariosa et al. 1995, BFAD 1998 (Unpublished) and BFAD, 2002, Table 2. Aflatoxin contamination of copra meal in the Philippines. ND - not detected Data from PCA, 2003.
170 levels above 50ƒÊg/kg. Of the 39 samples analyzed, 41.7 % had non-detectable levels of aflatoxin; 44 % had 1-19ƒÊg/kg AFB1; and 8.3 % had 20-50ƒÊg/kg AFB1. On the other hand, copra meal (expeller and copra meal combined) samples tested from the different regions revealed that one out of 136 samples had an aflatoxin content of above 200ƒÊg/kg (0.7 %); 33.8 % samples contained 50-199ƒÊ g/kg AFB1; 30.9 %, 30-49ƒÊg/kg; 13.2 %, 10-29ƒÊg/kg; and 21.3 %, 1-19ƒÊg/kg. This indicated a 34.5 % acceptance level in the Netherlands and 65.4 % in the German market. Data obtained by the PCA for aflatoxin contamination of copra meal in the country showed that samples from Region XII (General Santos and Cotabato) gave the highest toxin contamination (Table 2), Table 3. Aflatoxin levels in corn collected in different regions of the Philippines from 1997 to 1998. a Expressed in ƒêg aflatoxin B1/kg sample Source: Arim et al. 1999, quantitated by HPLC. Table 4. Aflatoxin contamination of processed corn products collected in the Philippines. a Expressed in pg aflatoxin B1/kg sample, quantitated by HPLC. Source: Arim et al. 1999
171 followed by Region XI (Davao). The results were attributed to the climatic conditions in the area where difficulty in the drying of the copra was encountered. Occurrence of aflatoxins in corn is shown in Table 3. Data indicated that corn collected from Iloilo and South Cotabato contained higher aflatoxin contamination that those obtained from Ilocos and Isabela. Processed corn products contained aflatoxin levels below the 20ƒÊg/kg tolerable limit (Table 4), except for fried corn with a mean of 3ƒÊg/kg AFB1. Corn samples from South Cotabato analyzed in 2003 gave higher aflatoxin values: 4-208ƒÊg/kg than those from Ilocos and Pangasinan, ND - 10ƒÊg/kg (Table 5). The aflatoxin contamination of feed corn (Table 6) showed that whole corn samples gave higher toxin values than corn grits and cracked corn. Tables 7 and 8 show the aflatoxin levels of feeds for poultry and hogs from 1992 to 2002; data showed a higher contamination in poultry feeds (max=793ƒêg/kg) than in hog feeds (max=710ƒêg/kg); higher toxin contamination of poultry and hog feeds was observed in 2002 than in the previous years. Table 5. Aflatoxin contamination of corn collected in 2003. ND - not detected Table 6. Aflatoxin content of feed corn collected in the Philippines. a Expressed in ig aflatoxin B1/kg sample, yuantitated by HPLC. Recommendations Mycotoxin, particularly aflatoxin contamination in agricultural crops such as corn
172 Table 7. Aflatoxin contamination of poultry feeds in the Philippines (1992-2002). Source: BAI, 2003 Table 8. Aflatoxin contamination of hog feeds in the Philippines (1992-2002). Source: BAI, 2003 still remains a big problem in the country. Farmers, traders and consumers should be properly educated on how to solve the problem through seminars, workshops and demonstrations at the grassroots level. Based on the aflatoxin surveys conducted, corn and copra meal are the identified commodities that need attention, since corn is being used as staple food by Filipinos in Central Visayas and Mindanao area while copra meal is an export product used as feeds
173 for dairy cows in the European Union. Monitoring and surveillance studies should be continued in all aflatoxin-susceptible agricultural crops and their food and feed products; the data obtained will serve as basis for setting the aflatoxin regulatory limits in the country. Problems and research needs for the control of aflatoxin contamination identified by a group of researchers involved in mycotoxin work include analytical methods adaptation/validation, development of in-house reference materials, upgrading of laboratory capabilities, establishment of mycotoxin laboratories in corn-producing regions, and education of farmers, traders, consumers and legislators. A program on the dissemination of the nature and effects of mycotoxins, particularly aflatoxins, in radios and televisions should be encouraged as a way to educate the people. Furthermore, BFAD should continue testing market products to ensure the safety of the foods for human consumption, as well as, to safeguard the health of the consumers. To solve further the potential hazard of aflatoxin contamination, regulations have to be set so that the food and feed industries, as part of their operating procedures, monitor the aflatoxin contents of raw products used for processing and prohibit use of contaminated substrates for processing. References 1) Santamaria, P.A., Pizarro, A.C., Jackson, C.R.: Philippine Phytopathology, 8,12-20 (1972) 2) Salamat, L.A., Dumada-ug, L.M.: Paper presented at the 3rd FNRI Seminar Report Series, FNRI, Manila, Philippines (1977) 3) Garcia, V.V., Rubico, S.M., See, F.S., Almario, M.A.R., Maligalig, I.: Terminal Report of Peanut-CRSP-UPLB-PCARRD Project 88-876-021. Institute of Food Science and Technology, University of the Philippines at Los Banos, College, Laguna (1988) 4) National Postharvest Institute for Research and Extension (NAPHIRE): Annual Report, Nueva Ecija, Philippines (1988) 5) Salariosa, AH, Lucero, J.P., Parce, C.J.: BFAD Laboratory Information Bulletin (1995) 6) Bureau of Food and Drugs Administration: Aflatoxin Monitoring of Selected Processed Products, BFAD, Muntinlupa City, Philippines (2003) 7) United Coconut Association of the Philippines (UCAP): Aflatoxin Contamination in Philippine Copra and Copra Meal, p. 10-12, UCAP, Philippines (1989) 8) Philippine Coconut Authority: Aflatoxin Contamination of Copra Meal in the Philippines, PCA, Quezon City, Philippines (2003) 9) Arim, R.H., Ferolin, C.A., Ramirez, R.P., Aguinaldo, A.R., Yoshizawa, T.: Proceedings of the International Symposium on Mycotoxicology '97, Chiba, Japan pp. 193-196 (1999) 10) Begino, E.T.: Aflatoxin Contamination of Feeds in the Philippines, Bureau of Animal Industry, Quezon City, Philippines (2002)