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Home>FFTC Document Database>Extension Bulletins>Safety Management and Inspection of Agrochemical Residues of Food in the Trade of Export Products: A Case Study of the Taiwan-Grown Irwin Mango
Safety Management and Inspection of Agrochemical Residues of Food in the Trade of Export Products: A Case Study of the Taiwan-Grown Irwin Mango
Chin-Wen Kao, Shu-Jen Tuan and Hong-Ping Li
Taiwan Agricultural Chemicals and
Toxic Substances Research Institute (TACTRI)
11 Kung-Ming Rd., Wufeng, Taichung, Taiwan ROC, 2009-04-07


Irwin mango orchards in Taiwan comprise more than 8,000 acres of agricultural land, mostly in Tainan and Pingtung Counties in southern Taiwan. Total annual yield during the May-August season is 80,000 metric tons. The high quality and sweet taste of Taiwan-grown Irwin mangoes are well recognized by consumers both in domestic and abroad, particularly the Japanese. In recent years, export volume and foreign demand have substantially increased. To improve the safety and quality of this product and to avoid international trade obstacles posed by differing maximum residue limits (MRLs) in various countries, the Council of Agriculture (COA) has established a food safety management program specifically, for the exporting excellent mango supplying orchards. The system provides registration for farmers and exporters, certification of exporting orchards, guidance for establishing an integrated pest control system with reduced use of pesticides, implementation of a double pesticide residue detection, pre-harvesting and pre-exporting system and a barcode labeling operation and tracking system. The COA has also lobbied to enact legislation for the passage of legislation requiring documentation of export applications. Conversely, Taiwan Agricultural Achemicals and Toxic Substances Research Institute (TACTRI), the authorized research institute and accredited laboratory, has implemented improved produce monitoring systems and upgraded the multi-residue analysis method to achieve a lower limit of detection for a broader spectrum of pesticides. The education program and technical training courses are the core activities of the organization. A comprehensive process of safety quality control, from cultivation management to pesticide residue inspection and steam-heating treatment in quarantine station, has enabled the successful export of 784 metric tons of Irwin mangoes to Japan during May to the early August 2007, an export volume of 180% more than that of 2006. Notably, export volume of Irwin mangoes to other foreign countries, including Korea, Hong Kong, China, Australia, Singapore, has also increased annually. This increase clearly demonstrated the effectiveness of efforts to increase exports of Taiwan-grown mangoes after implementing practices for safely managing of agrochemical residues.

Key words: safety management, agrochemical, residues, trade, export, Taiwan mango


Irwin mangoes yield abundantly in southern Taiwan from May to July. Their unusual sweet flavor and pleasant fragrance make them particularly popular among consumers both domestically and abroad. It makes a product with high export potential and has the reputation enjoyed by apple mango in Japan. The Council of Agriculture (COA) has striven to launch Taiwan agricultural products in global markets. After three years of negotiation, Australia officially announced in May that Taiwan-grown mangoes, after treatment by steaming, are eligible for export to Australia. For the first time, Taiwan-grown fruits have been allowed entry to a country with such strict quarantine requirements. This breakthrough is significant to the development of Taiwan-grown fruit exports. To increase the export volume of Taiwan-grown mangoes, the COA entrusted the Taiwan Vegetable and Fruits Export Association with organizing the travel of exporters to Australia to conduct a holistic promotion campaign. A series of promotional campaigns in coordination with distribution channels of traders was also conducted simultaneously in major Australian supermarket chains. Further, the "Have-a-Taste" promotional campaign in several large cities introduced Australian consumers to the unique taste of Taiwan-grown mangoes. Another encouraging development was the July 30, 2007 poll conducted by Yahoo in Japan to determine the most popular fruit produce. The Taiwan-grown Irwin mango was the overall champion with 36,264 votes constituting 73% of respondents.

The high quality and good taste of the Irwin mango should ensure its successful export to Japan. Unfortunately, the Japanese government recently announced a new food safety regulation policy, the "Japanese Positive

List System of Agricultural Chemical Residues in Food", which has been extremely alarming to Taiwan produce exporters. From May 29 to the end of July, 2006, fifteen shipments of mangoes were rejected by Japanese inspectors, mainly due to detection of very low levels of Cyfluthrin (0.03~0.06ppm) and Cypermethrin (0.04~0.07ppm). These findings resulted from pesticide use by farmers during the flowering and young fruit period to control damage caused by mango-leafhopper. Even farmers who strictly obeyed the pre-harvest intervals and government regulations regarding pesticide concentrations still produced mangoes with minor residue. Although the product was in compliance with the Taiwan limit of MRL (0.5ppm), it exceeded the Japanese limit of Cyfluthrin (0.02ppm) and Cypermethrin (0.03ppm) respectively. Import quarantine laws and restrictions vary between countries, especially the Maximum Residue Limits (MRLs) of agrochemical residues in food. Differing MRLs between countries can significantly impede international trade in Agro-products. To ensure the success of exports to Japan and other industrialized countries, improving the management and regulation of farmers and exports is vital. Efforts are needed in all aspects of produce inspection, from planting to post-harvest. Further, a strict double-inspection process is needed for analyzing pesticide residue to ensure food safety.

Education and Traceability Program for Safety Guidance

Of practical importance is the concept that the traceability system as the first step in ensuring an effective food safety quality program. As agriculture relies on the climate and environmental conditions, it is inevitably affected by natural factors such as soil and irrigated-water, climate, pests and diseases. In addition to the stress associated with planting and farm management, globalization and free trade have had an also impact on domestic agriculture since Taiwan joined the WTO. Therefore, the current agriculture policy is intended to guide domestic agriculture toward increased production of "value-added" products by transforming traditionally labor-intensive industries into knowledge-based industries to elevate the competitiveness of Taiwan agriculture. In an era of growing consumer awareness and sophistication, "food quality" is increasingly emphasized and valued. So-called "food quality" refers not only to external appeal, taste and freshness; safety is now the priority. Food safety means that agro-products should undergo a certification process and be evaluated according to MRLs. Therefore, aspects of farm management such as the following should be closely monitored: sources of seeds and seedlings, pests and weed elimination, pesticide application, dates and amounts of fertilization, harvesting or post-harvesting treatment and basic information regarding the individual farmer. The entire production-marketing process should regulate not only farm management, but also transportation and retailing. Information should be accurately recorded, transparent, traceable and auditable by the third party. A traceability system is vital to ensure the accuracy of all information from farm to table. By way of individualized counseling from technical service teams, export-orchard farmers can be adequately educated and informed regarding the latest data and methods regarding pest control. Each farmer should be required to maintain current records of any activity involving production marketing. All production and marketing processes are readily available by internet. This "Safe Agricultural Production and Marketing System" established by agricultural authorities and production units enable the public to shop and consume without safety concerns. Developing safe and high quality product is meant to do more than protect the interests of consumers in Taiwan. As international trade liberalizes, safe agriculture enhances the international competitiveness of Taiwan agriculture. For farmers, value upgrade increases earnings. Production and marketing groups or individual farmers producing safe agricultural products must ensure quality and establish trust and reliance between producers and consumers. All well-informed farmers who export produce must maintain accurate records either by hard or soft copy of all documents.

Specified Safety Management System —from Pest Control to Harvesting

Import quarantine laws, restrictions and MRLs of agrochemicals in food vary widely between countries. Simultaneously meeting the safety standards of both Taiwan and Japan may be difficult, especially for the in_season Taiwan-grown Irwin mangoes because of the wide variation in MRLs ( Table 1(1386)). To ensure mango exports meet domestic and foreign safety standards, exporters of agro-products destined for foreign countries should ensure production-marketing groups contact the proper authorities to clarify overseas quarantine regulations. For example, to comply with the new pesticide residue inspection policy implemented by Japan from May 29, 2006, the COA established a registration system requiring all exporters of mangoes to Japan to register with the COA. The exporters are required to submit a list of farmers, which had trade agreements with them. According to the list, the Agriculture and Food Agency (AFA) staff are responsible for auditing the orchards and farmers. Qualified farmers then receive serial numbers and identification codes. However, one problem with the management program for pesticide usage is the differing MRLs between Taiwan and Japan. To clarify the information and guidelines for pesticide usage in compliance with regulations of Taiwan and Japan, the Bureau of Animal and Plant Health Inspection and Quarantine (BAPHIQ) has developed guidelines for exporting-orchard farmers. The recommendation pesticide application list is divided into three parts according to the differing MRLs between Taiwan and Japan, which are marked in blue, yellow or red ( Table 2(1501), Table 3(1128), Table 4(1218)). Aside from complying with the Plant Protection Manual, farmers must also comply with the guidelines for exporting-orchard management and consult the technical service team supervisor. The officers and researchers of the county government, AFA, BAPHIQ, District Agriculture Improvement Station (DAIS) and TACTRI hold training courses and awareness campaigns regarding the recommended pest management practices in mango orchards. Additionally, they also educate farmers to comply with pre-harvest intervals and to minimize pesticides by properly using non-agrochemical materials. The orchards registered as excellent mango suppliers are assisted in implementing quality control procedures for all of their production processes. All farmers are also required to use fruit envelopes as early as possible to erase the damage caused by the oriental fruit fly and to avoid unnecessary pesticide use after enveloping. All information is also available online at or Before harvesting the mangoes, exporters should perform sampling process from orchard to orchard for pesticide residue inspections of exporting mangoes. The registered orchards/growers should ensure that no pesticides are used in the orchard once the sample was drawn for residue analysis. Thus far, all pesticide residue analyses of mango exports have been performed by TACTRI. After testing for pesticide residue, TACTRI sends an e-mail or fax to all concerned entities including concerned farmer. Only farms that pass the pesticide residue inspection are permitted to harvest their mangoes. Samples exceeding the MRLs of Japan are prohibited from harvest and further investigated to determine the cause of failure.

Safety Certification Mechanism

Labeling and Double Inspection of Residues

Regulations for post-harvesting processing procedures have also been established. The EAN-128 International Commercial Bar-Code system is to be used for convenient tracking and tracing of information regarding product production and distribution. Accurate labeling after harvest is critical, and all mangoes are tracked by a quality control tracking system. Government guidelines specify procedures for coding and labeling mango to clearly indicate the standard operation procedure (SOP). After selecting and screening treatment at the gathering place, the high quality mangoes are collected and labeled individually. The EAN-128 Bar-Code card label is also affixed to each basket, and all baskets are transported to steam processing quarantine stations. The AFA officers confirm all documents, including export-application sheet-the most recent pesticide residue report and pesticide usage record. The quantity of produce intended for export is then checked. After finishing all preparation procedures, a sampling inspection is again performed to examine individual batch of mangoes applied by each exporter. The second-round pesticide residue inspection is still conducted by TACTRI, and the report should be accomplished in 24 hrs to minimize the economic impact on exporters. The Act and rules regarding the procedure for auditing and approving the export-application agreement document have also been strictly modified. The AFA officers issue onsite certification to those who pass the serial inspection processes. This process ensures that all produce is suitable for export to Japan. The county government immediately destroys all substandard samples at a steam-heating processing quarantine station if the pesticide residues exceed the safety standards of both Taiwan and Japan. Notably, the COA has substantially improved their quarantine technology and facilities. Four recently established quarantine stations are expected to considerably increase the steam-heating processing capacity of fresh fruit exports to Japan as well as volume and value of produce exports. Future data regarding post-harvesting processing procedures for stocking farms and steam-heating treatment procedures are to be made available for internet access. To further expand the export market for Taiwanese fruit, the council is studying effective quarantine and pest control techniques needed for certification in various countries.

Inspection Procedure and Improving Pesticide Residue Analysis

Samples of fruits ready for harvest are to be taken from at least one tree at each of five different locations in north, south, east, west and central areas of the orchard. At least three fruits must be taken from each tree at different heights. All sampled mangoes are to be packed in a provided bag with the signatures of the farmer, trader/exporter and a representative of the concerned officer. It is then express mailed to a TACTRI laboratory. The application sheet attached to the sample bag gathers information including the name of the farmer/packinghouse/exporter, registration number, location address, crop/variety, date of sampling, person in charge of sampling, harvesting date, exporting date and country. After the AFA officer samples the mangoes in steam-heat treatment stations, each batch of mangoes is then put into a polythene bag and sealed for delivery to TACTRI for follow-up analysis. Related information and documents should also be included in the bag, such as the most recent analysis report, export volume and the essential reference data mentioned above. To realize the impact of analysis methods of the Positive List System for Agricultural Chemical Residues in Foods implemented by the Ministry of Health, Labor and Welfare of Japan, senior TACTRI/COA researchers have visited the Tokyo and Yokohama Quarantine Station. They met with staff and inspectors to gather information regarding analysis methods. To ensure that chemical residue monitoring becomes an established practice and that the results are sufficiently representative, TACTRI investigated the pesticides commonly used by mango farmers and compared their MRLs with those of Taiwan and Japan. A checklist of detected pesticides was then produced. Approximately 250 pesticides were selected for investigation to establish a multi-residue analysis method for mango exports. Samples were extracted with acetone. Clean-up was performed by liquid partitioning from aqueous solution to petroleum ether and dichloromethane followed by a Florisil column chromatography. The extracts were analyzed by temperature-programmed gas chromatography (GC) with detectors such as FPD (or NPD) and ECD, high performance liquid chromatograph (HPLC) with OPA post-column reaction and fluorescence detector and HPLC with UV absorption detector. To comply with the Japanese detection limit for pesticide residue, TACTRI also pplied the same analytical method used by the Japanese government and detected each batch of fruit exports with GC/MS and GC/MS/MS. This improved detection method is consistent with trends in the food inspection practices of other advanced nations. So far, TACTRI has established analytical methods for detecting more than 350 pesticides simultaneously with GC/MS and LC/MS/MS, which includes all possible pesticides available to farmers in Taiwan. TACTRI has also established a virtual personal network (VPN) to remotely control the operation and analyzed data from each inspection station and then confirm the final report. All analyses of steam-heat station samples are to be completed in 24 hrs and immediately e-mailed or faxed to the concerned exporter, AFA officer or quarantine station before final processing and signing of documents for export to Japan.


Taiwan-grown Irwin mangoes supplied to domestic and foreign markets during the May-August season play an important role in the Taiwan produce industry. This fruit is favored not only by consumers in Japan but also those from Korea, Australia, Hong Kong, Singapore and China. This year, Irwin mango exports to Japan reached 780 metric tons as of the end of July 2007, a growth of 80% over the 430 metric tons exported last year. Additionally, export data show that Taiwan-grown mango exports to Korea reached 728 metric tons this year, a 3.9-fold increase over the 147 metric tons exported in 2005. Further, after years of negotiation with the Bureau of Animal and Plant Health Inspection and Quarantine of Australia, the first exports to Australia comprised 77 metric tons. For Taiwan, this achievement heralds only the beginning of a new era of produce exports to the southern hemisphere. After decades of development, techniques for producing and cultivating Taiwan mangoes have been perfected. The most important means of increasing the competitiveness of agro-product exports is to continue improving and enhancing the management of agrochemical residues. The 2007 goals for Taiwan fruit exports abroad have been achieved. Implementation of the above measures would allow consumers in Taiwan and abroad to enjoy the unique flavor of Taiwan-grown mangoes with safety concerns.


Index of Images

Table 1 The MRLS for Mango Set by Japan and Taiwan

Table 1 The MRLS for Mango Set by Japan and Taiwan

Table 2 The MRLS of Japan and Taiwan Are Similar for the Following Pesticides. Hence, Farmers Should Obey the Phi

Table 2 The MRLS of Japan and Taiwan Are Similar for the Following Pesticides. Hence, Farmers Should Obey the Phi

Table 3 The MRLS of Japan Are Slightly Lower Than That of Taiwan for the Following Pesticides Hence, Farmers Should Use the Following Pesticides Carefully and in the Early Stage of Planting

Table 3 The MRLS of Japan Are Slightly Lower Than That of Taiwan for the Following Pesticides Hence, Farmers Should Use the Following Pesticides Carefully and in the Early Stage of Planting

Table 4 The MRLS of Japan Are Extremely Lower Than That of Taiwan for the Following Pesticides. Hence, Farmers Should Avoid to Use the Following Pesticides in the Export Mango Orchard through the Whole Production Process

Table 4 The MRLS of Japan Are Extremely Lower Than That of Taiwan for the Following Pesticides. Hence, Farmers Should Avoid to Use the Following Pesticides in the Export Mango Orchard through the Whole Production Process

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