Regulations on Creation and Sale and Purchase of Dried Figs (Part II)
- An integrated pest management programme must be applied and fruits or vegetables that promote infestation with dried fruit beetles or vinegar flies should be removed from the fig orchards since these pests act as vectors for the transmission of fungi especially into the fruit cavity. Pesticides approved for use on figs, including insecticides, fungicides, herbicides, acaricides and nematocides should be used to minimise damage that might be caused by insects, fungal infections, and other pests in the orchard and adjacent areas. Accurate records of all pesticide applications should be maintained.
- Irrigation should be implemented in regions or during periods with high temperatures and/or inadequate rainfall during the growing season to minimise tree stress, however, irrigation water should be prevented from contacting the figs and foliage.
- Water used for irrigation and other purposes (e.g. preparation of pesticide sprays) should be of suitable quality, according to the legislation of each country and/or country of import, for the intended use.
- Caprifigs (male fig fruits) are important for fig varieties, which require for fruit set. Caprifigs should be healthy, free from fungi and should have plenty and live pollen grains and wasps (Blastophaga psenes L.). During pollination of female fig fruits by fig wasps, which pass their life cycle in caprifig fruits, Fusarium, Aspergillus spp. and other fungi can be transported to the female fig fruits from the male fruits through these wasps. Since male trees are the major sources of these fungi, male trees are generally not allowed to grow in female fig orchards. It is important to use clean caprifigs, rotten and/or soft caprifigs should be removed prior to caprification. Because caprifigs, which are allowed to stay on the tree and/or in the orchard, can host other fungal diseases and/or pests therefore after caprification they must be collected and destroyed outside the orchard. To make the removal of caprifigs easier, it is recommended to place caprifigs in nets or bags.
- All equipment and machinery, which is to be used for harvesting, storage and transportation of crops, should not constitute a hazard to health. Before harvest time, all equipment and machinery should be inspected to ascertain that they are clean and in good working condition to avoid contamination of the figs with soil and other potential hazards.
- Trade Associations, as well as local and national authorities should take the lead in developing simple guidelines and informing growers of the hazards associated with aflatoxin contamination of figs and how they may practice safe harvesting procedures to reduce the risk of contamination by fungi, microbes and pests.
- Personnel that will be involved in harvesting figs should be trained in personal hygienic and sanitary practices that must be implemented in processing facilities throughout the harvesting season.
- Harvesting of dried figs is different from harvest of figs for fresh consumption. The figs to be dried are not harvested when they mature but kept on the trees for overripening. After they lose water, partially dry and shrivel, an abscission layer forms and the fig fruits naturally fall from the trees onto the ground. The most critical aflatoxin formation period begins with ripening and continues when shriveled until fully dried. The fig fruits need to be collected from the ground daily to reduce aflatoxin formation and other losses, caused by diseases or pests. On the other hand, the collecting containers should be suitable, preventing any mechanical damage and should be free of any fungal sources and clean.
- Dried fig harvest should be done regularly at short intervals daily to minimize the contacts with soil and thus contamination risks. Frequent harvest also reduces insect infestation especially of dried fruit beetles (Carpophilus spp.) and fig moths (Ephestia cautella Walk. and Plodia interpunctella Hübner).
- In case of a significant difference between day and night temperatures, dew formation that may trigger aflatoxin production may occur. This is important since wet surfaces favouring the growth of fungi may be formed even after complete drying of the fruit.
- Drying area and time are important factors in aflatoxin formation. The moisture content of the partially dried and shriveled fig, fallen down from the tree, is approximately 30-50% and these fruits are more susceptible to physical damage than the fully dried fig fruits that have approximately 20-22% moisture content. Good soil management that reduces particle size and smoothens the surface before harvest is therefore necessary to reduce the risk of damaging.
- Fig fruits can be dried artificially in driers or under the sun with the help of solar energy. In artificial driers, the fig fruits are dried in a shorter period and more hygienic products with less pest damage can be obtained. Good drying practice can help preventing aflatoxin formation. Sun-drying is cost efficient and environmentally friendly, however may as a result increase the likelihood of aflatoxin contamination.
- Fruits shall not be placed directly on the soil surface or on some vegetation. Drying beds should be arranged as single layers in a sunny part of the orchard where air currents are present. The drying trays shall be covered with a material to protect the figs from rain fall in case there is a risk or to prevent infestation of fig moths that lay eggs in the evening. Drying trays that are 10-15 cm above the ground should be preferred in sun-drying since fruits can benefit from the heat at the soil surface and are well aerated. They can dry quickly and the contamination of fruits by foreign materials and sources of infection such as soil particles or plant parts are eliminated.
- Figs that are dried, possessing moisture = 24% and water activity = 0.65, should be picked from the trays. The fully dried fruits should be collected from the trays preferably in the morning before the temperature of the fruits increase and soften but after the dew goes away. The trays should be re-visited at short intervals to collect fully dried figs. Dried figs taken from drying trays must be treated to prevent storage pests with a method allowed in the legislation of each country, for the intended use.
- Low quality figs which are separated as cull and have the risk of contamination should be dried and stored separately to prevent cross contamination. Staff who conduct the harvesting or work in storage rooms should be trained in this respect to ensure that these criteria are followed.
If transportation is required the following provisions apply:
- During the transportation of dried figs from farm to processor, the quality of figs should not be affected adversely. Dried figs should not be transported with products that pungent odours or have the risk of cross contamination. During transportation, increase of moisture and temperature must be prevented.
- The dried figs should be moved in suitable containers to an appropriate storage place or directly to the processing plant as soon as possible after harvesting or drying. At all stages of transportation, boxes or crates allowing aeration should be used instead of bags. Containers used in transportation shall be clean, dry, and free of visible fungal growth, insects or any other source of contamination. The containers should be strong enough to withstand all handling without breaking or puncturing, and tightly sealed to prevent any access of dust, fungal spores, insects or other foreign material. Vehicles (e.g. wagons, trucks) to be used for collecting and transporting the harvested dried figs from the farm to drying facilities or to storage facilities after drying, should be clean, dry, and free of insects and visible fungal growth before use and re-use and be suitable for the intended cargo.
- At unloading, the transport container should be emptied of all cargo and cleaned as appropriate to avoid contamination of other loads.
- Figs must be properly cleaned, dried and labelled when placed in a storage facility equipped with temperature and moisture controls. The shelf life of dried figs can be prolonged, if they are dried to a water activity value at which molds, yeasts and bacteria cannot grow (water activity<0.65). In case further hot spots are formed where temperature and moisture increases, secondary aflatoxin formation may occur. Because of this reason, any possible source enhancing humidity of the dried fruits or of the surrounding environment must be eliminated. Direct contact of dried fig containers with floors or walls need to be prevented by placing a palette or a similar separator.
- The storage rooms should be far from sources of contamination as in the case of mouldy figs or animal shelters if any are present at the farm, and fruits must not be stored with materials that possess unusual odours. Precautions should be taken to avoid insect, bird or rodent entrance or similar problems especially under farm storage conditions.
- Low quality figs that are not destined for direct human consumption should be stored separately those intended for human consumption. The storage rooms should be disinfected with effective disinfectants. Areas like cleavage and cavity should be repaired and windows and doors should be netted. The walls should be smoothened and cleaned every year. The storage rooms should be dark, cool and clean.
- The optimum storage conditions for dried figs are at temperatures of 5-10 °C and relative humidity less than 65%. Therefore, cold storage is recommended.
- Dried figs are fumigated, stored, sized, washed, cleaned, sorted and packed in processing units. Among these processes, removal of aflatoxin-contaminated figs, storage and package material may exert the major impact on aflatoxin levels of the final products. Processed figs must be treated to prevent storage pest with a method allowed in the legislation of each country for the intended use.
- Dried fig lots entering into the processing plant must be sampled and analyzed as an initial screening for quality moisture content and ratio of bright greenish yellow fluorescent (BGYF) figs. Dried figs contaminated with aflatoxins can have a correlation with BGYF under long wave (360 nm) UV light. BGYF may occur on the outer skin but also inside the fruit cavity; the ratio being dependent on the fruit characteristics and on prevalence of vectors. Dried figs fruits are examined under long wave UV light and the fluorescent ones are removed to obtain a lower aflatoxin content of the lot. Work conditions such as the length of working, break intervals, the aeration and cleanliness of the room, should provide worker safety and product safety.
- Contaminated figs must be separated, labelled and then destroyed in an appropriate manner in order to prevent their entry into the food chain and further risk of environmental pollution.
- The moisture content and water activity level of dried fig fruits must be below the critical level (moisture content can be set at 24% and water activity of less than 0.65). Higher levels may trigger fungal growth and toxin formation. Higher water activity levels may trigger aflatoxin formation in areas of high temperature storage at the processing plant or at retail level especially in moisture tight packaging material.
- Dried figs are washed if demanded by the buyer. The water temperature and the duration of washing should be arranged according to the moisture content of the figs in order to avoid the elevation of the initial moisture content of fruits to critical levels. In case the moisture and water activity levels are increased, a second drying step must be integrated in the process. The water should have the specifications of drinking water.
- Good storage practices must be applied at the processing plant and should be kept at this standard until the product reaches the consumer (see section 3.8).
- All equipment, machinery and the infrastructure at the processing plant should not constitute hazard to health, and good working conditions should be provided to avoid contamination of figs.
- These recommendations are based on current knowledge and can be updated according to the research to be pursued. Preventive measures are essentially carried out in fig orchards and precautions or treatments undertaken at the processing stage are solely corrective measures to prevent any aflatoxin formation.