Post-Harvest Handling of Orange Önder KABAS Bat Akdeniz Agricultural Research Institute, 07070 Antalya, Turkey Abstract Worldwide postharvest fruit and vegetables losses are as high as 30 to 40% and even much higher in some developing countries. Reducing postharvest losses is very important; ensuring that sufficient food, both in quantity and in quality is available to every inhabitant in our planet. The prospects are also that the world population will grown from 5.7 billion inhabitants in 1995 to 8.3 billion in 2025. World production of vegetables amounted to 486 million ton, while that of fruits reached 392 million ton. Turkey produces most of its vegetable itself due to various suitable and climate regions around the country. Reduction of post-harvest losses reduces cost of production, trade and distribution, lowers the price for the consumer and increases the farmers income. resh fruits and vegetables are inherently perishable. During the process of distribution and marketing, substantial losses are incurred which range from a slight loss of quality to total spoilage. Post-harvest losses may occur at any point in the marketing process, from the initial harvest through assembly and distribution to the final consumer. The causes of losses are many: physical damage during handling and transport, physiological decay, water loss, or sometimes simply because there is a surplus in the marketplace and no buyer can be found. Oranges are grown in commercial quantities in the field. Consumers buy oranges primarily for their size but are attracted to repeat purchases by flavor and quality. This study focuses on the post-harvest operations of Oranges in Turkey. The post-harvest operations carried out in packinghouses include some or all of the following; dumping, washing, pre-sizing, waxing, sorting, grading, sizing, packing and storage. Keywords: packinghouse, handling, sorting INTRODUCTION Value of fruits and vegetables, (as an important source of vitamins and minerals) is being understood more and more by consumers each day. There is a growing need of fruit and vegetables on world market. Therefore, fruit and vegetables have a fast growing market share. Turkey has many different varieties of soil, different climates and water sources. Because of this, Turkey has many different species of fruits and vegetables. According to surveys; 140 of different vegetable species and 80 of different fruit species are being grown in our country ( llez, 2001) Turkey from the entire agricultural production 24.31% (26.8 million tons) are vegetables, 23.26% (16.6 millon tons) are fruits (TUIK, 2009). Total fresh fruit production is about 43 million tons. Fresh orange fruit export is about 1.5 millon tons. Significant damages are being occurred in the process of growing, harvesting, and post-harvesting, on fruits and vegetables. This causes losses on farmers and also on country s economy. Reducing the damages occurring on production and post-production
and inspecting every units of production have a great role on quality of fruits and vegetables served in the markets. As surveys indicate, 25% of fruits gets rotten in the time of delivery from producers to consumers. This ratio gets up 30% on vegetables (Alan and Padem, 1993; Dokuzo uz 1984). These losses which occur in process of harvesting, conserving and marketing depend on the product and get up to 50-60%. These losses on production units have taken in to the minimal ratios in the countries, which has advanced technology on fruit growing. Well planed units on production and post production should be built to increase the export potential. Problems faced on fresh fruit production are as in postproduction packing, conserving and transporting sequences, which has supported by improperly organized companies. To get in to world major fruit and vegetable exporting countries, our fruit and vegetable production sector should be organized regarding the international quality standards and worldwide criteria Processes of preserving the production and getting them ready for the markets are being done in the packinghouse. These facilities have been built to meet different capacities of production and different needs of customers. Most tomato packinghouses are large, sophisticated, high volume operations. Upon transfer to packing line (dumping), oranges are washed, waxed, sized, sorted, graded, packed and storage. PACKINGHOUSE OPERATIONS Packinghouse have been built in our country for oranges to carry out dumping, waxing, washing, sorting, sizing, grading, packing and storage. These are explained below; DUMPING and WASHING Water dump tanks are routinely used for receiving oranges at the packinghouse and sometimes dumped into conveyor (Figure 1) When used dump tanks, in this manner, harvested oranges can be washed and cleaned from dust, soil and other material before operations. A simple washing conveyor was shown Figure 2. Pallet bins are emptied in to the dump tank by hand or mechanically. Small boxes and chest are emptied by hand, big and heavy pallet bins by mechanically. Two methods are used to empty bin into dump tank. In the first method, the bin contents are tipped into a feeder hopper by either a forklift mounted tippler, or a static tipping cage. Some static cages do not need separate power for tipping, the forklift tines being used to lift the rear edge. To minimize damage when tipping oranges, the cage should tip the bin around its front edge (Figure 3a). In the second method, the bin is directly intake conveyor or dump tank without an intermediate feed hopper. This uses a powered tip cage, controlled by either a crop flow sensor (Figure 3b). The following is a summary of the suggested dump tank management practices to eliminate these problems: Minimize the dept to which oranges are submerged when dumped, to less than 60 cm Maintain a single layer of oranges in the dump tank Minimize the time oranges speed in the dump tank, less than two minutes. Never leave oranges standing in the water during packinghouse crew breaks. Modify dump tanks to climinate dead spots
Chlorinate dump tank and wash water to maintain a free chlorine concentration of 100 to 150 parts per million (mg/l) Adjust water ph about 7.0 Maintain the dump tank water temperature higher than highest fruit pulp temperatures. Water heating requirements can be minimized by keeping harvested fruit in the shade. Temperatures should be monitored with thermometer. These management practices represent additive control efforts-not alternative methods. Use of a single control parameter (like chlorination) has not proved to be sufficient to prevent post harvest decay during disease-favorable conditions. PRE-SIZING Following washing, undersized oranges are eliminated by use of a perforated belt sizer. Smaller oranges drop through the belt and are conveyed to the cull chute. This step eliminates undersized fruits and prevents them congesting the packinghouse operations which fallow WAXING Most oranges are waxed prior to packing with good grade wax labeled for use on oranges. Waxing serves to reduce water loss during marketing, but it is done primarily to improve the luster of oranges (Figure 4) RINSING AND DRYING After the washing process, oranges should be rinsed and dried properly in order to repel the disinfectants and other chemical material. Drying can be made by sponges or brushes and also with hot air (Figure 5). SORTING AND SIZING Citrus are graded by size. This can be done by hand or by machine. If the grower is grading citrus manually, it is best not to judge the size only by eye, but to use some kind of measuring device. A simple way to check fruit size is to cut a series of round holes in a thin wooden board or a piece of thick cardboard, according to standard market sizes for that variety Citrus are graded by size. This can be done by hand or by machine. If the grower is grading citrus manually, it is best not to judge the size only by eye, but to use some kind of measuring device. A simple way to check fruit size is to cut a series of round holes in a thin wooden board or a piece of thick cardboard, according to standard market sizes for that variety (Figure 6). A revolving drum type machine is often used by packinghouse (Figure 7). Other low-cost grading machines are also available (Figure 8). Fruits are then sized in to progressively larger size classifications as defined by the grade standard. PACKING Sized and graded fruits are conveyed to automatic fillers. The other hand, products are packed by hand in the proper orders. Fruits are jumble-packed into fibreboard containers until they are filled to the designated net weight (5-10 kg). Filled containers are conveyed through automatic labeling wheels which stamp the size on the carton (Figure 9).
STORAGE CONDITIONS Plastic crates or boxes are used for storing fruit. Sweet oranges such as Valencia should be stored with three or four layers per box. Too many layers in one box may cause bruising of the fruit. Boxes should be stacked inside the storage room in a way that maintains good ventilation. For the first few weeks of storage, ventilation windows should be left open. Throughout the storage period, the windows should be left open at night or in cold weather, in order to cool the fruit. When temperatures are high in the day time, the ventilation windows should be closed. Sunlight should not be able to penetrate inside the storage room. Any rotting fruit that are found should be removed. Storage rooms should be constructed in places where cold air can flow into the room at night. The storage room should have a high roof, to allow better circulation of cold air at night. Ventilation windows should be small but there should be a large number of them, to allow better air circulation. It is recommended to that some ventilation pipes should be buried under ground, to bring in cool air through the floor of the room. The roof and walls should have good heat insulation, to keep temperatures as cool as possible. The storage room should be insect-proof and rat-proof. A good storage room is the key for extending the shelf life while maintaining fruit quality. The room should be kept clean, and all rotting fruits should be removed. Before storage, the room should be sanitized by washing the walls and floor with 5% formalin. Optimum temprature is 3-8 C (38-46 F) for up to 3 months, depending on cultivar, maturity-ripeness stage at harvest and production area. Some grown cultivars can be kept at 0-1 C (32-34 F). Valencia oranges should be kept at 9 C (48 F) and optimum relative humidity is 90-95%. CONCLUSION Post harvest operations are playing an important role on products quality and producers benefit. Therefore process of dumping, cleaning, packing, sorting etc. should be done properly regarding the customers needs to minimize the price losses. These facilities also educate the producers to grow their plants more efficiently and raise the quality. Because quality of products raises the market share of that country on global markets LITERATURE CITED Alan, R. ve Padem, H. 1993. Sebzelerde paketleme ss. 208. Verimlilik, Milli Prodüktivite Merkezi Yay, 1993/2, Ankara. Dokuzo uz, M. 1968. Meyvelerde Hasat, Tasnif, Ambalaj, Muhafaza ve Nakil. pp.165. Claypool L. Lawrenceden Türkçeye Çeviri. Ege Üniversitesi Ziraat Fakültesi Yay nlar No: 10, zmir.
llez, S.A. 2001. Ambalaj n ticari hayata etkileri. Antalya Ticaret ve Sanayi Odas Yay nlar, Say : 162, 6-9. TUIK, 2009. Türkiye istatistik kurumu. Figure 1. Dumper conveyor
Figure 2. Orange washing conveyor Figure 3a. Chest tipping cage point
Figure 3b. Brush feeder Figure 4. Orange waxing
Figure 5. Drying conveyor Figure 6. Board with Holes to Check Diameter of Fruit for Grading Figure 7. Sorting of oranges
Figure 8. Other type sorting of oranges Figure 9. Packing of orange