PAKISTAN has a variety of climates. However from the fruit growing point of view, the land can be divided as comprising of warm and cold climate areas. Fruits like, citrus, mangoes , melons etc are grown in the warm plains of Punjab and Sindh, while fruits such as apples, plums, apricots etc. are grown in three cold climate distinct regions; Quetta valley, Swat valley and Gilgit Baltistan.
Fruit is considered an essential diet part by the nutritionists but in Pakistan it is more like a luxury. Major fruit consumption therefore is in large cities. Fresh fruit markets are mainly, Karachi, Lahore, Peshawar and Quetta. Fruit processing plants for juices, jams and jellies are also located close to these consumption areas. Most of the fresh fruit is transported by road from Quetta to Karachi or Lahore over a distance of nearly 1,000 KMs. Fruit from Swat area is also transported by road to Peshawar (100 KMs) or Lahore (700 KMs). These roads are all-weather high ways where large size trucks operate the year round. The maximum travelling time is generally less than 24 hours.
In case of Gilgit Baltistan, the nearest large city is Rawalpindi and the road distance is nearly 600 KMs. The distance between Gilgit and Lahore or Peshawar is nearly 1,000 KMs. The stretch of road between Gilgit and Hasan Abdal (Karakoram Highway) is all hilly with steep gradients and sharp turns. It is often blocked by flash floods and landslides, for days and sometimes for weeks. The transportation cost is therefore very high and only a limited quantity of fresh fruit is transported to markets in Lahore or Peshawar. The situation may change when the Korakaram Highway is upgraded to an all-weather highway.
Under these conditions one of the options available is to process the fruit at location to increase its shelf life and to add to its value, so that it may be transported for long a period over a great distance economically.
Following are the options for value addition of fruits:
Export by Air:
Fresh fruits and vegetables are being exported from Pakistan to Arabian Gulf and Europe, up to USA (Mangoes are being marketed in USA and Japan.) For this purpose, good quality fruit is washed, graded, disinfected and packed in export quality packaging. It is then air lifted from Pakistan’s international airports.
Can this be done for fruit from Gigit Baltistan? Apparent drawback is lack of facilities, such as non availability of cold storage for short term storage of fruit and of export quality packaging material. Quality control for grading and facilities for washing and disinfection also need to be developed. Even if these facilities are created at Gilgit, the biggest problem shall remain uncertain flight schedule, due to weather conditions. This problem shall be resolved only when Gilgit airport is upgraded into an all-weather international airport.
Processing for Juices, Jams and Jellies:
At cottage level, fruits can be processed into juices, jams and jellies with little investment. However, the quality of products is difficult to ensure in case of cottage industries. Generally cottage level manufactured products are consumed locally or sold to tourists. Apparently there is not a large size local market for such products. For marketing purposes, these products must be transported to the nearest population centers in central Punjab. Though juices, jams and jellies increase the value of end product, there are a few limitations in processing fruits in large size installations. The quantity of fruit in the processed product varies between 10 to 50 per cent. The rest are sugar, water and thickening agents. These ingredients are not produced locally and must be transported from nearest market at Lahore. Similarly, the packaging material is either glass bottles or tetra pack that is not produced locally.
For running a fruit processing facility, electric power, steam and skilled man power is also required. The processing facilities shall also be transported from technically developed areas of the country. Thus processing of fruit at Gilgit and transporting the finished products to markets in central Punjab or Karachi would be uneconomical.
On-site Fruit Pulp Manufacturing:
Most fruits are first turned into pulp and then processed for jam, jelly or juice. By turning fruit into pulp, there is a net reduction in weight and volume. Fruit pulp can be transported over long distance if it is refrigerated or sterilized before transport. Fruit pulp is a semi finished industrial product which can be sold to fruit processors only. Large size fruit processors can be asked to study the feasibility of manufacturing and transporting fruit pulp from Gilgit Baltistan.
Most fresh fruits contain more than 85 per cent water. By drying, a part of this water is removed. By this, not only the weight of the fruit is decreased considerably but its shelf life is also increased. Fruit preservation by dehydration is being practiced for the past many centuries. Dehydrated fruit has been discovered in the caves of pre historic people. Fruit can be dehydrated by passing hot dry air (40-60 oC) for a number of hours, over prepared fruit (cut or whole depending on size, washed, disinfected, blanched, etc.) placed in a single layer in an enclosure. Dates are probably the most common dried fruit consumed locally. Since dates are cultivated in hot dry climate, they are generally dried in the open but under shade to slow down the drying process. Quality dates are however dried by hot air under controlled conditions in processing plants.
Grapes, Apricots, Plums, Figs and Mulberry are some of the fruits grown in cold climate and traded in fresh as well as dried form, in Pakistan and neighboring countries. On drying, a good part of the water present in the fresh fruit is removed and the weight of the end product may reduce between 30 to 50 per cent of the original weight. This increases the cost of the dried fruit three to five times without compromising its nutritional value. The increase in shelf life means that it can be safely stored and transported over long distance.
Apparently, the most economical method of fruit drying is by sun. However it is feasible when the sunshine is available and at the right time and for sufficient duration. Most of the fruit grown in Gilgit Baltistan ripens at the end of summer and the start of rainy season. Evidently this is not the ideal climate for sun drying of fruits. Even when the day is sunny and cloudless, the night temperature falls rapidly, resulting in dew and even frost. Any fruit left out in the open is thus damaged.
As already stated, drying needs hot air moving to evaporate the moisture from the fruit and to take it away. The fruit drying does not require high temperature as optimum drying temperature is between 50 to 60 oC. Most of the thermal energy is required to provide the latent heat of evaporation of water, which is nearly 550 K Cal per Kg of water. The requisite for fruit drying is warm air and not sun shine. This makes fruit drying independent of weather conditions. The fruit can be isolated from environment and heated by warm air to dry it. This warm air can be generated by sun shine, by fossil fuel or even by electricity, whichever is economical. Electricity from micro hydel power plants may be considered.
Solar heating is free, where it is available in abundance as it requires lot of investment to capture it. On a bright sunny day, the solar energy available is nearly 6 Kilo watt hours per square meter per day (20,000 BTUs). That much heat can be produced by burning one Kg of coal or 2 Kg of wood. Fruit left in the open to dry is left at the mercy of weather. It takes days to dry. It is often infected by insects or contaminated by dust and has poor quality control. On the other hand food placed on trays in a closed box and dried by warm air dries in hours, has uniform quality which is easy to control and is free from infection or dust.
Air drying can be carried out round the year and at night as well. Hot air dryers consist of two parts, air heater and dying chamber. The air is circulated between the two chambers by an electric fan or blower. Air can be heated by solar air heaters during the warm sunny days. When there is no sun or the air can be heated by fossil fuel in the same system. This results in an economical and efficient system producing good quality dried fruit at a relatively short period. The quality of the end product is easily controlled as it is no more weather dependent. The little sunshine available can also be economically utilized.
Dried, Candied Fruit:
Dried fruit is dipped in sugar syrup and dried again. The sugar forms a thin coating on the dried fruit which increases its taste. Fruits which are low in sugar such as citrus fruits mangoes and bananas etc are popular in Middle East and Europe in candied form.