NEED TO IMPROVE FRUIT PROCESSING
Ahsan Ramzan, Dr. Zaid Mustafa, M. Imran Lodhi
Pakistan is among top list of developing countries. Fruit production is growing every year and its export is also growing but sometime during glut season its supply becomes surplus than its direct consumption. So, to avoid its wastage, its processing becomes inevitable. Fruit processing is the preparation of fruit for indirect human consumption. In past fruits were dried and there were no peeling or special treatment. So, the preserved fruits were facing fermentation and insect attack etc. Now a day, different fruit processing steps were taken to control micro-organism, fermentation, increase the shelf life and to control the insect attack. The importance of fruit processing is to increase the shelf life of fruit product. To protect from mold, fermentation and insect control. To develop new valuable product e.g. jelly, jam, pickles and juices etc. We preserve fruits for using during off season. This process reduces fruit losses.
Horticultural commodities are perishable. In our country storage conditions are so poor. Limited storage capacity and continuous supply of electricity is challenge. So, it is necessary effort to process fruits and vegetables. In our country there are lot of fruit processing plants. “Naveed Fruit Processing Plant” is a processing company where fruits are sorted, graded and packed. It is located in Sakardu district of Baltistan. Mitchell’s and Shezan processing company in Lahore and Karachi, food processing industry D.G Khan, Rahman and Ahmad Processing Industry in Lahore and Karachi, respectively.
In fruit processing flow chain, fruit harvesting is first step followed by packing in plastic trays, transportation to processing unit, pre-cooling, cleaning, washing, sorting, grading, peeling, removal of inedible constituent, size reduction, mixing, filtration and prevention of enzymatic browning. Fruit harvesting is the main step to check the fruit that are harvested at correct maturity. Fruits should be harvested by cutting the stem 1-2 cm away from the fruit so that fruit may not damage. Fruits are packed in plastic trays after harvesting. The fruits can normally be placed directly into the crate. The crate should not comprise more than three layers of fruits. If possible, the fruits in the crate should be left under the tree until taken to the processing unit. The harvested fruit packed in trays or crate and then the crate is loaded in the vehicle and reached to the processing units. Pre-cooling is done to remove field heat from the fruit. It is important to remove the field heat as soon as possible. The heat reduction process is often carried at the time of cleaning on the farm with water. Field heat removal can also be done in cold stores. After cooling the fruits, washing is done. Two types of cleaning are practiced, wet cleaning and dry cleaning. In washing fruit is washed in a large container which is full of water and the fruit wash and then fruit is dried on the conveyor belts. After drying sizing and grading process start. Sorting is the separation of raw material into categories of different physical characteristics such as weight, size, shape and color. While grading is separation into categories by quality. In food industry, where huge quantity of raw material is handled by machine, sorting and grading form an essential part of processing. Weight sorter are machine that weigh the individual item and separate into various categories. Size sorting is important for an effective use of processing machinery. Grading based on shape is not very common except for removal of contamination from the raw material. Color sorting is important where uniformity of color fetch a higher price of the product. Nature protects food crops from the attack of external forces by providing a protective covering. This covering is known as peel, shell or husk depending on the raw material, is often inedible and must be removed. Peeling knife and mechanical peeler is used for peeling purpose. Apple, carrot and potatoes are peeled by mechanical peeler. Fruit like pineapple have central core, which although edible in some cases must be removed during processing. Removal of core is called coring, dates and plum have pits or seeds located centrally in them. The removal of these seeds is called pitting. Removal of stem is called stemming, usually done by hand e.g., strawberries and tomatoes. Size reduction is an important operation in industry, as a definite size may be demand of consumer. It may help in the extraction of desirable constituent from the raw materials e.g. crushing fruits from juice. In tomatoes the shelf life is less so the product of tomatoes is making tomato ketchup whereas, potatoes are used to making various products e.g. lays, chips etc. oranges are used to making various products e.g. juices, jams, tangs etc. Unripe mango, olive and lime are used for pickling.
Mixing is an operation in which uniform combination of two or more substances take place. Two components in mixture may be solid or liquid. In certain plants foods enzymes are used for discoloration, especially after these have been peeled or injured. These enzymes catalyze the oxidative polymerization of polyphenolic substrates contained in the food. The polymerized product of this complex reaction give rise to browning as observed on the surface of cut potatoes, apples and banana etc. Change in color is prevented by mild heat treatment or by using certain chemicals. Sulphiting agents, such as sulphur dioxide and salts releasing gases (Na-or-K-metabisulphite) are highly effective in controlling enzymatic browning. Ascorbic acid is the best-known alternate to sulphites. It is effective to control enzymatic browning.
Mango is the second major fruit crop of Pakistan after citrus and is ranked fourth in the world for its production. Mangoes are harvested and conveyed to the processing units. Mangoes are washed and dried on the conveyor belt and then sizing and grading of the mangoes are carried out after sizing and grading mangoes are sorted on conveyor belt by sizing, coloring and quality etc. After sorting, packing starts. The packer only packs one size of mango fruit in each carton. Mangoes are packed into the cartons by counting. There may be 12, 16, 20 number of mangoes per carton, depending on the size of mango. After packing mangoes are stored in storage to control temperature and humidity. Mature green mangoes are stored for two weeks. Pakistan exports mangoes to different countries in the world.
Citrus is the first major fruit crop of Pakistan. Citrus fruits are conveyed to processing unit after harvesting with the help of trolley. First step is fruit washing in a large container and drying on conveyor belt after drying sizing and grading of the fruit is made on conveyor belt. After this process, sorting of the citrus by color, size and shape is carried out on conveyor belt. After sorting waxing process starts, in waxing process the outer skin of fruit is polished and made look attractive. Fruit is waxed on conveyor belt, after waxing fruit is dried by air on conveyor belt. After drying the fruit is packed in a box and stored in a store room or loaded in a cooling truck and conveyed to the ship.
Our country has every kind of fruits and vegetables. Our main concern should be to improve quality of produce and make skin of fruits free from every kind of blemishes and damages. We have to make cold storage and CA storage. We should carefully adopt global GAP (good agricultural practices) and ISO situations. With the completion of CPEC (China Pakistan Economic Corridor) project the most benefit will go to the horticultural crops. These crops after harvesting, applying post-harvest treatment will be packed for shifting from one place to another place in a straight forward way. There is dire need to export processed fruit to earn foreign exchange.