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Description: General - All varieties of fresh agricultural produce are subject to some loss in weight in course of transit from the area of production to the center of consumption. This loss is partly due to respiration, the cells of the fruit transported continuing to live and to produce carbon dioxide. Water is also lost by transpiration. Such normal phenomena may sometimes be accompanied by other types of damage - rotting - damage by parasites - etc. Normal loss in weight Such loss depends upon: the nature of the product; its water content; the mode of preparation (or conditioning) and packing; and the conditions of transport. For any given product, the loss in weight may vary according to: the time taken in transport; temperature (and variations of temperature) the water vapor content of the surrounding atmosphere; the degree of agitation of the surrounding atmosphere. The influence of temperature is by far the predominant factor in the rate of desiccation. For instance, in the case of wheat kept for five months in a dry atmosphere, the loss by desiccation approximates: at 16 C. - 0.4% at 27 C. - 1.5% at 37 C. - 2.8% at 44 C. - 4.5% The second factor of importance is the water content of the product. Under the conditions of the above example, but at a temperature of 18 degrees C - Wheat: containing 9% of water loses approx. 0.0% containing 12% of water loses approx. 0.03% containing 14% of water loses approx. 0.64% containing 20% of water loses approx. 1.2% This example shows that an agricultural product will easily lose any water contained in excess of its normal water content. (Note: The above examples do not take into account any continuous renewal of the surrounding atmosphere - naturally by wind or artificially by electric fans - which would accelerate the process of desiccation to a considerable extent.) Most fruit and vegetables lose water. The longer the product is stored, the more the rate of desiccation diminishes. Normal losses in weight (by desiccation) experienced on certain shipments to London of Moroccan fresh fruit and vegetables (time in transit five to six days) resulted in the following: New potatoes - Lose 1 to 2.5% - a basket of 26 kilos net (57.32 lb.) would only weigh about 56 lb. Oranges - Loss 2 to 3.3% - a Californian or Florida case of 30 kilos would lose 1 kilo (i.e. 66 lb. would become on arrival 64 lb. only) Tomatoes - Loss 1 to 4.75% - a package of 10 kilos (i.e. 22 lb.) would have to be sold on the basis of 21 lb. on arrival. These figures are for illustrative purposes only. Potatoes - New potatoes lose water fairly rapidly. Sprouting of potatoes greatly increases the loss of water. Tomatoes - Tomatoes picked and shipped rapidly may arrive at destination with very little, or in some cases, no appreciable loss in weight. Breakdown (whether external or internal) Causes: 1) When goods have been packed in an unsatisfactory condition. e.g., dampness of certain goods, or over-ripeness of some fruits. 2) When the mode of packing is defective, e.g. containers airtight. Other examples of defective packing: bad quality fiber lining (damp, etc.) - use of damp saw dust (noticed where citrus fruits have been conditioned with Spanish type machine and then insufficiently dried and brushed). 3) When the packages have been stowed in ship's hold without provision having been made (by leaving free spaces) for the adequate circulation of air. 4) Where ship's hold has been closed so completely as to be practically airtight, or when the ship's ventilation system is at fault. 5) Where the produce has been carried at too low or high temperature. 6) Where produce has been inadvertently frozen.
Index: 753
Commodity Name: VEGETABLES AND FRUIT (Fresh)

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