Frozen Fruits and Vegetables Frozen fruits and vegetables are highly perishable unless  properly  stored.    Upon delivery, they must be transferred  promptly  to  a  low-temperature  storage space. Check the temperature of the load upon arrival by taking temperature readings of cartons selected from top layers inside of shipping cases. When the temperature is found to be higher than that of  the  freezer  room,  scatter  the  shipping  cases  loosely about the room on hand trucks or on the deck with adequate space between individual cases to permit rapid lowering of the product temperature to the freezer room temperature. Use of a portable fan to create an air current  over  the  items  will  speed  up  temperature equalization. When  the  temperature  of  the  items  has been lowered sufficiently, stack the cases compactly at once. Stack from the bulkhead toward the center of the room, starting about 4 inches from the bulkhead or bulkhead coils. Stack the cases on pallets to permit the circulation of air under them. The use of pallets will also improve  the  sanitary  conditions.  In  rooms  where  cold air is expelled directly from blower units at the ends of the rooms, the cases should be stacked low enough to permit air circulation. Allow at least 2 feet between the top of the stack and the overhead or air ducts. Dairy Products and Eggs Keep the cold storage room for dairy products and eggs fresh by keeping it clean and by circulating the air slowly. Air circulation can be increased by the use of pallets or deck gratings and by the proper stacking of the various  lots. REFRIGERATION UNITS Three factors affect the rate at which frost and ice accumulate on refrigerator coils: (1) door traffic, (2) excessive temperature difference between the coils and the box, and (3) moisture from the stored materials. In each  case  the  buildup  can  be  reduced  by  properly planned  and  executed  breakout  procedures.  Measures discussed  in  the  following  paragraphs  may  be  used  to prevent  excessive  icing  of  coils. Door Traffic Breakouts  should  be  planned  for  a  full  day’s requirements.  All  messes  must  draw  their  frozen subsistence items at a predetermined time, usually in the morning.  Any breakout  from items withdrawn at this single daily the  freeze  box,  if  not  intended  for immediate use, should be stored temporarily in the chill box. This  one  breakout  per  day  should  be  strictly enforced. With a little planning on the part of the various messes, it should not be too difficult. In this way, the reefer temperature will remain constant and excessive icing  from  too  much  door  traffic  will  be  kept  to  a minimum. Temperature  Controls A difference in the temperature of the refrigerated spaces and the refrigeration coils will cause vapor to form on the coils and the refrigeration coils will turn the vapor  into  ice.   This ice formation continues until the temperatures of the coils and the refrigerated spaces equalize. The temperatures of the coils and the refrigerated spaces are likely to differ most during the period when the   freeze   box   is   being   restocked.   The   higher temperature of the food items being stored will cause a rise in temperature in the refrigerated space and produce vapors. There is no way to prevent this condition, since the  work  of  storing  must  go  on.  However,  once  the storage has been completed, the box should remain closed until the normal temperature level of the freeze box has been reached. Air Circulation Proper storage and adequate air circulation help prevent   excessive   ice   formation.   Continuous circulation by electric blowers is necessary at all times. Storage  arrangements  should  allow  free  circulation  of air throughout the box. Adequate  aisles  and  overhead  space  should  be provided  to  permit  the  free  circulation  of  air  from  the blowers.  Blowers  should  be  inspected  each  day  to ensure  proper  operation. Any  malfunction  in  the circulating unit should be reported to the duty engineer immediately. Defrosting  and  Cleaning  Refrigerators The refrigeration coils and units in cold storage spaces should be defrosted as often as possible. A layer of frost or ice 1/4 or more inches thick will reduce the efficiency of the refrigeration system and may result in overloading  the  compressors. Always  consult  the engineering  department  regarding  the  defrosting  of  the refrigeration  system. 2-13