Table 11 Chilling methods of solid and liquid foods [94]
From: A review on mechanisms and commercial aspects of food preservation and processing
Solid foods | Batch air chillers | Warm food items are fed into large refrigerated room, widely used in industry |
Moving air | This cost-effective, hygienic, and widely used method incurs little damage to equipment. Surface dehydration of the food is the major disadvantage of this process | |
Ice/ice water chilling | Food items are packed in boxes and then they are placed between layers of crushed ice. Melting ice assists to maintain the temperature at 0 °C. However, this method is not labor efficient and consumes much time comparing to other processes | |
Cryogenic cooling | This method involves the use of liquid nitrogen to freeze the product. Thermal shock confrontation of food items makes this process vulnerable | |
Immersion cooling/hydrocooling | A cost-effective cooling method is suitable for small products. This technique involves immersing or spraying the product in cool water at near 0 °C. Hydrocooling moisturizes food items which can be detrimental to some extents | |
Liquid Foods | Batch cooling of liquids | A jacketed stainless steel vessel of varying capacity with agitator inside is usually used for this type of chilling. The coolant may circulate through the jacket of the vessel or through a coil placed in the liquid food stuff, or both while the agitator incurs uniform heat transfer |
Continuous cooling of liquids | The continuous cooling of liquids can involve multi-plates and tubes, aeration, and double-pipe coolers. The most widespread piece of equipment is the multi-plate cooler, which has the best efficiency, high surface area for exchanging heat, easy cleaning opportunity, and less material requirement than others |