Physical properties of foods are very crucial in product development, process design, shelf life and quality. Knowledge of physical properties is important in handling, preparing, processing, preserving, packaging, storing and distribution of foods. Let's find some examples to demonstrate the application.
Watch the following videos. In your wiki page, explain the principles of fruit sorting equipment. What are the physical properties being utilized in the sorting operation?

After i watch the video of sorting fruits,i still don't get any ideas how this process relate to physical properties of food.What i can see roughly is,"machinery works there and here".But then,I realize,this is what Prof Karim want,observing,thinking and understand more.How???yes,continue learning.Thanks prof!!!=) after reading,googling,and etc,this what i can write about application of physical properties of food in sorting process of fruits.

We start with harvesting and handling the fruits.After harvest,we can not improved the quality,but only can maintain it.Thus,how we handle the fruits after harvesting are very important.Harvested fruits should be kept shaded and handle it gently.If not,it may cause bruises and other mechanical damage.Bruises and other mechanical damage not only affect appearance, but provide entrance to decay organisms as well.
Besides,mechanical damage also increases moisture loss. The rate of moisture loss may be increased by as much as 400 percent by a single bad bruise on an apple, and skinned potatoes may lose three to four times as much weight as non-skinned potatoes. Damage can be prevented by training harvest labor to handle the crop gently; harvesting at proper maturity; harvesting dry whenever possible; handling each fruit or vegetable no more than necessary (field pack if possible); installing padding inside bulk bins; and avoiding over- or under-packing of containers.

For preparing the fruits,storage condition and how to packaging this post harvest fruits are very important.Packaging should be designed to prevent physical damage to produce, and be easy to handle.Storing condition is the most important parts as we know organic living continue respirate.This respiration generates heat as sugars, fats, and proteins in the cells of the crop are oxidized. The loss of these stored food reserves through respiration means decreased food value, loss of flavor, loss of salable weight, and more rapid deterioration. The respiration rate of a product strongly determines its transit and postharvest life. The higher the storage temperature, the higher the respiration rate will be.
Hence,sorting equipment were designated to sort the fruits by its quality.How?as we can see from the video,the fruits are sort according to their weight.As i have explain,if the fruits have been damage during handling/packaging/storing,the weight is slightly lighter.Less weight means low quality.Amazing right?with the knowledge of physical properties of food,we can sort the fruits.Not the fruits,the quality=)
p/s:make sure the price of the low quality fruits lower once u have your own factory!!!(^^,)