FOOD PROCESSING
Name: Mr Dev
Abrasion Peeling
Description of process:
In abrasion peeling, the material to be peeled is fed onto carborundum rollers or fed into a rotating bowl, which is then lined with carborundum. The abrasive carborundum surface removes the skin, which is then washed away with a copious supply of water. The process is normally carried out at ambient temperature.
Advantages:
This process results in reduced energy consumption, while the peel can be recovered and used as animal feed. In this case, energy is not required for heating water or producing steam.
Disadvantages: But there is a needed for the operation of the rollers or rotating bowl. Still, large quantities of water are consumed. There is a high product loss and high production of waste water. The use of abrasion peeling can affect the hygiene quality of the product, since no peeling water is added, the cooling function of water is not fulfilled and there can be localised high temperatures.
Examples:
This technique is used for peeling onions, potatoes, carrots and beets, as the skin is easily removed and the quality of the product can be maintained. Sometimes abrasion peeling is used as a pre-peeling step before knife peeling.
Alternative:
The capital and energy costs of the process are low, but steam peeling is reported to be more economical.
Sort by size (fixed aperture screen)
Foods that are meant to be cooked/heated are sorted by size. For example, potatoes are sorted by size.
The reason potatoes are sorted by size is to get a uniform size for the potatoes product. It is to get a uniform quality for every product. Moreover, potatoes that are to be heated/cooked tend to have smaller size, as the size of it affects heat transfer in the potatoes. Different types of screen are used for size separation. Fixed aperture screens of flat-bed type are used in preliminary sorting potatoes.
Flatbed screen
How it works
Normally, rice and corn are treated
Abrasion Peeling
Description of process:
In abrasion peeling, the material to be peeled is fed onto carborundum rollers or fed into a rotating bowl, which is then lined with carborundum. The abrasive carborundum surface removes the skin, which is then washed away with a copious supply of water. The process is normally carried out at ambient temperature.
Advantages:
This process results in reduced energy consumption, while the peel can be recovered and used as animal feed. In this case, energy is not required for heating water or producing steam.
Disadvantages: But there is a needed for the operation of the rollers or rotating bowl. Still, large quantities of water are consumed. There is a high product loss and high production of waste water. The use of abrasion peeling can affect the hygiene quality of the product, since no peeling water is added, the cooling function of water is not fulfilled and there can be localised high temperatures.
Examples:
This technique is used for peeling onions, potatoes, carrots and beets, as the skin is easily removed and the quality of the product can be maintained. Sometimes abrasion peeling is used as a pre-peeling step before knife peeling.
Alternative:
The capital and energy costs of the process are low, but steam peeling is reported to be more economical.
Sort by size (fixed aperture screen)
Foods that are meant to be cooked/heated are sorted by size. For example, potatoes are sorted by size.
The reason potatoes are sorted by size is to get a uniform size for the potatoes product. It is to get a uniform quality for every product. Moreover, potatoes that are to be heated/cooked tend to have smaller size, as the size of it affects heat transfer in the potatoes. Different types of screen are used for size separation. Fixed aperture screens of flat-bed type are used in preliminary sorting potatoes.
Flatbed screen
How it works
Normally, rice and corn are treated
References: Drying of high moisture paddy [online]. Available from: http://www.fao.org/docrep/x5427e/x5427e0d.htm [Accessed: 16th November 2013] Flat –bed Dryers---a drying machine of rice seed to multi purposes [online]. Available from: http://lift-fund.net/downloads/ANNEX%20III%20Technical%20Fact-Sheet%20of%20Radanar%20Ayar 's%20Model%20Multi-Purposed%20Flat%20Bed%20Dryer.pdf [Accessed: 16th November 2013] Google Books. 2013. FOOD PROCESSING AND PRESERVATION. [online] Available at: http://books.google.com.sg/books?id=tbxGHBUY0BcC&pg=PA173&lpg=PA173&dq=size+sorting+food+process&source=bl&ots=zA1dHbXMFz&sig=TEK5viPRFQyDQjxS20a8U_-wMro&hl=en&sa=X&ei=kDaHUr3sJIeQrgfPsIGQCw&ved=0CB8Q6AEwAA [Accessed: 15 Nov 2013]. Wiki-ze.elas-calculator.eu. 2013. Peeling in food industry - Efficiency Finder. [online] Available at: http://wiki-ze.elas-calculator.eu/index.php/Peeling_in_food_industry [Accessed: 14 Nov 2013]. Google Books. 2013. FOOD PROCESSING AND PRESERVATION. [online] Available at: http://books.google.com.sg/books?id=tbxGHBUY0BcC&pg=PA171&lpg=PA171&dq=wet+cleaning+food+process&source=bl&ots=zA1dG50PGC&sig=WlSUp-MhO9Pvm-BiVRYo9dWobPA&hl=en&sa=X&ei=UtqEUuGUI4KTrge77oGgAQ&ved=0CCgQ6AEwAA#v=onepage&q=wet%20cleaning%20food%20process&f=false [Accessed: 17 Nov 2013].