Hey fellow group members, i've found a link about GM crop that might be useful because it's localised. The gmac stands for Genetic Modification Advisory Committee, Singapore. Therefore they have useful articles on ethical or viable issues of gm crops according to the Singapore's context.
Here's the link
http://www.gmac.gov.sg/
Monday, June 30, 2008
Wednesday, June 25, 2008
Corn starch process
I've summarised the industrial process of making corn starch. This is a uphill task for me because of the numerous technical terms that i have to grasp. I had no choice but to google for these term, hoping that i can come up with alternative terms. So here it is
CLEANING
The corn has to go through a process called wet milling, the first step is to wash the corns twice. And at the same time, removing foreign particles and unwanted parts of the corn.
STEEPING
The corn is next soaked into large tanks of hot water for up to 50 hours. This step is for fermentation of the corn, sulphur dioxide is added at 1000ppm~2000ppm to control the fermentation. Steeping into sulphur dioxide enhances the fermentation because it inhibits unwanted micro organism while not affecting those that are required for fermentation.
STEEPWATER EVAPORATION
The water is drained and the kernels are dried by an evaporator. The steep water is recycled by making a concentrated fermentation liquid.
SO2 PLANT
Sulphuric acid is used for controlling microbial activities as well as to soften the corn kernels.
GERM SEPARATION
Next, the kernels are broken up by a mill and water is added to facilitate milling, this process forms a slurry. The germs should be released from the kernels without any damage to ensure none of the oil escapes.
The germs are separated from the slurry by a centrifuge and hydrocyclones. The germs are then washed and screened to remove any starch. The rest of the slurry are dried for further processing.
GERM DRYING
The water on the surface of the germs are removed by a tapered screw press. The semi-dried germs are then dried to approximately 4% moisture. Remaining fibre are removed and transported for storage.
FINE GRINDING AND SCREENING
After removing the germs, the dried slurry is then grounded to release starch and gluten from the endosperm. It goes through a fibre washing system to remove the starch and gluten. The product of this process is crude starch milk.
STARCH AND GLUTEN PRIMARY SEPARATION
The crude starch milk comprises of starch, gluten and other soluble. It’s processed by a safety strainer and de-gritting cyclone. Due to the different density of gluten and starch, centrifugal force can be used to separate them. Gluten enters the overflow while starch, the underflow.
STARCH REFINING
The crude starch milk is refined by washing with fresh water. By using strong hydroclones and centrifudge, the starch settles quickly. Again, this process can happen because of the different density of water, fibre and starch.
Impurities that are present together with the extracted starch are removed by sieve. This is the only known way to remove impurities from this last stage.
STARCH DEWATERING.
The extracted starch is then dewatered by passing through a peeler centrigudge. After this process, it is discharged to the moist starch hopper.
STARCH DRYING
From the hopper, the starch is fed into a flash dryer to dry in hot air. The dried starch with moisture of 12~13% is then sent for storage.[1]
[1]gmo corn - Google Search
http://home3.inet.tele.dk/starch/isi/starch/tm18www-corn.htm [accessed 25/6/08]
CLEANING
The corn has to go through a process called wet milling, the first step is to wash the corns twice. And at the same time, removing foreign particles and unwanted parts of the corn.
STEEPING
The corn is next soaked into large tanks of hot water for up to 50 hours. This step is for fermentation of the corn, sulphur dioxide is added at 1000ppm~2000ppm to control the fermentation. Steeping into sulphur dioxide enhances the fermentation because it inhibits unwanted micro organism while not affecting those that are required for fermentation.
STEEPWATER EVAPORATION
The water is drained and the kernels are dried by an evaporator. The steep water is recycled by making a concentrated fermentation liquid.
SO2 PLANT
Sulphuric acid is used for controlling microbial activities as well as to soften the corn kernels.
GERM SEPARATION
Next, the kernels are broken up by a mill and water is added to facilitate milling, this process forms a slurry. The germs should be released from the kernels without any damage to ensure none of the oil escapes.
The germs are separated from the slurry by a centrifuge and hydrocyclones. The germs are then washed and screened to remove any starch. The rest of the slurry are dried for further processing.
GERM DRYING
The water on the surface of the germs are removed by a tapered screw press. The semi-dried germs are then dried to approximately 4% moisture. Remaining fibre are removed and transported for storage.
FINE GRINDING AND SCREENING
After removing the germs, the dried slurry is then grounded to release starch and gluten from the endosperm. It goes through a fibre washing system to remove the starch and gluten. The product of this process is crude starch milk.
STARCH AND GLUTEN PRIMARY SEPARATION
The crude starch milk comprises of starch, gluten and other soluble. It’s processed by a safety strainer and de-gritting cyclone. Due to the different density of gluten and starch, centrifugal force can be used to separate them. Gluten enters the overflow while starch, the underflow.
STARCH REFINING
The crude starch milk is refined by washing with fresh water. By using strong hydroclones and centrifudge, the starch settles quickly. Again, this process can happen because of the different density of water, fibre and starch.
Impurities that are present together with the extracted starch are removed by sieve. This is the only known way to remove impurities from this last stage.
STARCH DEWATERING.
The extracted starch is then dewatered by passing through a peeler centrigudge. After this process, it is discharged to the moist starch hopper.
STARCH DRYING
From the hopper, the starch is fed into a flash dryer to dry in hot air. The dried starch with moisture of 12~13% is then sent for storage.[1]
[1]gmo corn - Google Search
http://home3.inet.tele.dk/starch/isi/starch/tm18www-corn.htm [accessed 25/6/08]
Friday, June 20, 2008
Common crops that are genetically modified
I've found a list of crops that are commonly modified, the table is shown as below
Taken from http://biotech.cas.psu.edu/articles/gmo_crops.htm (20/6/08)
Since my group will be doing on genetically modified corn starch, i have research more in depth into corn. Upon my research, i've found that Non-Gmo corn starch are 5% more expensive that gmo corn.[1] This is expected as GMO crops are made for higher yield and so the reduction in prices will follow. Consumers will not mind paying the premium for non-gmo corn products if they are concerned about ethical or health issues that are associated with GMO products.
There are articles that show that genetically modified crops are nutritionally same as non genetically modified crops. The animals are also not affected by the introduction of GMO-crops into their diets. However, in my opinion, this article is biased as it is linked to biotechnology institutions. [2]
[1]http://sg.news.yahoo.com/rtrs/20080701/tbs-korea-corn-gmo-b8dd11d.html
What is gmo crops?
Basically, gmo crops stands for Genetically modified organism, GMO crops indicates that the crops have been modified genetically for specific purposes. The seeds of these crops are taken to a laboratory to conduct a series of test to modify their genetic make up. The modified crops can have delayed ripening, example of these are tomatoes. But the main purpose of genetically modifying crops is to increase crop yield. To acheive this effect, several ways to modify the crops genetic make up is used. These includes, resistant to drought, resistant to pest, enhanced growth rate or even resistant to viral infections. Another purpose is to increase vitamin in the crops or to add vitamins that never existed in the original crops
An astonishing fact is that in the United states, 60% of the food supplies inside the supermarket contains ingredient that is derived from GMO crops. That means that majority of the food have ingredients that are genetically modified. [1]
GMO Crops - Biotechnology Food & Agriculture
http://biotech.cas.psu.edu/articles/gmo_crops.htm (accessed 20/6/08)
An astonishing fact is that in the United states, 60% of the food supplies inside the supermarket contains ingredient that is derived from GMO crops. That means that majority of the food have ingredients that are genetically modified. [1]
GMO Crops - Biotechnology Food & Agriculture
http://biotech.cas.psu.edu/articles/gmo_crops.htm (accessed 20/6/08)
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