Beautiful + Fair Brinjal/eggplant

Hei hei...take a look on this video before you begin your journey with us to find out the secret of “beautiful + fair” brinjal....

Why does the flesh color of a cut brinjal turn to rust brown after some time?

DO YOU KNOW???It is actually caused by enzymatic browning which occurs in other fruits as well such as apples and pears. Enzymatic browning is one of the most vital problems related to color deterioration in fresh-cut fruits or vegetables. Such phenomenon is caused by the activity of a group of enzymes which is known as polyphenol oxidases as the produce expose to atmosphere. This enzymatic reaction involves the oxidation of phenolic substrates, occurs naturally in many fruits, to o-quinones, which is very reactive. The o-quinones will react with other phenolic compounds, other quinone molecules, and the amino group of proteins, amino acids, peptides. Once tissue is damaged by slicing, cutting or pulping, enzymes liberated from the tissues will come into contact with phenolic compounds. (Yiu H. Hui, József Barta, 2006)

There are many ways to prevent enzymatic browning such as blanching, exclusion of oxygen, use of sugars or salts and lowering pH. (L. R. Verma, V. K. Joshi, 2000) However, there is another traditional way to prevent browning of brinjal according to one of our group member’s mother. According to Shieh Yee’s mother, soaking freshly cut brinjals into water after washing rice can prevent brinjals browning. BELIEVE IT OR NOT???How true is it? What is the scientific theory hidden? We carried out a simple experiment to prove it.

Let the experiment begins.....

Why we carried out this experiment???

The objective of this experiment is to test whether enzymatic browning of brinjal can be prevented by soaking it in the water after washing rice.

What materials we used:

1. Brinjals
2. Rice
3. Water
4. Containers
5. Knife

Ready???go!!!!!!!

1. First of all, one cup of rice is poured into a container and washed with pipe water. The water after washing rice was collected.
2. A brinjal was cut into slices.
3. A few slices of brinjal were placed on a plate at room temperature.

   

4. Another few slices were soaked in the w

   ater after washing rice.

5. After 15 minutes, the appearance and color of brinjals were observed. Comparison was made between brinjal at room temperature and brinjal soaking in water after washing rice.

What we obtained???curious???jom...have a look

The brinjal (eggplant) slices without soaked in rinsed rice water become browning after 15 minutes.

The brinjal (eggplant) slices soaked in rinsed rice water remain white.

Comparison between these brinjals treated with different treatment

Dont know why???dont worry...we tell you why

Rinsed rice water is obtained after the rice is frequently rinsed and washed before the cooking. High B vitamins content (thiamine, riboflavin and niacin) can be found in rinsed rice water because B vitamins are water soluble. (David Franklin n.d.) Niacin (also known as nicotinamide or nicotinic acid) is a component of coenzymes used widely in cellular metabolism, oxidation of fuel molecules, and synthesis of fatty acid and steroid. (Anderson, J. and Young, L. 1998) Enzyme activity can be affected by the presence of acid. Hence nicotinic acid has the ability to prevent brinjal slices from browning. (Tull, A. 1997) In addition, pH of nicotinic acid is much lower than the optimum pH for polyphenol oxidase activity. As a result, it inhibits browning reaction. (Martin et al. 1999) Acid is capable to reduce quinones convert to phenolic compounds before they can undergo further reaction to form pigments. (Emerging Food R&D Report, 2001) Besides that, riboflavin also acts as antioxidants which prevent fat rancidity, destruction vitamin A and C and the browning of food from enzyme. (Encyclopedia Britannica, 2009) Other reagents that usually used to inhibit the enzymatic browning are sodium chlorite, nitric oxide and ascorbic acid. Sodium chlorite is an oxidizing agent that has ability to produce chlorine dioxide gas in an acidic environment. The purpose of lowering of pH is to control the microbial growth. (Lu. S. et al. 2007) While nitric oxide and ascorbic acid are used to promote the modified atmosphere aid to decrease oxygen and increase carbon dioxide to inhibit activity on polyphenol oxidase and microbial growth. (He, Q. et al. 2008)

BELIEVE IT :

The function of rinsed rice water to inhibit enzymatic browning in brinjal (eggplant) has been proven.

Thanks so much!!!!

1. Yiu H. Hui, József Barta, 2006. Handbook of Fruits and Fruit Processing. Australia: Blackwell Publishing, pg 133.
2. L. R. Verma, V. K. Joshi, 2000. Postharvest Technology of Fruits and Vegetables: Handling, Processing, Fermentation and Waste Management. Volume 1: Feneral Concepts and Principles. New Delhi: M.L. Gidwani, Indus Publishing Company, pg 174.
3. David Franklin, n.d. Nutritional properties of rice. [online] National Research Houston, G. O. Kohler Council (U.S). Available from: <http://books.google.com.my/books?id=Y0ArAAAAYAAJ&pg=PA46&lpg=PA46&dq=rinse+rice+water+properties&source=bl&ots=76y2oa-NB2&sig=numPvqDa_qyQ8TBSOEYGNrxj70w&hl=en&ei=SfzNSrzeKYGVkAWnldTtAw&sa=X&oi=book_result&ct=result&resnum=3#v=onepage&q=&f=false> [Accessed 8 October 2009]
4. Anderson, J and Young, L., 1998. Water Soluble Vitamin. [online] Available from: <http://www.ext.colostate.edu/PUBS/FOODNUT/09312.html> [Accessed 8 October 2009]
5. Tull, A., 1997. Food and Nutrition. [online] Available from: <http://books.google.com.my/books?id=N_s6Dn8HC8AC&pg=PA169&lpg=PA169&dq=how+nicotinic+acid+prevent+browning&source=bl&ots=_Z7e23VA4d&sig=9XBjiWdLFS5gAWukZfr1SgdVVf4&hl=en&ei=0ZvQSrfDMIiWkAXswpD5Aw&sa=X&oi=book_result&ct=result&resnum=4&ved=0CBkQ6AEwAw#v=onepage&q=how%20nicotinic%20acid%20prevent%20browning&f=false> [Accessed 10 October 2009]
6. Encyclopedia Britannica, 2009. Vitamin C. [online] Available from: <http://www.britannica.com/EBchecked/topic/631079/vitamin-C#> [Accessed 10 October 2009]
7. Lu. S., Luo, Y., Turner, E., Feng, H., 2007. Efficacy of Sodium Chlorite as an Inhibitor of Enzymatic Browning in Apple Slices. Food Chemistry 104, 824–829.
8. He. Q., Luo, Y., Chen, P. 2008. Elucidation of the Mechanism of Enzymatic Browning Inhibition by Sodium Chlorite. Food Chemistry 110, 847–851.
9. Martin, Stefan, T., Sapers, Gerald, M., Miller, Robert, L., 1999. Process for Inhibiting Enzymatic Browning and Maintaining Textural Quality of Fresh Peeled Potatoes. [online] Available from: <http://www.patentstorm.us/patents/5912034/description.html> [Accessed 10 October 2009]
10. Emerging Food R&D Report, 2001. Seek Alternatives that Inhibit Enzymatic Browning in Fruits and Vegetables. [online] Available from: <http://www.thefreelibrary.com/Seek+alternatives+that+inhibit+enzymatic+browning+in+fruits+and...-a071359876> [Accessed 10 October 2009]