Friday, February 27, 2009

Nasi Kandar




INTRODUCTION:

Nasi Kandar, a popular northern Malaysian dish, is an original meal that originated from Penang. It literally means "rice on the shoulder". From as early as the la19th century, coolies who worked at the port of Penang basically survived on nasi kandar for their lunch. Nasi Kandar has come a long way since. The name has been remained and today the word “Nasi Kandar” is seen on most Tamil Muslim or "Malaysian Mamak" restaurants and Indian-Muslim stall meals. As one of Penang most famous food, we can now find it everywhere around Malaysia. It is no longer plain white rice with a single curry dish but now at a typical restaurant, there are a lot of variety of curry and types of food that being served. Patrons can choose a variety of side dishes that may include curry fish, curry beef, curry chicken, roasted chicken, boiled egg, kacang bendi (lady's fingers/okra), sotong (squid), terong (brinjal/aubergine/egg plant), and fish roe.


NUTRITIONAL VALUES:

Table 1: Nutritional Composition of Nasi Kandar


(NAL, 2009)

• 42% of total energy required daily
• 16.1% of total carbohydrate required daily
• 104.6% of total protein required daily
• 64% of total fat required daily

Total calorie break down for:
1. Carbohydrate: 69.9g x 4 kcal/g = 279.6 kcal
2. Protein: 54.4g x 4 kcal/g = 217.6 kcal
3. Fat: 37.1g x 9 kcal/g = 336.9 kcal


METABOLISMS INVOLVED:

Carbohydrate Metabolism

The main source of carbohydrate in Nasi Kandar comes from rice. Carbohydrates are made up of carbon, hydrogen, and oxygen atoms and they are classified as monosaccharides, disaccharides, and polysaccharides by depending on the number of sugar units that they contain. Carbohydrate metabolism begins with glycolysis, which releases energy from glucose or glycogen to form two molecules of pyruvate in which the pyruvates enter the Krebs cycle, an oxygen-requiring process, through which they are completely oxidized. Before the Krebs cycle can begin, pyruvate loses a carbon dioxide group to form acetyl coenzyme A (acetyl-CoA). This reaction is irreversible and has important metabolic consequences. The conversion of pyruvate to acetyl-CoA requires the B vitamins. The hydrogen in carbohydrate is carried to the electron transport chain, where the energy is conserved in ATP molecules. Metabolism of one molecule of glucose yields 31 molecules of ATP. The energy released from ATP through hydrolysis can then be used for biological work. In the liver and muscles, most of the glucose is changed into glycogen by the process of glycogenesis. Glycogen is stored in the liver and muscles until it is needed when glucose levels are low. If blood glucose levels are low, then epinephrine and glucagon hormones are secreted to stimulate the conversion of glycogen to glucose. This process is called glycogenolysis. (Gita Patel, 2008)


Protein Metabolism

The major source of protein in Nasi Kandar comes from fried chicken and fried squids as seafood is high in protein too. Proteins contain carbon, hydrogen, oxygen, nitrogen, and other atoms such as sulphur. Protein is digested and broken down into amino acids. If amino acids are in excess of the body's biological requirements, they are metabolized to glycogen or fat and subsequently used for energy metabolism. If amino acids are to be used for energy, their carbon skeletons are converted to acetyl-CoA, in which the acetyl-CoA enters the Krebs cycle for oxidation, producing ATP. The final products of protein catabolism include carbon dioxide, water, ATP, urea, and ammonia. Transamination reaction is the reactions that transfer the nitrogen from one keto acid to another keto acid. It converts L-glutamate to form ammonia which is used for the synthesis of urea. Urea is transferred through the blood to the kidneys and excreted in the urine. (Gita Patel, 2008)

Fat Metabolism

The major source of fat in Nasi Kandar comes from fried chicken. Fats contain mostly carbon, hydrogen and oxygen atoms. The three main forms of fat that found in food are triglyceride, the phospholipids, and the sterols. Triglyceride is the form in which the fat is stored for fuel and sterol is commonly referred to cholesterol. The main pathways of fat metabolism are lipolysis, beta-oxidation, ketosis, and lipogenesis. Lipolysis and beta-oxidation occurs in the mitochondria. It is a process in which two carbon atoms are removed from the fatty acid per cycle in the form of acetyl-CoA. The acetyl-CoA will then proceeds through the Krebs cycle to produce ATP, CO2, and water. Ketosis occurs when the rate of formation of ketones by the liver is greater than the ability of tissues to oxidize them. It occurs when large amounts of fat are eaten in the absence of carbohydrate. Lipogenesis occurs in cytosol. It is a process in which the fatty acids are derived from the hydrolysis of fat as well as from the synthesis of acetyl-CoA through the oxidation of fats, glucose, and some amino acids. (Gita Patel, 2008)

Figure 1: Relationship between carbohydrate, protein and fat metabolism.

Sources from: http://www.elmhurst.edu/~chm/vchembook/600glycolysis.html




PHYSIOLOGICAL BENEFITS:

In nasi kandar, rice is for the ingestion of a large number of carbohydrates among those ingredients and there is around 76.1% carbohydrate are come from the rice. The function of carbohydrates is to provide energy for the body, especially the brain and the nervous system. Sugars and starch act as the perfect fuel that enable us to carry out our physical activities efficiently and effectively for instant energy generation. It is an excellent source of energy for the many different activities going on in our cells. In fact, carbohydrate is one among the three prominent macronutrients that serve as excellent energy providers, the other two are fats and proteins. Carbohydrate foods are low in calories and high in fiber. (Emory University, 2008) Fiber can keep our bowel function going smooth, because it increases the number of bowel movements per day and improves the ease with which a stool is passed. Besides, fiber can help in weight control, diabetes, and prevent heart disease. (Marks, J.W., 2009)

Rich protein foods in nasi kandar are fried chicken and fried squid. Protein can act as antibodies which involve in defending the body from antigens, a contractile protein which involve in muscle contraction and movement, and an enzyme that facilitate biochemical reactions. Moreover, it is for growth and repair of body tissue of the body. (Wikipedia, 2009)

Fried chicken is the main ingredient which provides the fat in nasi kandar and it is around 59.8% of the total fat. Fats are a compound known as lipids. It provides the most important reservoir of stored energy as adipose tissue. In addition, fats also function as the transportation and use of vitamins A, D, E, K, and for other substances which are fat soluble. Those vitamins would not be able to function if without fat in the diet. The other functions of fats include protection for the vital internal organs, prevent loss of body heat, provide the covering for nerves, production of hormones to regulate and initiate body activities. (Dr. Gruber, B., 2002)



MODIFICATIONS OF NASI KANDAR:

If we assume that a female eat 3 meals per day, then the amount of the total energy, carbohydrate, protein and fat should be divided into 3 (33.3%) from the Recommended Nutrient Intakes (Table 2). The Recommended Nutrient Intakes per meal for Female is recorded on Table 3.

Table 2: Recommended Nutrient Intakes for Male and Female


(NAL, 2009)


Table 3: Recommended Nutrient Intakes per meal for Female


(NAL, 2009)


From the table 1, we can know that the total energy, protein and fat are more than the Recommended Nutrient Intakes per meal for Female on Table 3, especially the protein consumption, because it is already more than a requirement of RNI daily for protein by eating one meal only. If we eat one meal then can get the whole day protein, we will get the protein toxicity easily because we are impossible to eat a meal without protein. The reason is because every food must contain protein whether it is contain more or less only. Protein toxicity will result to the kidney disease, diabetes, heart disease and long term untreated high blood pressure. (Wikipedia, 2008)

Therefore, we must modify nasi kandar in order to let the human being get maximum benefits and try to reduce the adverse effects of nasi kandar. Actually we can evaluate that nasi kandar is harmful to human being if we didn’t modify it. Table 1 showed that the total carbohydrate per meal is lower and the others are higher. Hence, we should try to lower the total energy, protein and fat. On the other hand, make the total carbohydrate higher. The rice and okra will be no change at all. We can choose boiled egg to eat rather than choose fried egg. The reason is because the energy, protein and fat are much higher in fried egg than boiled egg. Our purpose to modify nasi kandar is to lower these three things and let carbohydrate intake become higher. Boiled egg is totally suitable for our modification.

Apart of the selection of egg, the most important ingredient is chicken. Which part of the chicken should we choose? We can refer to the nutrient database according to NAL, 2009 and those values are recorded on Table 4. In fact, the chicken breast is the best part for us to choose because it is low in energy, carbohydrate, and fat while high in protein. Unfortunately, it is a bad choice for us to choose if we add into the side dishes of nasi kandar, because we need to make carbohydrate higher and protein lower. The protein inside chicken breast is too high, we will get protein toxicity faster. So, this is testing our experience. According to my experience and knowledge, I think chicken thigh is the best part for us to eat with nasi kandar. I do not choose chicken wing because the energy and fat content are too high. I only can choose between chicken thigh and chicken drumstick. These two parts, the energy, protein and fat are almost the same, not different very much. Therefore, the main point is the carbohydrate. Ladies and gentleman, you all still remember the carbohydrate intake for nasi kandar should be lower or higher? Yes, the answer is higher for carbohydrate. So, ladies and gentleman, which parts should we choose between chicken thigh and chicken drumstick? Yes, of course chicken thigh, because it got a higher carbohydrate.

Table 4: Nutrient database of some parts of Chicken


(NAL, 2009)


Fried squid is a type of seafood, normally seafood is contains a high energy and protein. For the modification of nasi kandar, I am strongly disagreed the consumer choose fried squid as side dishes and I hope consumer can choose cabbage to replace fried squid. The fried foods are consider as unhealthy foods, the chicken is fried already then we do not choose second fried foods is a better decision, we cannot ignore our healthy and eat whatever we like to eat, we must consider the nutritional composition and follow the food guide pyramid. According to the food guide pyramid, there are more servings we should eat at vegetable group than meat group per day. Hence, we should choose another vegetable to eat, and I suggest cabbage replace fried squid because cabbage contains no fat, low in energy and protein.

The last thing we can modify for nasi kandar is the curry. Generally, the cooker will use coconut cream to cook the curry. In compare, coconut milk is better than coconut cream. Although they two got saturated fat, but coconut cream contains much more saturated fat than coconut milk. After modification, all prominent macronutrients and energy are improved. The total energy, protein and fat are decrease; total carbohydrate is increase. Even though the total protein required still high but the important thing is it got improve already. Although we cannot modify it become the best, but it is the maximum benefit and we reduce the adverse effects already. The nutritional composition of modified nasi kandar is recorded in Table 5.

Table 5: Nutritional Composition of Modified Nasi Kandar


(NAL, 2009)

• 29.6% of total energy required daily
• 17.4% of total carbohydrate required daily
• 67.9% of total protein required daily
• 28.8% of total fat required daily



CONCLUSION:

A healthy life is come from the healthy diet every day. We must always make healthy food choices and take care about our healthy lifestyle. In conclusion, nasi kandar became a healthier food after modified it, so I hope everyone can take my advice and choose the side dishes which I suggested and modified.



REFERENCES:





Prepared by:
Chin Kai Shien 1000715766
Samuel Lim Chin Hau 1000716154