Wednesday, October 28, 2009



INTRODUCTION

Rice (Oryza sativa L.) is one of the important staple foods of almost half of the world population. There is about 90% of its production and consumption in Asia. Cooking is the most important processing steps that is done to provide desirable texture for direct eating. It involves heat and mass transfer. In general, the rice qualities are evaluated based on its color, flavor, texture and eating qualities.
There are some methods to change and improve the rice texture, flavor, color and other properties. It has been reported that the transparency, glossiness and stickiness of rice cooked with acetic acid were increased and hardness was decreased with respect of the acetic acid.



From yesterday to today…
Lemon's health benefits have been appreciated for a long time. It was, for example, often added to various potions as an antidote. Made up mostly of water, lemons are low in calories (32 cal / 100 g) and rich in vitamins C and PP, citric acid and calcium. Their juice is reputed to perk up the weary and those suffering from colds. Lemonade is recommended in the treatment of fever, nausea and hemorrhaging (1 sliced fresh lemon in water or the juice of 1 lemon in half a glass of sweetened water.) In the case of diabetes, lemon decreases blood sugar levels.
Until the early 18th century that lemons received their letters of nobility in the medical world. Tested in England for their numerous properties, it was only in 1932 that their true secret was discovered: their high vitamin C content.

MATERIAL


- Sakura rice


- Measuring cup 1000ml


- Spoon


- Rice cooker


- Rice cooker bowl


- Lime

METHOD


1. 200mg rice was put into a 1000ml measuring cup.


2. The rice was washed for 2 times.

3. The water was drained off.


4. 2 spoon squeezed lime juice was added to the automate rice cooker’s bowl and top up with water up to 400ml.

5. The rice cooker was turned on and the rice is ready in 10 minutes.

RESULT



Hardness: Lower
Adhesiveness: More sticky
Whiteness: Yellowish

DISCUSSION


The hardness of samples that cooked in acidic conditions was significantly lower than control sample hardness. This may be due to that the acidic conditions that promoted by water absorption of amylopectin in rice starch. Also acetic causes it easy to gelatinize and make the rice structure more fluid (Zhou et al, 2007). It also reported that the hardness and adhesiveness are likely to be associated with the hydration process of starch granules. During cooking, the rice granules absorbed moisture and swelled to great extent compared to their original size. The expansion of granule caused ruptures and, hence, amylose leaching. The leaching components can be responsible for decreasing hardness of cooked rice samples (Leelayuthsoontorn and Thipayarat, 2006).
In addition, it was demonstrated that the dissolution and degradation of proteins in the acidic condition might accelerate the absorption of starch. These mutual changes in starch and protein can affect the textural changes such as the increasing stickiness and the decreasing hardness of acidic treatment (Ohishi et al, 2007).
Decrease in gelatinization temperature by acidic samples may be due to the starch granules that became fragile and broke down relatively rapidly after acidification. Acidic rice flour paste showed lower tendency of retro gradation. This may be ascribed to the short-chain starch molecules that appear due to acid hydrolysis, which were very active to form a highly ordered crystalline structure (Wang et al, 2000). Ohishi et al, showed that the rice starch heated with acetic acid was easy to gelatinize compared to that without acetic acid.



Rise and Shine
When it comes to a glowing complexion lime helps kick-starts metabolism and bowel function and also rejuvenate the skin with vitamin C.

In Sickness and In Health
Lime boost the immune system and help fight off infections. It will help ward off colds, stomach disorders and serious infection. Lime have strong antibacterial properties. Therefore, they are good in preventing several bacteria-caused illnesses, including the stomach flu.

Antioxidant
Lime are an excellent source of antioxidants. Antioxidants rid the body of toxins as well as the free radicals that cause aging.

Lime is also so famous as a cure for scurvy, the disease which is caused due to deficiency of vitamin-C and characterized by frequent infections with cough and cold; cracked lips and lip corners; ulcers in tongue and mouth; spongy, swollen and bleeding gums etc.

REFERENCES

1. Ohishi, K., M. Kasai, A. Shimada, K. Hatae, 2007. Effects of acetic acid on the rice gelatinization and pasting properties of rice starch during cooking. Food Research International, 40: 224-231.

2. Wang, H.H., D.W. Sun, Q. Zeng and Y. Lu, 2000. Effect of PH, corn starch and phosphates on the pasting properties of rice flour. Journal of Food Engineering, 46: 133-138.

3. Leelayuthsoontorn, P. and A. Thipayarat, 2006. Textural and morphological changes of Jasmine rice under various elevated cooking conditions. Food Chemistry, 96: 606-613.

4. Zhou, Z., K. Robards, S. Helliwell and C. Blanchard, 2007. Effect of storage temperatureon cooking behaviour of rice. Food Chemistry, 105: 491-497.



Here are some additional references for the lime... ^^

- Lime juice, Best-Home-Remedies. [Online] [Access on 23 October 2009].

- Lemon Juice Health Benefit. Ezine articles, Pederson. [Online] [Access on 24 October 2009].

- Misra N, Batra S, Mishra D. Fungitoxic properties of the essential oil of Citrus limon (L.) Burm. against a few dermatophytes. Mycoses 1988 Jul;31(7):380-2 1988. PMID:13150.

- Miyake Y, Murakami A, Sugiyama Y, et al. Identification of coumarins from lemon fruit (Citrus limon) as inhibitors of in vitro tumor promotion and superoxide and nitric oxide generation. J Agric Food Chem 1999 Aug;47(8):3151-7 1999. PMID:13130.

- Ogata S, Miyake Y, Yamamoto K, et al. Apoptosis induced by the flavonoid from lemon fruit (Citrus limon BURM. f.) and its metabolites in HL-60 cells. Biosci Biotechnol Biochem 2000 May;64(5):1075-8 2000. PMID:13120.