INTRODUCTIONVitamin C or L-ascorbic acid, or

simply ascorbate (the anion of ascorbic acid), is an essential nutrient for humans and certain other animal species. Vitamin C is a water-soluble compound that is essential for life. It is

involved in many processes in the human body, including, the production of collagen in the connective tissue, the synthesis

of dopamine, noradrenaline and adrenaline in the nervous system, and the synthesis of carnitine, which is important in the transfer of energy to the cell mitochondria. Ascorbic acid is an excellent reducing agent and it is easily oxidized. When

juices are titrated with iodine, it is assumed that the only reducing agent being oxidized is ascorbic acid.

ABSTRACTVitamin C or L-ascorbic acid, or simply

ascorbate, is an essential nutrient for humans and certain other animal species. This

experiment is to measure the volume of vitamin C in food product after used different type of method. Method that used for papaya fruit are method 1 as a juice, method two dry papaya and method last cooked on hot plate. As a conclusion, the volume of vitamin C is decrease after we used it in increasing of

temperature.

PROCEDURE

Extract Preparation

Raw Dry cook(microwave)

Cooked(boiling)

Titration of papaya extract with iodine until the all the vitamin C

content react with iodine.

Straining(used 30 ml from straining product)

30 ml strained extract is added with•2 drop HCL•5 ml strach

Raw Dry cook (microwave) Cook (boiling)

•Papaya chopped into small pieces.

•100 g papaya and 100 ml is blended until the material is thoroughly ground.

•The ground extract is strained

•30 ml of strained extract is added with1. 2 drop HCL2. 5 ml starch

•Titration of extract and iodine until the solution stays blue black for 15 min

•Innitial and final reading for titration is recorded.

•Papaya material is dry in microwave about 1 hour.

•100 g dry papaya 100 ml is blended until the material is thoroughly ground.

•The ground extract is strained

•30 ml of strained extract is added with1. 2 drop HCL2. 5 ml starch

•Titration of extract and iodine until the solution stays blue black for 15 min

•Innitial and final reading for titration is recorded.

•100 g fresh papaya 100 ml is blended until the material is thoroughly ground.

•The extract is cooked at the hot plate about 20-30 min.

•The cook extract is strained.

•30 ml of strained extract is added with1. 2 drop HCL2. 5 ml starch

•Titration of extract and iodine until the solution stays blue black for 15 min

•Innitial and final reading for titration is recorded.

Type of extraction(papaya)

Volume ofIodine used

(ml)

Average(ml)

Vitamin C contents(30 g)

Vitamin C contents (100 g)

1 st 2nd

Raw 76 78 77 1.07 3.57

Dry cook (microwave)

42 40 41 0.57 1.9

Cooked (boil) 40 38 39 0.54 1.8

RESULT

Standard 1 mg/ ml ascorbic acid = 72 ml iodine needed.

METHOD 1DISCUSSION FOR RAW PAPAYA

From our result, the vitamin C for the raw preparation papaya is 3.57mg/ml in 100 g for extract. Vitamin C content from the theory in the fresh papaya is 57-68% from 100 g. In addition, the vitamin C needed to consume from our daily meal is 51. 2 mg/100 g. The papaya have 16% vitamin C content compared to orange.

Vitamin C is heat sensitive compound compared to other nutrient in the papaya. This may lead to difficulties to retain it whenever the exposed to heat. The higher the temperature, the increase the rate of nutrient loss.

METHOD 2MICROVE + BLEND

DISCUSSIONFrom our result we have obtain only 0.57 mg/ml in

100g for extract. It shows the decrease of vitamin C level in the papaya that have extract using the microwave first.

microwaving food is not the healthiest way to prepare food, nor is it forgiving to our taste buds- microwaved food just doesn't taste as good!

A microwave oven cooks food very differently than a regular oven. Instead of using external heat to cook the food, microwaves use electromagnetic radiation. Waves of magnetic and electrical energy are absorbed by the water molecules in the food, which causes the water molecules to vibrate intensely. This intense water molecule vibration causes molecular friction, which is what heats the food.

One study found that microwaved broccoli can lose 97% of its antioxidant content, and another found that microwaving asparagus significantly decreased its Vitamin C levels. 

METHOD 3BLEND + COOK

DISCUSSIONLast method that we used to test vitamin C in papaya is we blend

the papaya first and after that we cooked it on the hot plate. We want to know that is it vitamin C value is change after we used different method of cooking it. As the result, we know that the value of vitamin C is change after cooking method is applied compared to standard value of vitamin C. This is because vitamin is easily destroyed by cooking or canning foods and by exposure to air and light. Increase in temperature generally reduces the concentration of vitamin C. The lower the temperature the better the concentration of Vitamin C in fruit juice. Higher temperature does not favour Vitamin C. Papayas (100 g) can provide 57- 68% of the DRI for vitamin C. Papayas had 2-3 times more β-cryptoxanthin than β-carotene.

The content of vitamin C in papaya depend on (Lee & Kader).

Ripeness of fruitType of cultivarSoilWheather

Other than that, the temperature be the common factor effecting vitamin C contents (Muhammad 1998).

The higher temperature, the loss of vitamin C is higher. The best quality of juice drink especially in papaya can be

determined by The minimum moisture content (increase in air

temperature and air velocity caused the reduction of moisture).

maximum enzyme concentration Compared the vitamin C of skin and pulp of papaya from the

Sacho, 2011.Pulp 58.6 mg/100gSkin 7.4 mg/100ml 

MAGIC WRITING

1. Art brush is dipped into the lemon juice

2. Massage is write on the paper

3. Dry paper is submersed into iodine solution

The reaction between starch from paper with the iodine solution

produceCombination blue-purple in colour.

The reaction between vitamin C from the lemon with iodine solution

produceColourless colour.

The colour of paper turn to purple-blue except the writing area.

The colourless colour of writing remain unchanged.

APPENDIX APPENDIX

Extract Preparation

Titration Process.

Colour of titration productTitration Process

Chemshort for kids. (1992) Obtained May 13, 2013 from http://chicagoacs.net/ChmShort/CS92.html

http://www.benhirshberg.com/1/post/2012/07/overcooking-and-microwaving-food-not-optimal.html