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Introduction

ASLAN Özge Cemre D129077 CHEMISTRY EXTENDED ESSAY “Measuring the fatty acid percentage of the reused sunflower oil after numerous times of potato frying and determining the effects of it on human health.” Özge Cemre Aslan D1129077 Session: May 2010 Supervisor: Serenay Tarhan Güler TED Ankara College Foundation High School 1 ASLAN Özge Cemre D129077 TABLE OF CONTENTS Abstract Introduction…………………………………………………………………………………….1 Research Question……………………………………………………………………2 Background Information………………………………………………………………3 Chemistry of Fatty Acids and Oils Information on Effects of Fatty Acids and Oils Experiment Materials…………………………………………………………………………………6 Preparation of KOH and phenolphthalein…………………………………………… 7 Method……………………………………………………………………………………8 Preparing the sunflower oil……………………………………………………………9 Determining the percentage of free fatty acids in the sunflower oil by acid-base titration…………………………………………………………………………………………10 Data Collection and Processing………..……………………………………………………..10 Calculations to find the free fatty acid percentage………..………………………………..13 Conclusion and Evaluation……………………………………………………………………16 Conclusion of the investigation……………………………………………………………….16 2 ASLAN Özge Cemre D129077 Evaluation of the investigation………………………………………………………..17 Appendix Data Processing Error Propagation Bibliography 3 ASLAN Özge Cemre D129077 Change in Fatty Acid Percentage of Oil After Frying Potatoes Measuring the fatty acid percentage of the reused sunflower oil after numerous times of potato frying. Introduction: In the 21st century that we are living in, most of the people changed their habit of nutrients. Fast foods became popular and take the place of main meals because of the faster life which does not let people eat their meals at home. We became addictive to those foods which do not really feed us. The faster the people started to eat, the faster the restaurants became to work. So fast food restaurants found new ways to get used to this hectic life-style. Many companies started to use trans-fats in their foods because they’re easy to use, inexpensive to produce and last a long time. These kinds of fats give foods a desirable taste and texture. So they can make more money with less spending and also be delicious. Trans-fats (or trans fatty acids) are created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid. ...read more.

Middle

Dissolving a sample makes the mixture colourless because free fatty acids in the oil causes the solution to be acidic which means it’s no longer neutralized so no colour can be seen. After these steps 0.01 M alcoholic potassium hydroxide started to add to this solution. And when 30 seconds stable pink colour is seen, used potassium hydroxide will be equal to the free fatty acid volume. After that, free fatty acids which are found in the experimented sample will be transformed into oleic acid as data by the calculations to be able to use the formula to calculate fatty acid percentage. And for these calculations the following equation is used due to the information below: 13 ASLAN Özge Cemre D129077 DATA COLLECTION AND PROCESSING: %A = (V x 0.0028 x 100) / m A: free fatty acids V: volume of the used alcoholic KOH solution m: mass of the sample 0.0028: mass for the 0.01 M, 1 ml oleic acid Molarity number of moles volume M n V Mass of 1 mole oleic acid ((CH2)7CH=CH(CH2)7COOH): 282.4614 g 0.01 number of moles 0.001L For 0.01 M : 10− 5 moles of oleic acid 1 x 282.4614 g oleic acid 1 mole of oleic acid = 0.0028 g n = 10-5moles Total# of frying Trial # Amount of the fried sunflower oil sample (g)(±0.001) Amount of KOH used for titration (ml) (±0.05) 5 1 5.433 71.50 5 2 5.249 67.00 5 3 5.109 65.50 10 1 5.150 61.00 10 2 5.195 62.00 10 3 5.665 65.50 14 ASLAN Özge Cemre D129077 15 1 5.253 54.50 15 2 5.141 48.50 15 3 5.479 53.00 20 1 5.002 19.00 20 2 5.107 25.00 20 3 5.238 27.50 25 1 5.005 10.00 25 2 5.120 15.50 25 3 5.096 12.50 Ta ble 2: Amount of sunflower oil samples with different total frying numbers and the volume of alcoholic KOH that is used to titrate this sample From this table the raw data show a decrease in the amount of KOH solution which has used for titration. ...read more.

Conclusion

3 = 3.6% ± 0.3 ml/g oleic acid Mean of sample 2 = (3.3% ± 0.1 + 3.3% ± 0.1 + 3.2% ± 0.1) 3 = 3.3% ± 0.3 ml/g oleic acid Mean of sample 3 = (2.9% ± 0.1 + 2.6% ± 0.1 + 2.7%± 0.1) 3 = 2.8% ± 0.3 ml/g oleic acid Mean of sample 4 = (1.1% ± 0.1 + 1.4% ± 0.1 + 1.5% ± 0.1) 3 = 1.3% ± 0.3 ml/g oleic acid Mean of sample 5 = (0.6% ± 0.1 + 0.9% ± 0.1 + 0.7% ± 0.1) 3 = 0.7% ± 0.3 ml/g oleic acid 27 ASLAN Özge Cemre D129077 Appendix 2: Error Propagation: Random Error = l observed value – mean value l x 100 mean value Percentage Error For Sample 1: Trial 1: l 3.7 – 3.6 l x 100 => 2.8% 3.6 Trial 2: l 3.6 – 3.6 l x 100 => 0% 3.6 Trial 3: l 3.6 – 3.6 l x 100 => 0% 3.6 Percentage Error For Sample 2: Trial 1: l 3.3 – 3.3 l x 100 => 0% 3.3 Trial 2: l 3.3 â3.3 l x 100 => 0% 3.3 28 ASLAN Özge Cemre D129077 Trial 3: l 3.2 – 3.3 l x 100 => 3.0% 3.3 Percentage Error For Sample 3: Trial 1: l 2.9 – 2.8 l x 100 => 3.6% 2.8 Trial 2: l 2.6 – 2.8 l x 100 => 7.1% 2.8 Trial 3: l 2.7 – 2.8 l x 100 => 3.6% 2.8 Percentage Error For Sample 4: Trial 1: l 1.1 – 1.3 l x 100 => 15.4% 1.3 Trial 2: l 1.4 – 1.3 l x 100 => 7.7% 1.3 Trial 3: l 1.5 – 1.3 l x 100 => 15.4% 1.3 29 ASLAN Özge Cemre D129077 Percentage Error For Sample 5: Trial 1: l 0.6 – 0.7 l x 100 => 14.3% 0.7 Trial 2: l 0.9 – 0.7 l x 100 => 28.6% 0.7 Trial 3: l 0.7 – 0.7 l x 100 => 0% 0. ...read more.

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