Acid Value of Various Domestic Uses Oil

 

Dr. S.Sharma1, Dr. Vikas Kumar Jain2

1Govt. Kamla Devi Rathi Girls College Rajnandgaon, Chhattisgarh

2Department of Chemistry, Pt. Shyamacharan Shukla College, Dharsiwa, Raipur (C.G.)

*Corresponding Author E-mail: ssharmagr8@gmail.com

 

Abstract:

The acid value is the number of mg of potassium hydroxide required to neutralize the free acid in 1 g of the substance. The acid value is  measure of the breakdown of the triacylglycrols into free fatty acids, which has an adverse effect. On account of oxidation of any substance get spoil and decrease the good quality of that substance, oxidation of any substance get increase the acid value. Similarly if oil oxidized its shows high acid value In good oil, the acid value should be very low (< 0.1). The increase in acid value should be taken as an indicator of oxidation of oil which may lead to gum and sludge formation besides corrosion.

 

KEY WORDS: Acid value, Oxidation, oil.

 

INTRODUCTION:

Acid value is taken as an important indicator of oxidation of oil. The acid value is the number of mg of potassium hydroxide required to neutralize the free acid in 1 g of the substance l. Acid base titration techniques in non-aqueous solvents mostly used for determination of acid value in oil.

 

In good oil, the acid value should be very low (< 0.1). Increase in acid value should be taken as an indicator of oxidation of the oil which may lead to gum and sludge formation besides corrosion. Table 1 shows the nature of fat.

 

Table 1

Nature of fat

Expressed as

Molecular weight

Coconut, palm kernel and similar oils

Lauric acid

200

Palm oil

Palmitic acid

256

All other oils

Oleic acid

282

 

MATERIALS AND METHODS:

Different types of oil lubricating oil, Mustard Oil, Soyabean oil, Coconut oil, Peanut oil and Ghee were used for determination of acid Value.  To find the acid value 0.1 N KOH standard solution is used as standard. Phenolphthalein is used as an indicator

 

The acid value for any substance can be calculated using following formula:

 

 

Acid value =     No. of  ml of  0.1 N KOH used x56.1

Weight of the oil taken in gm

 

RESULT:

Table:2, Acid Value and pH of different oil

S.No.

Oil Used

Acid Value

pH

1

Soyabean oil

1.1

3.7

2

Coconut oil

0.37

3.9

3

Peanut oil

2.2

4.1

4

Ghee

0.374

3.6

5

Mustard Oil

1.5

2.1

6

Used fried oil

31

31

7

Sun flower

0.263

4.35

8

Olive oil

1.361

4.6

9

Almond oil

1.8

4.2

 

 

DISCUSSION:

Different types of oil lubricating oil, Mustard Oil, Soyabean oil, Coconut oil, Peanut oil, almond oil and Ghee were used for determination of acid Value. Standard and calculated acid value shown in Table-2, we have seen that the calculated value (observed value) shows deviation from corresponding standard value. The maximum deviation gives the direct consequences of more oxidation of given oil. That means that the given oil is not in a standard form but they have been oxidized. The more the deviation in acid value the less the good quality of oil. This contamination of oil may be due to long time storage of the sample in non-evacuated container with less precaution. The result gives bitter taste and pungent smell. If we use such type of (having more acid value) oil for our daily and domestic use it will cause the illness and take very long time to recover. In case of lubricating oil, the more acid value oil losses it quality to conquer the machine and automobile. Hence such type of study will always be useful and beneficial for life cycle of human beings and machines.

 

CONCLUSION:

After determination of acid value of different oil it get that it come near standard value of respective oil. The more the acid value more the oxidation of that substance, if we know the acid value then the quality status can be determined.

 

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Received on 16.04.2015      Modified on 28.04.2015

Accepted on 10.05.2015      ©A&V Publications All right reserved

Research J. Science and Tech. 7(2): April-June, 2015; Page 109-110

DOI: 10.5958/2349-2988.2015.00012.1