Determination of Acid value & Free Fatty Acid(FFA)_A Complete Procedure (AOAC 940.28 & ISO 660.2009)
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- Опубліковано 30 лип 2024
- The acid value (AV) is a common parameter in the specification of fats and oils. It is defined as the weight of KOH in mg needed to neutralize the organic acids present in 1g of fat and it is a measure of the free fatty acids (FFA) present in the fat or oil. This video represents a complete procedure for determination of Acid value and Free Fatty Acid of oil samples.
NOTE: There is a mistake in the formulae of acid value, mentioned in this video, and the formulae for FFA is not given in this video.
Both corrected formulae & calculations of Acid value and FFA are given below:
*Acid value (as oleic acid) = 56.1×V×N
---------------
W
So, Acid Value = 1.6
*Free fatty acids (as oleic acid) = 28.2×V×N
---------------
W
So, FFA = 0.805 percent by weight
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Thanks a lot such types of video uploaded. I see and saw your all video and i feel very happiness. Great wishes for you and your channel.
Thanks.
Thank you for complete step and most easiest method you are using.
I never regret of knowing this great Institute of Learning.
Nevertheless, free fatty Acids determination was not done in this video
Thanks.
Free Fatty Acid calculation is given in the description section. Please take a look
Thanku so much Mam Acid value of oil experiment ke liye🙏🙏🙏🙏🙏
Thank you for your upload videos and I'm very interested to learn that teaching for easily understanding!!!!❤❤❤❤
I'm new for your channel and I will introduce my position to you!!!
I'm one among chemistry student:
1. Under graduate,
2. Bachelor degree,
3. 4th year
Thank you so much and I will follow you always !!!!!
hello ..i have a doubt ....to get FFA in percentage wew have to use the same formula and also FFA does not have any unit....another question can i use formula for the estimation of FFA in Pearl millet flour..?
kindly give me a suggestion...
Tomorrow is my practical and it is helping me alot
From Pakistan
Glad to know
Hi, thanks for the video. Why do we boil the ethanol-sample solution and what percent phenolphthalein solution are you using? Also, can I neutralize ethanol using KOH instead of NaOH? Thanks again!
Thanks for those videos❤️🔥❤️🔥
You are welcome
This is great! Thank you :D
Glad you like it!
MicroChem's Experiments people, I just saw your posts today and you are such smart, human angels for sharing your knowledge in such a simple and easy way to understand. Thank you so much! May God/Karma/Life blesses you and your loved ones today and always! Do you have any videos of how to prepare samples, standards, control, and blanks for ICP-OES? And how to do analysis with a GC and an UV? Thank you, you are appreciated!
Thank you very much for your appreciations. We do not have video for ICP-OES. In future, we will try to make video on it. We will upload video on GC soon. Stay with us.
I am microbiology test only analysis,but your video will help to learn Crude protein analysis,crude fiber and crude fat test is very easy and result is very good
Thank you soo much for such appreciation. We uploaded standard preparation for AAS. We. Also uploaded one video for GC and several video for spectrophotometer analysis. In future we will upload for ICP-MS too. Stay with us. Soryy for late reply.
Very educating and simple too, but please how do I estimate the free fatty acid from the acid value dealing with Shea butter sample
Can we use 0.5%phenopthalein indicator??For av determination.
Only 2-3 drops of phenopthalein indicator is added what if we add 6-7drops.
Thanks so much
Maam
For giv6
In detail knowledge for us
You are most welcome.
hi, how do we know the "expected acid value" if let's say I do not know the profile of the oil I am about to test?
If you dont have any reference expected value then test your sample twice or thrice asuming high, medium & low acid value.
After performing the three tests you will get an idea about the acid value of your sample.
Hi, do you know if I could use Isopropanol instead of Ethanol?
I did acid value today on hydrogenated vegetable oil as per USP method. United States pharmacopeia. They say to melt the sample (was in powder form) and add 100 ml of hot alcohol previously neutralized with NaOH, to phenolphthalein ts. Then add 1 ml of the indicator. How would you interpret this? Do I add the naoh to the alcohol first and then heat or do I add after heating? And the indicator after heating? Pls help. I think I messed up here somewhere so it didn't pass
Do as done in this video
Thanks a lot for your effort.
What is the range of acid value?
How to avoid measuring mineral acids (e.g. sulfuric acid) and organic acids, only I would like analyze Free fatty acid content.??
Good day is there unit for the acid value ? due he did not write it
What is the unit lf the final value gotten. Is it in percentage or mgKOH/g
from your test how can i measure the amount of insoluble matter in alcohol amd water
It is not the test method for insoluble matter in alcohol and water.
Why do we put an equal amount of alcohol and ether when determining or performing for acid value?
We use 50ml of neutralized ethanol to dissolve the oil sample because AOAC method said so
How to calculate the acid number of a mixture of oil? If i want the total mixture of oil is 10 gram and i have 2 oil with diffent acid number. One is 0,1 and the other 4. How much of each of these oils? Thank you
Sorry we are unable to explain for oil mixture.
When the sample is prepared you are boiling it, but my experiment wants to see the effect of frying on acid value so is it possible to do it in a different way to prevent boiling of the sample?
No. Boiling is needed for melting, dissolving and mixing of oil with ethanol. Boiling does not change the acid value significantly
Can I use this method to know bacterial acid value? And my lipid content of bacteria is. 0085gm then the procedure will be the same? Like 50 ml ethanol etc
No idea about your sample. You can try and let me know the results.
Great video still have question when I want to measure the acid value of candelilla wax it starts to solidified in the middle of titration ? How to solve this ? And will it affect 9n acid value?
Keep the flask on hot plate while titration and use magnetic stirrer to agitate the solution.
Hello, is this protocol available for measuring AV of ghee ( butter oil )? and can you mention the link of the AOAC please? Thank you
You can measure the acid value of ghee by this same method.
Excellent video
Thank you so much. Stay with us
How to know whether the ethanol is dissolved or not because my solution always separated as ethanol and oil after i removed it from hot plate
No problem. During heating, acidic properties comes with ethanol.
How to find out free fatty acid value in cake mix?
i wanna ask, we do the titration while the mixture is still hot or not?
Son of snitch, do titration while it is hot.
very informative video...
Rahul Pawara, thank you so much. Be with us.
Thanks so much for sharing, we dissolve sample with solvent may be (hot ethanol) or a mixture of 96%ethanol and diethyether(1:1)...and heating the sample with solvents if necessary by gentl heating about 40°c..
Because high temperature destroy triglyceride and realise free fatty acid ..
We didn't try this method you described. Please try our method described in our video which was made by following the AOAC strictly.
What is the difference between ffa value and acid value? And also mass of oleic acid is 282.5 so why 28.2?
Take help from Google for detailed explanation
NOTE: There is a mistake in the formulae of acid value, mentioned in this video, and the formulae for FFA is not given in this video.
Both corrected formulae & calculations of Acid value and FFA are given below:
*Acid value (as oleic acid) = 56.1×V×N
---------------
W
So, Acid Value (mg/g) = 1.6
*Free fatty acids (as oleic acid)= 28.2×V×N
---------------
W
So, FFA = 0.805 percent by weight
i have noticed in the early video, thank you for correction!
@@AriffMahtar Actually we did a silly mistake in the calculation. Please ingore it.
Isn't 56.1 the molecular weight for KOH.. And you used NaOH in the experiment
@@crayversace2804 AOAC method said to use 56.1 as the factor of this calculation for in both of the cases whether you use 0.1N KOH or 0.1N NaOH solution.
So what would the formula be if I used 0.1 KOH, 10 grams of oil, and had a titration volume of 0.76
Sir i have a question . Is there any machine available to check moisture for ghee?like the BR check machine .
You can use general moisture analyzer
hi is acid value depends upon the number of grams of fat taken. i take normally 1 gm of mustard oil to calculate ffa .what should be its range in that case
You should take 10g sample
my keen request to post a video on lipase estimation by titration method for flour samples .....
Will try
May I know how long did the oil sample+ neutralized alcohol took to boil?
It depends on the temperature you applied. Time doesn't matter, you just need to boil. That's all.
Hi, does the mixture have to be heated until boil? if so, how long should i let it boil?
Boil until the oil is dissolved in ethanol completely
Thanku so much ma'am 🔥✨❤️
Most welcome 😊
Miss thanks for sharing, yours methods are so easy which helps easy understanding. Keep it up.
My pleasure 😊
Thank you so much
You are welcome
Can you give me the "Determination of Oil Analysis" manual if I need it?
No sir. No documents will be provided
Please Ihave a question, why did you heat the ethanol with sample and what is the time required to heat
Boiling is needed for melting, dissolving and mixing of oil with ethanol. Boil for 1 min
Thanks from your good video. I have a question. Can we use acetic acid 33٪ instead of concentrated by adding three times more acetic acid ؟
You do not need acetic acid in this experiment
In our laboratory we are using methanol instead of ethanol, but the results are nearly same, is it possible?
You should use ethanol
Miss why are you adding phenopthline for twice?. Also requested share procedure for rancidity test with reference. Thanks.
Irfan Ali, Thanks for your question. Yes adding Phenolphthalein twice is needed for this test. First time Phenolphthalein is added to carry out the neutralizing titration. Second time, it is added for the Acid Value determination titration. Both are needed because during boiling Phenolphthalein activity is lost in heat. So you have to add Phenolphthalein again before starting the Second & Final titration.
We will try to upload a video for rancidity test very soon. Stay with us.
What was the actual temperature of the Hot Stirrer during heating the sample with the neutralizing Ethanol? Thanks for your prompt feedback.
You need to heat just at the boiling point of the ethanol. May be at 80 degree Celsius.
@@MicroChemsExperiments thank you very much!!!
@@AshishKumar-rf5tv you are welcome Sir
Thanks a lot..but i have a question, this method is also applicable to virgin coconut oil
Yes.
When I needed to get Acid value in our laboratory for fats I used 0.1 N NaOH for titration , but when I calculated I multiple by 56.1 . our specification in our laboratory said that. Is that right?
Right
But why ? Please give me the reason
I think when you titrated with 0.1 NaOH you multiple by 40.001. so I said to my boss that our specification is wrong because we multiple by 56.1
@@user-if7df1rm2w if you follow AOAC method, it is written that you have to use factor 56.1 whether you use KOH or NaOH
Hi. Where can we get the official copy of this method? is it available online?
Not available at online. You can purchase from us. Write us at mail.mic.chem@gmail.com to purchase
great work
Thank you
Thnks ❤
Thanks a lot,
Pls peovide FFA method & It's calculation
This video is also applicable for FFA test. Just FFA calculation is different. FFA calculation is given in the description section of this video.
Can you please provide a documented file or article of the procedure ?
Sorry. We don't provide any document.
How to do solid sample like mixes for free fatty acid procedure tell me
Take 10g of crushed and mixed sample and do the same as done in this video.
Can we use methylene blue instead of phenolphthalein? Then what are the procedures?
No. You can't
What is the maximum value of ffa for a good oil...?
Different oils have different FFA value. Search on google to get idea about the reference ffa value of an oil sample
Hello, I have some questions. What is the difference between normality and molarity? What is the purpose of standardizing the solution? Finally, why do we need to do the first titration of the ethanol?
1. You can find the difference between normality and molary from google.
2. Purpose of stadardization is to know the exact concentration of any solution.
3. Normally ethanol is slightly acidic. So first titration of ethanol is done to make the ethanol neutral as if it does not interfare the acidity of our oil sample.
@@MicroChemsExperiments So for every trial of this procedure, do I need to standardize the solution every time?
Also, may I ask where you got the expected acid values from? I need a citation. Can you please also explain the formula in the calculation section? Thank you very much for your help. I appreciate it :)
@@mysticforest6345 No. But standardize when you will analyze your sample on a different day.
@@mysticforest6345 Search on Google and find the reference value from journals and publications. You can also find it from countrys standard of that sample.
Please I need from you to give me the updated AOAC method If you have
Sorry, we don't provide any document
Thanks for the video. A question though,what about orange peel oil!? What procedure is useful?
This method is applicable for all kinds of oil sample.
@@MicroChemsExperiments thank you. About the standardization, how is it performed please? The steps weren't mentioned here.
Please tell me that the determination of Acid value with FFA is different?
Please read the description section
Is it okay if im using methanol instead of ethanol?
No. That will be wrong
thank you for this clarifying experiment, i have a question, you used 10 g of oil, bcs i don't have enough samples
what if i used only 2 g of oil, do i need to divide all mixtures by 5? Please reply me
g is not enough for the analysis. Do the experiment using 10g.
Thanks for sharing easy way to learn. Why you boiled the sample
For proper mixing of oil
Fats/oils don't dissolve fully in ethanol at room temperature but do dissolve at the boiling point of ethanol. For this test to be accurate, the oil needs to be fully dissolved in the ethanol, so the ethanol is heated to its boiling point to ensure the oil is all dissolved.
Thanks a lot for sharing this very informative video. I have a question, can I replace EtOH 96% or 70% instead of 99%?
You can use 96% but not 70%
Can you explain why you perform this test
I really love your easy methods.
Please help with this question. Based on this method , my expected acid value is 15-75.
Will it be right to use 0.5g of sample and 50 ml of ethanol?
Yes. Do it
@@MicroChemsExperiments
FFA content in oil only or also content in dried sesame seeds?
Kindly told me What is the procedure to Determine Free Acid, Total Phosphorus Pentoxide and Water Soluble Phosphorus Pentoxide Presents in Single Super Phosphate ??? It's Urgent
Noted. We will develop video later
But the oil samples doesn’t mix after boiled
Boiling of oil with ethanol will not facilitate to dissolve the oil completely. So no worries about it. Perform the test according to our video. You will get the accurate result.
Thank you
You are welcome
Whats the procedure for groundnut oil ?
Same procedure will be applicable for groundnut oil sample.
Please what is the implication of Acid value on oil quality?
The higher the acid value and free fatty acid content, the lower the quality of the oil
Hi can you do free acid test for honey sample? thanks
Yes. You can
After dissoLving 4gm in900ml we added 96ml d.w?
No. we added an amount of DW which is needed to make the final volume of 1000ml.
Can use this method for detect FFA in milk or milk product?
Yes. You can
Hi dear i have a question. all oil or dalda cooking oil what is calculation
Same calculation
Dissolve 1gram phenolphthalein indicator powder in 100 ml ethanol? Am I right
Yes right
If my sample is margarine (is solid) do I need to melt it first before proceeding with titration?
It would help to add it to your flask. But ultimately it doesn't matter as long as it's totally dissolved in your ethanol before you do your titration.
Correct
Very good bhai
Thank you
Thank you for this video. I want to ask, if we use KOH as the titrant, definitely the formula will will take molecular weight of KOH?
Some measures of free fatty acids use KOH as the standard while others use NaOH. To convert from KOH to NaOH, multiply by 40/56.11. Likewise, multiply by 56.11/40 for the opposite conversion. This ratio is just the molecular weight of NaOH to KOH.
To be clear, the AOAC method uses KOH. If you're titrating with KOH, just use the KOH MW (56.11) instead of 40, and you'll have the right acid value according to the AOAC method.
Yes, absolutely
Pls share the procedure of Active content of Detergent & liquid
Soon
Please help me out, how do calculate FFA from acid value dealing with shea butter sample
Follow the calculation given in the description section of this video
What you calculated in this video is acid value, is it the same with free acid value
Hi. I am completing a similar titration to measure a change in acid value of canola oil after oxidising it in a microwave, and have encountered some dilemmas. After neutralising the ethanol with my NaOH base, I've been mixing 40ml's of it with 10ml of oil, titrating it with NaOH. I did not heat the solution. For the acidification of the oil, I used 50ml of it and left it in the microwave for between 30 and 150 seconds, but when I titrated these samples, no noticeable change in titre value was detected.
Will the titration actually be able to detect a change in acidity after taking the oil samples from the microwave, or did I just not oxidise the samples long enough? Also is it necessary to heat the ethanol before mixing it with the oil to dissolve it properly? Should I try a greater ratio of ethanol to oil, or will it be too much ethanol to detect any changes in the oil sample?
Thank you for your time. I hate to be something of a burden but I do need a response within a day or so, but clearly I am within no right to expect that. I appreciate any efforts to assist me.
We never tried intentionally oxidation of oil. So we dont have any experience about it. But we think that the difference should be noticable in your experiment.
Please conduct your experiment again following this video strictly.
Increase the oxidation time of your sample. Dont use excess ethanol. Use 50ml nutralized ethanol for 10ml sample and heat the ethanol before mixing with sample.
Dont keep any change of the method described in this video. We hope that you will find difference between two different conditions of oil.
@@MicroChemsExperiments Thank you for your quick reply and explicit instruction. I will be sure to re-evaluate my method and follow the instructions of the video more precisely, with the ratios you've outlined. Thank you very much again for your response and kind words. 👍
@@PsykkMusic you are most welcome dear. Waiting for your experiment results.
@@MicroChemsExperiments Sorry to bother you again, but I just had a few further questions questions that have arisen as a result of some continued investigation, if you are willing to answer them.
Primarily, I noticed that no element of the formula used to calculate acid value actually accounts for the particular oil to ethanol ratio, but from my experiments, increasing the amount of oil in the solution lead to an increase in the amount of NaOH used? Fortunately, for my experiment I've found that a 1:5 ratio has yielded results that work well in the calculations thus far, but someone suggested that I should test this with different ratios to further confirm the acid value, but I noticed the formula won't actually account for the ratio. It also doesn't account for the total volume of the oil/ethanol solution. Is there a way to calculate Acid Value to account for changes ratio's and solution volume? If not, I understand.
Also, for the calculation of the amount of Oleic Acid present in the sample, is the formula the same as for the calculation of the Acid Value, just replacing the Molar Mass of NaOH with the mass of Oleic Acid? If so, would you be able to give a brief explanation why?
Furthermore, If you have the time, I was just wondering why the solution needs to be heated? Is it just to increase the solubility of the oil? Could the ethanol be preheated to 95ºC and then be mixed with the oil? When I heat my 60ml samples for 10 minutes on a hotplate at 150ºC, I still notice some oil not completely dissolved? Should I wait until the bubbling becomes more aggressive?
I greatly appreciate your efforts thus far and hope not to disturb you too much further after these comments. I understand I ask a lot, and am grateful for your efforts. Thank you very much for your time and I look forward to your response.
maybe you forgot to add indicator before titration.
or do we need to wait until the mixture is cooled down to room temp?
Son of a Snitch, you have to carry out titration when the misture is hot.
@@MicroChemsExperiments noted. thank you🙏🏻
Son of a snitch means?
good video btw 👍
Thank you so much. Be with us.
Good video btw 🙂🙂🙂😀
Please check my procedure to help me whether i am right or wrong.
I at first take 99% etanol and add it to 5 gm oil sample. Then heat it for 7-10 minutes and then add 1 ml 1% or 5% phenolphthalein indicators and carried out titration Against KOH.
Then a blank titration is done.
Volume of KOH = KOH required for the test - KOH for blank.
Say KOH for Sample = 0.8
KOH for blank = 0.2
Volume of KOH = 0.6
I then use the following formula
ACV = Molarity of KOH * Volume of KOH * Molecular weight of KOH / sample weight.
In this i Don't need to neutralise the alcohol as i carried out a blank experiment.
Correct
Every oil acid value ranges from 1-4 if we take 10 gm oil or different oil has different ranges ?
Every oil has the same range
Different oils have different ranges and you need to adjust your sample weight accordingly. I work at a bioethanol plant that produces distiller's corn oil, which has a very high free fatty acid content (about 15-25). For this, about 0.5 g is appropriate. There's a chart early in the video that gives the right sample weight for different expected FFA concentration ranges.
can I use 0.1M KOH to replace 0.1M NAOH ?
Yes. You can
Can we use petroleum ether in place of ethanol
No
Kindly share the procedure how to determine the acidity of extracted fat in biscuits with reference. Thanks.
Irfan Ali, Okay we will do this very soon. Be with us.
Same here you have any idea brother
sir, I'm using KOH solution for titration, is it okay for me to use methanol as the solvent instead of ethanol?
No. You have to use ethanol
@@MicroChemsExperiments Thank you Sir
What does blank value and titration value in the calculator mean ?
Your question is not clear
I'm assuming your method assumes you don't titrate your ethanol before you add the oil. If so, then you'll titrate the ethanol without oil and use this titre (mL after titration - mL before titration) as your blank. Then titrate the ethanol with the oil fully dissolved, and this titre will be your titration value.
What unit answer?
Dear, please perform Euric acid in Rapeseed meal oil.
This need GC-FID method. We will make video later
Pls provide calculation of FFA as virgin coconut oil
Please follow the calculation given in the NOTE in pinned comment. Same calculation is applicable for all kinds of oils and fats samples.
Kindly mention the proper reference of this recipe. Or any pdf or paper u have followed.
Reference is already mentioned in the title. No pdf is available to share
What is unit for acid value, and you didn't also show the calculation of free fatty acid
Please find the corrected calculations with unit from pinned comment. Thank you
Thank you so much mam
You are welcome
Something is not right I think formula molarity mentioned 40 but actual sodium hydroxide 28.2 is right
Corrected Calculation is given in the description section of this video