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Thread: How to calculate SNF of milk?

  1. #1 How to calculate SNF of milk? 

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    Hi I want formula to Calculate SNF of milk . I am from Maharashtra INDIA so the formula should be applicable to that place. I mean if it is not universal.
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  2. #2 SNF in milk 
    Ashwini's Avatar
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    Hello,

    Solids not fat(SNF) can be estimated with a formula.
    Herez the formula -----Intially the Total solids(TS) need to be calculated.

    TS = (L-1) * 1000/4 + (1.22* fat%) +0.72
    L= corrected lactometer reading.
    Lactometer is the instrument used to measure the specific density of milk.
    Fat percent can be estimated by Gerber test for fat.
    This test is used to determine the fat content of the milk. 10.94 ml. of milk at 20 degrees Celsius is added to a butyrometer together with sulphuric acid and amyl alcohol. After centrifugation, the sample is put in a 65 degrees Celsius water bath and read after 3 minutes. The fat content from this reading should not be less than 3%.

    SNF = (TS- fat %)

    The formula remains the same all over India.

    Regards
    Ashwini S
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  3. #3 How to correct Lactometer reading? 

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    Thnaks Ms Ashwini
    I understood the formula. One more quaestion when you say corrected Lactometer reading .

    As Lactometer shows specific gravity ,It must be changing with temrature.
    The reading I take is in F( celcfahrenheitius).
    How do we correct reading..

    For example if you have at (80) 0F reading as 1.030 what is the reading at (70 ) 0 F ?

    Can you put some light on this matter..
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  4. #4 Lactometer reading 
    Ashwini's Avatar
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    Hi,
    Lactometer reading does vary with temperature as you say. If its in fahrenheit convert it to degree celcius. I will give you a table with the help of which you can correct the readings.

    Temp (C) ------ Correction

    17 ----------------- ( -0.007)
    18 -----------------( -0.005)
    19 -----------------(-0.003)
    20 ---------------- ( 0.000)
    21 -----------------(+0.003)
    22 ------------------(+0.005)
    23 ----------------- (+0.008)
    24------------------( +0.011)



    Regards,
    Ms. Ashwini S
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  5. #5  

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    Ms Ashwini

    Are you sure about these values . Becoz as per the table we reduce 7 points with just three ( 0C) reduction in temp. which is too high.

    At our place we check specific gravity wit lactometer which reads from 1 to 30 . But as per table you gave it seems really suspicious to reduce 7 points just for 3 0C.

    It may be possible that your table is correct but I am not applying it correctly.

    Did you use these values ? If yes you may face similar problem. Do you have some material to elaborate on this matter plz do it..
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  6. #6 SNF in milk 
    Ashwini's Avatar
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    hi

    Please chk this site if you are unable to calculate. Its got the A to Z of milk testing.

    www.fao.org/ag/againfo/subjects/ documents/LPS/DAIRY/dap/mpo/chap4-2.htm

    I checked in two places and the values are the same. May be you are calculating ina different way.

    Ashwini S
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