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Thread: How to calculate SNF of milk?

  1. #1

    Join Date
    Apr 2005
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    Default How to calculate SNF of milk?

    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.

  2. #2
    Ashwini's Avatar
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    Apr 2005
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    Default SNF in milk

    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

  3. #3

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    Apr 2005
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    Default How to correct Lactometer reading?

    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..

  4. #4
    Ashwini's Avatar
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    Default Lactometer reading

    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

  5. #5

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    Apr 2005
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    Default

    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..

  6. #6
    Ashwini's Avatar
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    Default SNF in milk

    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

  7. #7

    Join Date
    Aug 2014
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    Default

    I want to know more about the ).72 factor, how does it come, and how does it varyy from place to place. Here in UP, I see this factor as 0.5 and ).14.....so many time there is confusion and unnecessary discussions while selling the milk.
    can you or someone else clarify it.

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