FLORIDA AGRICULTURAL EXPERIMENT STATION jI..N .( 4 p
Dairy Science Memo $5-1
October 2, 1953
Preliminary Report: Fractionation of
Butterfat Yields New Data and Offers Approach to
Detection of Butterfat Adulteration at Low Levels
W. A. Krienke and Jack Barrs1
Several requests for the method developed in studies on a new approach to the
problem of detecting substitute (foreign) fats in butterfat has prompted release of
the method and some of the data.
It is considered that perhaps other research workers may desire to obtain data
on other samples of butterfat so that averages may be established for butterfat and
its fractions obtained by selective solidification at specific temperatures, and
that a final statistical evaluation will be possible. It is suggested that a sample
represent the butterfat produced by as large a number of cows as possible. Of
greater importance, however, is "knowledge of the sample from the cows to the
The following table contains data obtained on 9 samples of butterfat produced
in the month of January, 1953, by herds of dairy cows at several agricultural
Source of Original 800F. Liquid
Butterfat Sample Butterfat Portion Reichert-Meissl
No. Fractionated Fractionated Numbers
Agr. Exp. Sta. at 800F. at 700F.
Solid Liquid Solid Liquid Whole Solid Solid Liquid
S P P ,W B.F. 800F. 700F. 700F.
Florida 1 54.7 42.3 49.6 44.0 30.9 30.1 32.2 33.4
Illinois 3 69.2 26.8 61.6 28.0 29.8 29.4 32.2 34.0
Minnesota 4 57.5 39.5 53.3 39.6 30.1 29.6 31.9 33.4
North Carolina 5 65.5 30.8 48.4 42.9 31.2 30.7 32.2 33.4
Nebraska 6 57.0 39.3 49.9 44.0 30.1 29.4 31.3 33.1
Oregon 7 66.0 30.2 44.7 48.0 30.3 29.7 31.1 33.8
Oklahoma-** 8 53.6 43.4 52.1 42.9 28.4 27.7 29.0 31.6
Pennsylvania-**H 9 61.3 33.1 36.5 57.9 28.3 27.5 28.9 30.8
Texas 10 64.1 31.6 1 57.6 34.2 30.4 30.2 31.8 33.5
(Sample No. 2 was lost in shipment and it was too late to obtain another for January,
*Also grams, because original sample of butterfat weighed 100 grams. These do not
total 100 because some butterfat was lost in filter paper and on glassware.
*-Example--The 26.8 grams of liquid fat at 800F. of the Illinois sample yielded 16.5
grams solid fat and 7.5 grams liquid fat when fractionated at 700F. These values
in the table were calculated as percentages of the liquid fraction at 800F.
-*iThe only samples that yielded solid fractions in 4 hours at 900F. They were 20.5%
solid and 77.0% liquid for the Oklahoma sample and.22.0% solid and 75.0% liquid
for the Pennsylvania sample. The data in the table are from other portions
fractionated initially at 800F. and therefore are comparable to the other data.
,Nost of the data were taken from a thesis submitted in partial fulfillment of the
Degree Master of Science in Agriculture, University of Florida, August, 1953.
Graphic illustration of Reichert-MeissI Numbers plotted from data listed in the table.
Solid at Solid at
Obtain the liquid butterfat. Adjust the temperature of a 100 gram portion to
800F. and maintain at 800F. for 4 hours. Filter at 800F. Adjust the temperature
of the liquid fraction to 700F. and maintain at 700F. for 4 hours. Filter at 700F.
(Constant temperature ovens or incubators should be used and the samples should be
placed into 150 ml. beakers in water baths inside the ovens or incubators for best
temperature control during solidification.) (Rapid filtration is desirable.) The
net weight of each fraction is obtained. Reichert-Meissl determinations are made
on the whole butterfat and on the fractions.