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ERRATA
kernels were ground in a Waring blender for two 1-min
periods at full speed, mixed with a spatula, and then
reground for an additional 1A rain. Then, about 9 g of the
material were transferred directly to a 500-ml grinding
container of the Sorvall Omni-Mixer and ground for 1A rain,
mixed with a spatula, and ground for an additional % rain.
The oil contents of ground peanut samples were determined
as in Method Ab3-49 except the extractions were con-
ducted for 4
continuous hours.
Peanut kernels (50 g) were initially ground in a Waring
blender, then 9-g portions were transferred to the Omni-
Mixer to obtain smaller particle size (100% passing through
a 20 mesh and 91% passing through a 60 mesh screen).
Grinding in the blender alone gave comparable results,
however, the extraction had to be stopped after 2 hr and
sample ground with a mortar and pestle as in the AOCS
method. The Henry Nut Slice/" was tried for slicing of
peanuts but was not satisfactory with low moisture roasted
peanuts because oil was expressed within a few seconds due
to heat generation. The Wiley mill and the Raymond
Hammer mill were also unsatisfactory for grinding because
of the high oil content of peanuts.
The oil content of four samples of raw peanuts by the
improved method was 49.7% -+ 0.06 and by the AOCS
Official Method Ab3-49 was
49.6% +-
0.11. The values
obtained on the individual samples by both methods are in
relatively close agreement ranging from 0.02 to 0.27%. The
coefficient of variation for the AOCS method is slightly
higher than with the improved method (0.22% vs. 0.12%),
and the average deviation is -0.13% for the AOCS method.
Table I shows that the improved method is very repro-
ducible for analysis of oil from different peanut products
(standard deviation, +- 0.05).
These analyses on several wpes of peanut products using
the improved new method demonstrate that a minimum of
oil is lost (less than by the AOCS method) and that the
extraction is complete in a simple operation, thereby
eliminating the possibility of error caused by interruptions
in the refluxing process. This improved method is quantita-
tive and uniform and can be employed to determine oil
content of raw or roasted, fresh or rancid peanuts, peanut
butter, and other peanut products.
JAMES C. KUCK
A.J. ST. ANGELO
Southern Regional Research Center
Science and Education Administration
U.S. Department of Agriculture
New Orleans, LA 70179
REFERENCES
1. "Official and Tentative Methods of the American Oil Chemists'
Society," 3rd Edition, Revised to 1976, AOCS, Champaign, IL,
Method Ab3-49.
[Received September 25, 1979]
Errata
In "Quantitative Analysis of Food Fatty Acids by Capillary Gas
Chromatography", JAOCS 56:933, the captions for Figures 4, 5,
6 and 7 are incorrect. They should read:
FIG. 4. Correction
factors for
saturated fatty acids vs chain length.
FIG. 5. Correction factors for fatty acids vs corrected retention
ratios.
FIG. 6. Separation of FAME derived from beef lipid, temperature
programmed
with no
internal standard. Column, see Table I; tern-
perature program: 150.C - 170 C at 0.5 C/rain, then 0.2 C/min
for
16 min, then 1 C/min to 200 C, hold at 200 C until all FAME
eluted. Numbers on peaks refer to identities given in Table II.
FIG. 7. Temperature programmed separation of FAME derived
from lipid
extracted from Zweiback Toast (Nabisco). Column,
see
Table I; temperature program: 150 C- 170 C at 0.5 C/min, then
0.2 C/min for 16 min, then 1 C/min to 200 C, hold at 200 C until
all FAME eluted. Numbers on peaks refer to identities
given in
Table II.
JAOCS March 1980 / 129
