K. T. ACHAYA AND B. N. BANERJEE 275
were considered sufficient warrant for the assump-
tion. The molar percentages for decenoic, dodece-
noic, tetradecenoic and hexadecenoic acids came out
as about 0.1, 0.1, 0.7 and 3.0 respectively, which
agree fairly well with the values 0.3, 0.3, 1.0 and
3.0 of Smith and Dastur [1938] for cow milk-fats of
generally greater unsaturation. The percentages
now indicated must, however, be regarded only in
the nature of an approximation of the true propor-
tions of these acids in buffalo milk-fat though not
far from them.
A further interesting feature of these analyses
is the presence of an acid higher than linoleic, cal-
culated here as a C 20 acid with one double bond
(gadoleic), in the absence of material for more
detailed analysis. The other three analyses (loc.
cit.) in the literature recorded the highest unsaturated
acids as linoleic and the molar percentages as 2.2
and 0.2.
The most striking feature of the present results
is the gradually rising contents of oleic acid as the
amounts of the lower acids decrease, a relation-
ship reflected in a more general way in the R.M.
and iodine values. This is the more marked in
that samples 1 and 2, of about the same iodine
value, could be expected to contain the same amounts
of oleic acid; actually, the proportions are quite
different and the low iodine value of sample 2 is
accounted for by its low linoleic, rather than oleic,
content.
Smith and Dastur [1938] observed very similar
results with the cow in their work on inanition.
They indicated there that several theories of the
origin of these lower acids could account for the
features observed among which was the theory of
Hilditch and his colleagues [1941] that the lower
acids are formed by the breakdown of preformed
oleo-glycerides in the mammary gland. The general
nature of the present results strongly favours this
view, since it postulates a direct relationship between
the two components in question. Moreover, the
presence of lower unsaturated acids probably iden-
tical with those of cow and goat milk-fat is satis-
factorily accounted for in that they represent 'frag-
ments of transformed oleo-glycerides which have
escaped complete saturation to lower saturated
acids'. The recent tentative postulate of Hilditch
and Meara [1944] that the precursor in blood might
well be a linoleo-glyceride does not affect the results
since the production of an oleo-glyceride from a
linoleo-glyceride represents a comparatively simple
hydrogenation.
While the first two ghees analysed are of a pattern,
samples 3 and 4 fall into another class by reason
of their high percentages of stearic acid. That
there appear to be two such fairly distinct types of
buffalo milk-fats is supported by the three other
analyses extant, which are quoted below (Table III)
after conversion in all cases to molar percentages.
TABLE III
Fatty acid composition of ghee (as molar percentages)
—
Butyric . . .
Caproic. . .
Caprylio. . .
Capric . . .
Laurie. . .
Myristic. . .
Palmitic. . .
Stearic. . .
Arachidic . . .
Oleic*. . .
Linoleic. . .
5
10.8
3.3
0.5
1.3
2.4
7.7
19.0
20.9
2.1
29.7
2.3
6
10.9
2.8
1.5
2.4
3.3
10.5
28.7
9.3
0.7
27.7
2.2
7
11.9
2.6
0.7
Trace
3.7
7.9
25.0
14.2
2.6
31.2
0.2
These analyses show that the high percentage of
stearic acid need not necessarily occur where the
content of lower acids is small or that of oleic large
as has happened in samples 3 and 4 of the present
series. In other words the proportions of stearic
acid appear to be fixed by a mechanism independent
of that operating in the fixing of the proportions
of oleic acid on the one hand and the lower acids on
the other.
It is necessary to explain the emphasis- on the high
stearic rather than low myristic contents of the
samples under discussion. Hilditch and co-workers
(loc. cit.) have shown that the tendency in the
butterfats and depot fats of herbivorous mammals
is for the palmitic acid content to remain constant
at about 25 per cent; in addition, Patel, Patel and
Dave [1944] have recently shown that the buffalo
is much more susceptible to feeding vagaries than the
cow and reflects slight changes in its feed by fairly
marked changes in its milk-fat. It seems probable,
therefore, that the low palmitic content while still
tending to constancy is a mathematical consequence
of the high proportion of stearic acid, coupled in
this case with a high oleic content besides.
The mechanism of this high production of stearic
acid is of interest. It can be shown that it cannot
directly be traced to any specific fatty-acid or gly-
ceride structure of an oil, since similar oils have
widely different effects on milk-fat. Since the
precursor of both milk-fat and body fat is the neutral
triglyceride fraction of blood [Maynard et al, 1938;
Aylward, Blackwood and Smith, 1937; Peterson,
Palmer and Eckles, 1929; etc.], it would be safe to
draw comparisons where smilar effects on both are
produced by an ingested fat. Soybean oil does
not produce any untoward effect on cow milk-fat in
*The oleic percentages are about 4 units too high since
lower unsaturated acids were not accounted for.