Z. E. KOTHAVALLA, M. S. PHERVANI AND E. V. SESHACHAYULU                37

The results with brass tinned and un-
tinned cans also show that there is prac-
tically no difference between the two
treatments, i. e. washing soda and
Bentonite and these two are much super-
ior to the indigenous method. The bac-
terial counts of the cans cleaned with
washing soda range from 300 to 2,000,
the average count being 1,094 with brass
tinned cans and 1,161 with untinned cans.
The counts of the cans cleaned with Ben-
tonite vary from 100 to 2,000, the average
count being 1,138, with brass tinned cans
and 1,166 with untinned cans. The cans
cleaned by the indigenous method show
counts ranging from 700 to 14,000, the
average count being 4,666 and 6,083 with
tinned and untinned cans respectively.
The counts of the control cans vary from
6,200 to 380,000, the average count being
130,122, with tinned cans and 1,55,472
with untinned cans. Coliform is absent
in all the trials with washing soda and
Bentonite. In the case of the indigenous
method however coliform is positive in 8
and 11 trials with tinned and untinned
cans respectively. All the controls show
positive test for coliform.

Tbe primary need for clean and sterile
utensils for the safe handling of milk has
already been emphasized. The results of
the present investigation show that Ben-
tonite in its cleansing efficiency stands on
a par with washing soda when used
under conditions described above. The
indigenous method although better than
the controls is inferior to either washing
soda or Bentonite, the reason being that
the mixture of mud and cow-dung cake
ash, used for cleaning, is initially laden
with a high number of bacteria and it is
not possible to destroy a majority of these
organisms, especially the spore formers,
by exposing the utensils only to sunlight.
The results also indicate that for cleaning
milk utensils washing soda may success-
fully be replaced by Bentonite which is
cheaper than the former. The other ad-
vantages of Bentonite observed during the
course of the experiment are that it has
no caustic effect on the hands of the

worker, no abrasive action on metals and
it is not hygroscopic. The utensils clean-
ed with Bentonite also gave as clean and
polished an appearance as those with
washing soda. Again since it is in a
powder form it can very easily be handled.

SUMMARY AND CONCLUSIONS
They are as follows:

(a)  The comparative efficiency of wash-
ing soda, Bentonite and indigenous,
method in sanitising milk utensils
has been studied.

(b)  There is practically no difference in
the bacterial counts of the bottles
and cans cleaned with washing
soda and Bentonite.

(c)  The indigenous method although
much better than the controls is in-
ferior to washing soda and Bento-
nite in its cleansing efficiency (as the
plate counts show).

(d)  Bentonite is as good as washing
soda in its cleansing efficiency and
may, therefore, be successfully used
in place of washing soda, being
cheaper than the latter, for cleaning
milk utensils.

(e)  Bentonite has several other advant-
ages over washing soda such as:—

(i) freedom from caustic effect on the
     hands of the worker,
(ii) no abrasive action on metals,
(iii) non-hygroscopic in nature, and

(f) Bentonite is in a powder form and
can be easily handled.

        ACKNOWLEDGEMENTS

Our thanks are due to Messrs Gilland-
ers Arbuthnot and Co., Lahore (India)
who freely supplied the Bentonite for the
investigation.

               REFERENCES

A. P. S. A Standard Methods for the Examination, of
Dairy Products, 7th Edition, (1939), American Public
Health Association, New York
Barkworth, H. (1941). Dairy Indust., 6., 261
Barker, M. F. (1929). Amer J. Publ. Hlth., 19, 751
Burgwald, F. H. (1939). Bull. Ohio Agric. Exp. Sta,
24, 4
Farral. A. W. (1929). J. Dairy Sei., 12, 95
Kelley, Ernest (1914). Frs'. Bull. U. S. Dep. Agric, 602