IS: 3838 - 1966
Indian
Standard
SPECIFICATION FOR SELF-RAISING FLOUR
FOREWORD
0.1
The Indian Standards Institution adopted this Indian
Standard on 25 November 1966, after the draft finalized
by the Bakery and the Agricultural and Food Products
Division Council had approved Confectionery Sectional
Committee.
0.2
Self-raising flour is made by mixing MAIDA (wheat
flour) with sodium bicarbonate and soluble acid
ingredients in such proportion that, if they are
permitted to react, they yield sufficient carbon
dioxide, which causes aeration without leaving a
marked excess of any of the ingredients. The production
of self-raising flour involves the mixing of MAIDA
and the aerating agents in required proportions
into an efficient mixer until a uniform distribution
has been achieved. The flour is used in the production
of chemically leavened bakery products.
0.3 While formulating this standard due consideration
has been given to the relevant rules framed by the
Government of India under the Prevention of Food
Adulteration Act, 1954. This standard is subject
to the restrictions imposed under that Act, wherever
applicable.
0.4 This standard contains clauses, which call for
agreement between the purchaser and the supplier
at the time of placing the order. The relevant clauses
are 2.2 and 3.1.
0.5
For the purpose of deciding whether a particular
requirement of this standard is complied with, the
final value, observed or calculated, expressing
the result of a test or analysis, shall be rounded
off in accordance with IS: 2-1960. The number of
significant places retained in the rounded off value
should be the same as that of the specified value
in this standard.
*Rules for rounding off numerical values (revised).
1.
SCOPE
1.1 This standard prescribes the requirements and
the methods of test for self-raising flour.
2.
REQUMEMENTS
2.1
The material shall be made by mixing, in required
proportions, MAIDA (wheat flour) obtained by milling
wheat (free from any sprouted grains and conforming
to LG grade of IS: 1009 -1957), sodium bicarbonate
(conforming to IS: 492 -1954) and any of the acid
ingredients specified in
2.1.1.
It shall be in the form of a flour of whitish to
creamy colour and shall be uniform in composition.
It shall be free from lumps; rodent contamination;
insect or fungus infestation; fermented, musty or
other objectionable odour or taste; and dirt, grit
and other adulterants.
Note - The appearance, taste and odour of the material
shall be determined by organoleptic test.
·
Specification for Maida
· Specification for sodium bicarbonate, refined
(tentative)
2.1.1
Acid Ingredients - The acid ingredients shall be
any one or a combination of the following:
4.2
Each container may also be marked with the ISI Certification
Mark.
Note - The use of the ISI Certification Mark is
governed by the provisions of the Indian Standards
Institution (Certification Marks) Act, and the Rules
and Regulations made thereunder. Presence of this
mark on products covered by an Indian Standard conveys
the assurance that they have been produced to comply
with the requirements of that standard, under a
well-defined system of inspection, testing and quality
control during production. This system, which is
devised and supervised by ISI and operated by the
producer, has the further safeguard that the products
as, actually marketed are continuously checked by
ISI for conformity to the standard. Details of conditions,
under which a license for the use of the ISI Certification
Mark may be granted to manufacturers or processors,
may be obtained from the Indian Standards institution.
5.
SAMPLING
5.1 The method for drawing representative samples
of the material and the criteria for conformity
shall be as prescribed in Appendix J.
6. TESTS
6.1
Tests shall be carried out in accordance with the
appropriate appendices as specified in column 4
in Table 1.
6.2
Quality of Reagents - Unless specified otherwise,
pure chemicals shall be employed in tests and distilled
water shall be used where the use of water as a
reagent is intended.
NOTE - 'Pure Chemicals' shall mean chemicals that
do not contain impurities that affect the results
of analysis.
APPENDIX
A
(Clause
2.2.1)
DETERMINATION OF CALCIUM CARBONATE
A-1.
REAGENTS
A-1.1 Concentrated Hydrochloric Acid - sp gr 1.16
(see IS: 265 -1962).
*Specification for hydrochloric acid (revised)
A-1.2 Bromocresol Green Indicator Solution - 0.04
percent (W / V). Weigh accurately 0.1 g of bromocresol
green and grind it with 14.3 MI of sodium hydroxide
solution (0.01 N) in an agate mortar. Transfer 'the
contents of the mortar quantitatively to a 250 ml
volumetric flask and make up the volume with water.
(This solution has a pH range of 3.8 to 5.4. It
turns yellow in an acid medium and blue in alkaline).
A-1.3 Sodium Acetate Solution - approximately 20
percent (W / V)
A-1.4 Oxalic Acid Solution -- approximately 3 percent
(W / V)
A-1.5 Dilute Ammonium Hydroxide Solution - 2 ml
of ammonium hydroxide (sp gr 0.090) diluted to 50
ml of water.
A-1.6 Dilute Sulphuric Acid - 5 ml of concentrated
sulphuric acid, sp gr 1.84 (see IS: 266-1961), diluted
with 125 ml of water.
Specification for Sulphuric acid (revised).
A-1.7 Standard Potassium Permanganate Solution -
approximately 0.05 N.
A-2.
PROCEDURE
A
- 2.1 Weigh accurately about 10 g of the material
into a porcelain or silica dish. Ignite the material
in the dish with the flame of a Meker burner for
about one hour. Complete the ignition in a muffle
furnace at 600 d +/- 20 d C to gray ash. Cool, add
5 ml of concentrated hydrochloric acid, allowing
the acid to rinse the upper portion of the porcelain
dish, and evaporate the contents of the porcelain
dish to dryness on a steam bath. Dissolve the residue
by adding 2 ml of the concentrated hydrochloric
acid and heat for 5 minutes on the steam bath, covering
the dish with a watch glass. Wash the watch glass
with water, collecting the water in the porcelain
dish. Filter the contents of the dish into a 400
ml beaker. Dilute the filtrate with water to about
150 ml.
A-2.2 Add to the filtrate 8 to 10 drops of bromocresol
green indicator solution and sufficient Sodium Acetate
solution so as to bring the pH to 4.8 to 5.0 when
the colour of the solution would be blue. Cover
the beaker with a watch glass and heat to boiling.
Add the oxalic acid solution slowly at the rate
of one drop every 3 to 5 seconds, to precipitate
calcium, until the pH is brought to 4.4 to 4.6 as
indicated by the appearance of a distinct green
shade in the solution. Boil the solution for one
or two minutes and allow the mixture to settle overnight
or until clear. Filter the supernatant liquid through
a quantitative filter paper. Wash the beaker and
the precipitate with about 50 ml of dilute ammonium
hydroxide solution, using small quantities at a
time, delivered through a wash bottle. Break the
point of the filter and wash the filter' and the
dish with hot dilute sulphuric acid (at 80' to 90'C)
into a 250-mi Erlenmeyer flask. Titrate while hot
with standard potassium permanganate solution until
the contents are just light pink in colour.
A-2.3 Carry out a blank determination, using all
the reagents in the same quantities but without
the material.
A-3.
CALCULATION
A 3.1 Calcium carbonate, percent by weight = 5 (A
-B) N
W
Where
A
= volume in ml of standard Potassium permanganate
solution used in titration (A-2.2),
B = volume in ml of standard potassium permanganate
solution used in the blank determination (A-2.3),
V = normality of standard potassium permanganate,
and
W = weight in g of the material taken for the test
(A-2.1).
APPENDIX
B Table 1, Item (i)
DETERMINATION OF MOISTURE
B-1. PROCEDURE
B-1.1
Weigh accurately about 5 g of the material in a
dish made of porcelain silica or platinum, previously
dried in an electric oven and weighed. Place the
dish in an electric oven maintained at 105 d + /
- 1 d C for five hours. Cool the dish in a desiccator
and weigh with the lid on. Repeat the process of
heating, cooling and weighing at half hour intervals
until the loss in weight between two successive
weighings is less than one milligram. Record the
lowest weight obtained.
Note - Preserve the dish containing this dried material
for the determination of acid insoluble ash (F-2.1)
B-2. CALCULATION
B-2.1 Moisture, percent by weight = 100 (W1 - W2)
W1 - W
Where
W1
= weight in g of the dish with the material before
drying
W2 = weight in g of the dish with the material after
drying,
W = weight in g of the empty dish.
APPENDIX C Table 1, Item (ii)
DETERMINATION OF AVAILABLE CARBON DIOXIDE
C-1. APPARATUS
C-1.1 Schroeder's Alkalimeter
C-2. REAGENT
C-2.1 Sulphuric Acid - sp gr 1.84
C-3. PROCEDURE
C-3.1
Fill bulb A with water and bulb B with sulphuric
acid to a height of 25 mm above the port C through
which carbon dioxide escapes into the acid. Weigh
the alkalimeter. Introduce about one gram of the
sample through the side opening D, into the decomposition
flask E. Weigh the alkalimeter again. Open the stopcock
F and allow about 25 ml of water to flow into the
flask E. Allow the initial vigorous reaction to
subside. Place the apparatus
over a low flame and boil the solution for about
3 minutes. Aspirate carbon dioxide free air through
the solution by applying suction at G, the air first
passing through soda lime. Weigh the alkalimeter
again.
C-4. CALCULATION
C-4.1 Available carbon dioxide, percent by weight
= 100 (W2 - W1)
W2 - W
Where
W2
= weight of alkali meter with sample, before decomposition
W1 = weight of alkali meter with sample, after decomposition
W -- weight of alkalimeter before introducing the
sample.
APPENDIX
D Table 1, Item (iii)
DETERMINATION OF GLUTEN
D-1.
PROCEDURE
D-1.1
Weigh accurately about 25 g of the material into
a dish! Add about 15 ml of water to the material
and knead it into dough, taking care that, as far
as possible, all the material is taken into the
dough. Keep the dough in a beaker, cover it with
water and let stand for one hour. Remove the dough
and knead it gently under a stream of tap water,
holding it over a piece of silk or nylon bolting
cloth No. 10 XXX, taking care, especially in the
early stages, to retain all the gluten while the
starch and bran wash away. Add to the main gluten
mass any pieces of gluten that might have been washed
away and retained with the bran on the bolting cloth.
Spread the wet gluten, as far as possible, into
a thin layer. Transfer any residue sticking to the
spatula to the porcelain dish. Place the porcelain
dish in an air-oven maintained at 100 d ±
2 d C. Dry for six hours. Cool in a desiccator and
weigh. Heat again the porcelain dish for another
hour in an air-oven maintained at 100 d ±
2 d C. Cool in a desiccator and weigh. Repeat this
process of heating for one hour, cooling and weighing
till the difference between two successive weighings
is less than 2 mg. Note the lowest weight.
D-2. CALCULATION
D-2.1 Gluten (on dry basis) percent by weight = 10000
(W2 - W1)
W (100 - M)
Where
W2 = weight in g of porcelain dish with dry gluten
W1 = weight in g of empty porcelain dish
W = weight in g of the material taken for the test
M = moisture percent by weight (B-2.1).
APPENDIX
E Table 1, Item (iv)
DETERMINATION OF ORIGINAL ASH
E-1.
PROCEDURE
E-1.1
Weigh accurately about 20 g of the material and
transfer to a metal centrifuge tube, about 5 cm
in diameter and 15 cm deep. Add about 250 ml of
carbon tetrachloride and centrifuge the mixture
for 5 to 7 minutes at 1600 rev/min. Allow the centrifuge
to come to rest slowly. Carefully skim off the compact
layer of flour on the surface of carbon tetrachloride
with a large tablespoon, recovering as much flour
as possible in one spoonful. Allow wet flour to
dry overnight.
E-1.2 Transfer the flour completely in a dish made
of porcelain silica or platinum, previously dried
in an electric oven and weighed. Place the dish
in an electric muffle furnace maintained at 425
d C; then gradually increase the temperature to
550 d C. Incinerate the contents until light gray
ash results. Cool in a desiccator and weigh. Repeat
the process of igniting, cooling and weighing at
half hour interval, till the difference in weight
between two successive weighings is less than one
milligram. Note the lowest weight.
E-2.
CALCULATION
E-2.1 Ash original (on dry basis) percent by weight
= 10000 (W2 - W1)
W (100 - M)
Where
W2 = weight in g of the dish with ash
W1 = weight in g of the empty dish
W = weight in g of the material taken
M = moisture, percent by weight.
APPENDIX
F Table 1, Item (v)
DETERMINATION OF ACID INSOLUBLE ASH
F-1.
REAGENT
F-1.1 Dilute Hydrochloric Acid - approximately 5
N, prepared from concentrated hydrochloric acid
(see IS: 265-1962).
Specification for hydrochloric acid (revised)
F-2. PROCEDURE
F-2.1 Obtain the total ash by igniting the dried
material after title determination of moisture (see
B-1.1) with the flame of a suitable burner and complete
the ignition by keeping in a muffle furnace at 600
d C + / - 20 d C until gray ash results. Add 25
ml of dilute hydrochloric acid, cover with a watch
glass and heat on a water bath for 10 minutes. Allow
to cool and filter the contents of the dish through
a Whatman filter paper No. 42 or its equivalent.
Wash the filter paper with water until the washings
are free from acid and transfer the filter paper
to the dish. Keep the dish in an air-oven maintained
at 105 d ± 2 d C for about 3 hours. Ignite
in a muffle furnace at 600 d ± 20 d C for
one hour. Cool the dish in a desiccator and weigh.
Heat again at 600 d + / - 20 d C in the muffle furnace
for 30 minutes. Cool the dish in the desiccator
and weigh. Repeat the process of heating for 30
minutes, cooling and weighing till the difference
in weight between two successive weighings is less
than one milligram. Note the lowest weight.
F-3. CALCULATION
F-3.1 Acid insoluble ash (on dry basis) percent
by weight = 100 (W2 - W)
W1 - W
Where
W2 = weight in g of the dish with the acid insoluble
ash
W = weight in g of the empty dish
W1 = weight in g of the dish with the dried material
(see W2 under B-2.1).
APPENDIX
G Table 1, Item (vi)
DETERMINATION OF CRUDE FIBRE
G-1.
REAGENTS
G-1.1 Dilute Sulphuric Acid - 1.25 percent (W /
V), accurately prepared.
G-1.2 Sodium Hydroxide Solution -1.25 percent (W
/ V), accurately prepared.
G-1.3 Ethyl Alcohol - 95 percent by volume.
G-1.4 Petroleum Ether - distilling below 60 d C.
G-2.
PROCEDURE
G2.1 Dry to constant weight about 5 g of the material
on an electric oven at 105 d ± I d C. Weigh
accurately about 2.5 g of the dried material on
a thimble, extract it with petroleum ether free
from fat on a Soxhlet apparatus and transfer it
to a one liter flask. Take 900 ml of dilute sulphuric
acid in a beaker and bring to boil. Transfer the
whole of the boiling acid to the flask and immediately
connect the flask with a water-cooled reflux condenser
and heat, so that the contents of the flask begin
to boil within one minute. Rotate the flask frequently,
taking care to keep the material from remaining
on the sides of the flask and out of contact with
the acid. Continue boiling for exactly 30 minutes.
Remove the flask, filter through fine linen (about
18 threads to a centimeter) held in a funnel and
wash with boiling water until the washings are no
longer acid to litmus. Bring to boil 200 ml of sodium
hydroxide solution under a reflux condenser. Wash
the residue on the linen into the flask with the
boiling sodium hydroxide solution. Immediately connect
the flask with the reflux condenser and boil for
exactly 30 minutes. Remove the flask and immediately
filter through the filtering cloth. Thoroughly wash
the residue with boiling water and transfer to a
Gooch crucible prepared with a thin, but compact,
layer of ignited asbestos. Wash the residue thoroughly,
first with hot water and then with about 15 ml of
ethyl alcohol. Dry the Gooch crucible and its contents
at 105 d + / - 2 d C in an air oven to constant
weight. Cool and weigh. Incinerate the contents
of the Gooch crucible in an electric muffle furnace
at 600 d + / - 20 d C until all the carbonaceous
matter is burnt. Cool the Gooch crucible containing
the ash in a desiccator and weigh.
G-3.
CALCULATION
G-3.1 Crude fibre (on dry basis) percent by weight
= 100 (W1 - W2)
W
Where
W1 = weight in g of the Gooch crucible and contents
before ashing
W2 = weight in g of the Gooch crucible and contents
after ashing
W= weight in g of the dried material taken for the
test.
APPENDIX
H Table 1, Item (vii)
DETERMINATION OF GRANULARITY
H1-1.
PROCEDURE
H-1.1 Transfer about 10 g of the material to a hand
sieve of silk about 36 meshes per linear and sieve
for two minutes. Brush the upper surface of the
sieve and sieve again for one minute.
H-1.2 The material shall be deemed to have satisfied
the requirement .of the test if not more than one
percent of residue, by weight, is left on the sieve.
APPENDIX
J (Clause 5. 1)
SAMPLING OF SELF RAISING FLOUR
J-1.
GENERAL REQUMEMENTS OF SAMPLING
J-1.1 In drawing, preparing, storing land-handling
samples, the following precautions and directions
shall be observed:
J-2.
SCALE OF SAMPLING
J-2.1 Lot - All the containers in a consignment
belonging to the same batch of manufacture shall
constitute a lot.
J-2.1.1 Samples shall be tested for each lot for
ascertaining the conformity of the material to the
requirements of this specification.
J-2.2 The number (n) of containers to be selected
from the lot shall depend on the size of the lot
(N) and shall be as given in Table 2.
TABLE
2 NUMBER OF CONTAINERS TO RE SELECTED FOR SAMPLING
(Clauses J-2.2 and J-2.3)
| Lot
Sizes |
No.
Of containers to be selected |
|
N
|
,n
|
|
3
to 15
|
3
|
|
16
to 40
|
4
|
|
41
to 65
|
5
|
|
66
to 110
|
7
|
|
Over
110
|
10
|
J-2.3
These containers shall be selected at random from
the lot. To ensure the randomness of selection,
a random number table as agreed to between the purchaser
and the supplier shall be used. In case such a table
is not available, the following procedure shall
be adopted:
Starting from any container, count them as 1, 2,
3 .............. upto r and so on, in one order,
where r is equal to the integral part of N / n,
being the total number of containers in the lot
and n the number of containers to be selected (see
Table 2). Every rth container thus counted shall
be separated until the requisite number of containers
is obtained from the lot to give the samples for
test.
J-3.
TEST SAMPLES AND REFEREE SAMPLES
J-3.1 Preparation of Individual Samples - In the
case of small containers, empty out the contents
of each selected container on a sheet of paper and
mix thoroughly. Cone and quarter as often as necessary
till a quantity of the material not less than 300
g is left. In the case of large containers, draw
with an appropriate sampling instrument small, but
equal, quantities of the material from top, middle
and bottom portions of each selected container so
as to get a total quantity of the material not less
than 300 g. From this, take about 150 g of the material
and divide it into three equal parts. Each part
so obtained shall constitute an individual sample
representing the container and shall be transferred
immediately to thoroughly clean and dry containers,
scaled air tight and labeled with the particulars
given under J-1.1 (e). The individual samples so
obtained shall be divided into three sets in such
a way that each set has a sample representing each
selected container. One of these sets shall be marked
for the purchaser, another for the supplier and
the third for the referee.
J-3.2
Preparation of Composite Sample - From the material
from each selected container remaining after the
individual sample has been taken, equal quantities
of the material shall be taken and mixed together
so .as to form a composite sample weighing not less
than 600 g. This composite sample shall be divided
into three equal parts and transferred to clean
and dry containers made of glass and labeled with
the particulars given in One of these composite
samples shall be for the purchaser, another for
the supplier and the third for the referee.
J-3.3
Referee Samples - Referee samples shall consist
of a set of individual samples (J-3.1) and a composite
sample (J-3.2) marked for this purpose and shall
bear the seals of the purchaser and the supplier.
These shall be kept at a place agreed to between
the two.
J - 4 NUMBER OF TESTS
J-4.1
Tests for requirements given in 2.1 and available
carbon dioxide shall be conducted on each of the
samples constituting a set of individual test samples
(J-3.1)
J-4.2 Tests for, the remaining characteristics,
namely, calcium carbonate, moisture, gluten, ash,
acid-insoluble ash, crude fibre and granularity
shall be conducted on the composite sample as prepared
under J-3.2.
J-5.
CRITERIA FOR CONFORMITY
J-5.1 The lot shall be considered to have satisfied
the requirements given in 2.1 and the requirement
for available carbon dioxide if each of the individual
test samples tested as in J-4.1 satisfies the relevant
requirements.
J-5.2 The lot shall be considered to have satisfied
the requirements for the remaining characteristics
if all the test results as obtained on the composite
sample (see J-4.2) satisfy the requirements for
these characteristics. J-5.3 The lot shall be considered
to have satisfied all the requirements of this specification
if it has been found satisfactory in J-5.1 and J-5.2.