Not less than 98 percent of
the material shall he retained on a sieve of silk
or nylon bolting cloth 70 GG (aperture 0.24 mm)
or 250-micron IS Sieve.
NOTE
- Since the sieves made of commercial silk or
nylon bolting cloth may vary in the average mesh
openings from those given in 3.2.1 and 3.2.2,
a tolerance of + / - 7.5 percent is permitted.
3.3 Microscopic Appearance of Starch - When the
finely powdered material is subjected to microscopic
examination, the starch granules shall have a
characteristic appearance as shown in photomicrograph
reproduced in Fig. I., revealing concentric rings
and more small granules than large ones.
3.4 The material shall also comply with the requirements
given in Table 1.
TABLE
1 REQUIREMENTS FOR SUJI OR RAVA (SEMOLINA)
|
Sr.No.
|
Characteristics
|
Requirements
|
Method
of test (Ref to Appendix)
|
|
1
|
Moisture,
percent by weight, Max |
13.5
|
B
|
|
2
|
Total
ash (on dry basis), percent by weight, Max |
1.0
|
C
|
|
3
|
Acid
insoluble ash (on dry basis), percent by weight,
Max |
0.05
|
D
|
|
4
|
Gluten
(on dry basis), percent by weight, Min |
6.0
|
E
|
|
5
|
Alcoholic
acidity (as H2S04) with 90 percent alcohol,
percent by weight, Max |
0.1
|
F
|
4.
PACKING AND MARKING
4.1 Packing - the packages may preferably be of
1 kg, 2 kgs, 10 kgs, 20 kgs, 40 kgs, 65 kgs, 75
kgs or 90 kgs as desired by the purchaser.
4.1.1 For packages above 65 kg, unless otherwise
s agreed to between the purchaser and the vendor,
the material for packing shall be single, sound
A-twill or B-twill jute bags or DW-flour bags
conforming to IS: 1943-1964, IS: 2566-1965 and
IS: 3984-1967 respectively.
Specification
for A-twill jute bags (revised).
Specification for B-twill jute bags (revised).
Specification for DW-flour bags.
4.1.2 The bags used for smaller packs may be polyethylene
bags or polyethylene lined jute bags or any other
suitable material as agreed to between the purchaser
and the vendor.
4.1.3 The mouth of the bag shall be either machine
stitched or hand stitched. If it is hand stitched,
the mouth shall be rolled over and then stitched.
The stitches shall be in two cross-rows with at
least 14 stitches in each row for jute bags of
65 kg and above.
4.2 Marking - Each bag shall be suitably marked
so as to give the following information.
- Name
of the material
- Grade
-
Name and address of the manufacturer
-
Batch or code number
-
Net weight.
4.2.1 All markings shall be applied on the bags
in such a manner that the dye or ink does not
penetrate into the material.
4.2.2 Each bag 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. The ISI
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, which is devised and supervised
by ISI and operated by the producer. ISI marked
products are also continuously checked by ISI
for conformity to that standard as a further safeguard.
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 of drawing representative samples
of the material and the criteria for conformity
shall be as prescribed in the Indian Standard
methods of sampling for processed cereals and
pulses.
NOTE - This standard is under preparation. Until
it is published the method of sampling and the
criteria for conformity shall be as agreed to
between the purchaser and the vendor.
6.
TESTS
6.1 Tests shall be carried out as prescribed under
3.1 and in the appropriate appendices specified
under 3.2 and in column 4 of Table 1.
6.2 Quality of reagents - Unless specified otherwise,
pure chemicals shall be employed in tests, and
distilled water (see IS: 1070 - 1960) shall be
used where the use of water as a reagent is intended.
Note - Pure chemicals shall mean chemicals that
do not contain impurities, which affect the results
of analysis.
Specification for water, distilled quality (revised).
APPENDIX A (Clauses 3.2.1 and 3.2.2)
DETERMINATION
OF PARTICLE SIZE
A-1. SIEVES
A-1.1. Make a nest of 3 sieves of silk or nylon
bolting cloth or IS Sieves, the uppermost having
a designation 20 GG (aperture 1.16 mm) or 1.18-mrn
IS Sieve the middle of 30 GG (apertureO.73mm)
or710.rnicron 18 Sieve and the lowermost 70 GG
(aperture 0,24 mm) or 250-micron IS Sieve with
a cover on top of the uppermost sieve and a receiver
below the lowermost sieve.
A-2. PROCEDURE
A-2.1 Weigh accurately about 1 00 g of the material
into the uppermost sieve and fit it with the cover.
Shake the nest of sieves with the receiver thoroughly
and ensure that all the material on the uppermost
sieve has passed through it. Stop shaking, remove
the nest of sieves and examine the uppermost sieve
to be assured that all the material has passed
through it. Transfer the residues on the lower
sieves separately to two tared weighing dishes
using a brush and weigh each dish.
A-3.
CALCULATION
A-3.1 Material retained on sieve 30 GC or 710-micron
= 100 W1
IS Sieve, percent by weight W
Where W1 = weight in g of the material retained
on sieve 30 GG or 710-micron IS Sieve
W = weight in g of the material taken for the
test.
A-3.2 Material retained on sieve 70 GG or 250-micron
= 100 (W1 + W2)
IS Sieve, percent by weight W
Where
W1 = weight in g of the material retained on sieve
30 GG or 710-micron IS Sieve,
W2 = weight in g of the material retained on sieve
70 GG or 250-micron IS Sieve, and
W = weight in g of the material taken for the
test.
APPENDIX
B Table 1, Item (i)
DETERMINATION OF MOISTURE
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 total ash (C-1.1).
B-2.
CALCULATION
B-2.1 Moisture, percent by weight = 100 (W1 -
W2)
W1 - W2
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 TOTAL ASH
C-1.
PROCEDURE
C.1.1 Ignite the dried material in the dish (see
3-1.1) with the flame of a suitable burner for
about one hour. Complete the ignition by keeping
in a muffle furnace at 550 d to 600 d C until
gray ash results. Cool in a desiccator and weigh.
Repeat the process of igniting, cooling and weighing
at half-hour intervals until the difference in
weight between two successive weighings is less
than one milligram. Note the lowest weight.
Note - Preserve the dish containing this ash for
the determination of acid insoluble ash (D-2.1).
C-2.
CALCULATION
C-2.1 Total ash (on dry basis), percent by weight
=100 (W2 - W)
W1 - W
Where
W2 = weight in g of the dish with the ash
W = weight in g of the empty dish
W1 = weight in g of the dish with dried material
APPENDIX
D Table 1, Item (iii)
DETERMINATION OF ACID INSOLUBLE ASH
D-1.
REAGENT
D-1.1 Dilute Hydrochloric Acid - approximately
5 N, prepared from concentrated hydrochloric acid
(IS: 265-1962)
Specification for hydrochloric acid (revised).
D-2. PROCEDURE
D-2.1 To the ash contained in the dish (see C-1.1)
add 25 ml of dilute hydrochloric acid, cover with
a watch glass and beat 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 the acid
and return it to the dish. Keep it in an electric
air-oven maintained at 135 d + / - 2 d C for about
3 hours. Ignite in a muffle furnace at 550 to
600 d C for one hour. Cool the dish in a desiccator
and weigh. Repeat the process of igniting in the
muffle furnace, cooling and weighing at half-hour
intervals until the difference in weight between
two successive weighings is less than one milligram.
Note the lowest weight.
D 3. CALCULATION
D-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
APPENDIX
E Table 1, Item (iv)
DETERMINATION OF GLUTEN
E-1.
PROCEDURE
E-1.1 Preparation of Material - Grind about 100
g of the material in a pestle and mortar or in
a suitable mechanical pulverizer. Sieve through
fine treble extra silk with an aperture of 0.16
mm (No. 10 XXX) or 150-micron IS Sieve and collect
the material that has passed through. Use this
prepared material for the determination of gluten.
E-1.2 Weigh accurately into a dish about 25 g
of the material. Add about 15 ml of water to the
material and make it into dough, taking care to
see that all the material is taken into the dough.
Keep the dough gently in a beaker filled with
water and let it stand for one hour. Remove the
dough and place it in a -piece of bolting silk
cloth with an aperture of 0.16 mm size (No. 10
XXX) or @150-micron IS Sieve and wash it with
a gentle stream of tap water till water passing
through the silk does not turn blue when a drop
of iodine solution is added to it. Spread the
silk tight on a porcelain plate for facilitating
scraping. Transfer the residue from the silk by
means of a spatula, to a tared porcelain dish.
Spread the wet gluten into a thin layer and cut
into small pieces. Transfer any residue sticking
to the spatula into the porcelain dish. Place
the porcelain dish in an aw-oven maintained at
133 + / - 2 d C. Dry for two hours. Cool in a
desiccator and weigh.
E 2. CALCULATION
E-2.1 Gluten, on dry basis, percent by weight =
10000 (W2 - W1)
W (100 - M)
Where
W2
- weight in g of the dish with dry gluten
W1 - weight in g of the empty dish
W - weight in g of the material taken
M - percentage of the moisture in the sample
APPENDIX
F Table 1, Item (V)
DETERMINATION OF ALCOHOLIC ACIDITY
F-1.
REAGENTS
F-1.1 Neutral Ethyl Alcohol - 90 percent by volume.
F-1.2 Standard Sodium Hydroxide Solution - approximately
0.05 N.
F-1.3 Phenolphthalein Indicator Solution - Dissolve
0.50 g of Phenolphthalein in 100 ml of ethyl alcohol,
95 percent by volume.
F - 2 PROCEDURE
F - 2.1 Weigh 5 g of sample into a conical stopper
flask and add 50 mi of neutral ethyl alcohol.
Stopper, shake and allow to stand for 24 hours
with occasional shaking. Filter the alcoholic
extract through a dry filter paper. Titrate 10
ml of the combined alcoholic extract against the
standard sodium hydroxide solution using Phenolphthalein
as indicator. Calculate the percentage of alcoholic
acidity as sulphuric acid.
F-3.
CALCULATION
F-3.1
Alcoholic acidity (as H2SO4) with 90 percent alcohol,
percent by weight = 24.52 A N
W
Where
A = volume in ml of standard sodium hydroxide
solution used in titration,
N = normality of standard sodium hydroxide solution
W - weight in g of the material taken for the
test.
