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© Kamla-Raj 2010 J Hum Ecol, 30(3): 197-199 (2010)
Efficacy of Stainless Steel as Cooking Utensil Material
for Solar Cooking
Vandana Kaushik and Ranju Bala
Department of Family Resource Management, College of Home Science, Maharana Pratap
University of Agriculture & Technology, Udaipur 313 001, Rajasthan, India
KEYWORDS Rice. Aluminum. Consumers. Shopkeepers
ABSTRACT The study was undertaken with an objective to test the suitability of stainless steel utensil. Market
survey of shopkeepers and consumers indicated a very high acceptance of stainless steel over aluminum. Experimental
research design was used to test the efficacy of stainless steel. The data for testing the efficacy of stainless steel was
collected after pre-testing and standardizing certain parameters viz. rice water proportion for cooking, thermal
performance test under stagnant temperature condition and procedure to be followed for experimental work.
Experiments on cooking time tested efficacy of stainless steel and compared stainless steel with traditionally used
aluminum container in solar cooking. Further the efficacy of stainless steel containers was enhanced by comparing
them with traditional black finish – black board paint. The results of the study indicate that solar cooking can be done
in stainless steel container with some extra time. Stainless steel took merely 4-17 minutes extra in comparison to
aluminum.
INTRODUCTION
Alternative energy sources are far less pollut-
ing than traditional fuel (Sperber 2002). Among
various alternative energy devices, cooker is
gaining high appreciation, solar box cooker may
save millions of women many hours. Food cooked
in solar cooker is more nutritious. Usually alumi-
num black painted pot is used in solar cooker
because of good heat conductivity, lightweight
and low price. It is losing popularity due to its
disadvantages like being highly reactive material.
The rate of reaction specially increases if the food
is acidic. Relationship between alumi-num and
prevalence of Alzheimer disease has been esta-
blished through researches (Jorm 1996). A market
survey of sellers and consumers con-ducted by
researcher has indicated that the preference for
aluminum utensils has reduced by ninety percent
and the material has been substituted by stainless
steel. The steel utensils have been found more
user friendly, corrosion resistant, easy to clean,
and non-reactive. Steel can be more efficient in
solar cooking with finishes. Efforts were made to
test the efficacy of stainless steel in solar cooking,
in order to search a possible alternative to
aluminum cooking utensil. The present study was
taken up with the objec-tives to test the suitability
of stainless steel uten-sils for solar cooking. So
that aluminum container can be willfully substi-
tuted by stainless steel container in solar cooking.
MATERIAL AND METHODS
The study on testing the efficacy of stainless
steel was conducted using solar cooker, unobs-
tructed open space for solar radiation, temperature
recorder and other desired equipment for conduc-
ting experiments. Rice was the standard food grain
used for testing the efficacy of stainless steel for
solar cooking. Rice was selected for three rea-
sons. Firstly, it is a staple food for two-third popu-
lation world over (Ismail 2001), secondly, it is non-
perishable and thirdly, it can be cooked simply
without adding any additives. Experi-mental
research design was used to test the efficacy of
stainless steel for solar cooking. The data for test-
ing the efficacy of stainless steel in solar cooker
was collected in two phases.
Phase I-Pre testing and Standardization:
Efficacy of stainless steel for solar cooking was
test-zed by cooking 100 g rice with 300 ml of water
each time for all experimental purposes. Before
starting the experimentation the following were
determined.
· Rice-water proportion for cooking
· Thermal performance test under stagnant
temperature condition
Corresponding author:
Dr. Vandana Kaushik,
Associate Professor
60, Vidya Nagar, H. M. Sector-4,
Udaipur 313 002, Rajasthan, India
E-mail: vandana kaushik1@yahoo.co.in
198 VANDANA KAUSHIK AND RANJU BALA
· Procedure to be followed for experimental work
Phase II-Testing the Efficacy of Stainless
Steel as Cooking Utensil Material
RESULTS AND DISCUSSION
To test the efficacy of stainless steel as cook-
ing utensil material for solar cooking, a number of
experiments were conducted. Before conducting
actual experiments certain parameters were stan-
dardized.
1. Pretesting and Standardization
1.1 Standardization of Rice Water Ratio:
After conducting various experiments the
researcher reached to the conclusion that to cook
100g of rice, 300 ml of water is required. To reach
this conclusion rice cooked in various ratios were
given to a panel of selected judges for evaluation.
The ratio of 100g of rice and 300 ml of water was
rated as best with 4.21 scores on a 5 point scale.
1.2 Thermal Performance of Solar Cooker:
Based on the experiments conducted for testing
the thermal performance of solar cooker, the ratio
of optical efficacy to heat loss coefficient of solar
cooker was calculated to be 0.153.Since the ratio
was greater than 0.12 (Negi and Purohit 2004) the
selected cooker could be rated as thermally effi-
cient and was selected for conducting experi-
ments for testing the efficacy of stainless steel
for solar cooking.
1.3 Market Survey: To know the consumer
preference for the type of utensil material, 30
shopkeepers and 30 consumers were interviewed
while 80 percent shopkeeper said that steel is more
popular than any other material, 90 percent
consumer said they preferred stainless steel over
aluminum as cooking utensils material.
2. Experimentation for Testing the Efficacy of
Stainless Steel
The actual experiments were conducted after
the above standardizations. The experiments
were conducted to test the efficacy of stainless
steel in solar cooker once by comparing it with
aluminum. The three replicates were taken for all
the variations, thus the observations reported,
are the averages of time, radiation and accepta-
bility scores etc. For all the experiments the
comparisons were made by
Ø Solar cooking in high and low temperature.
Ø Solar cooking with different loads (1, 2, 3 and
4 containers).
The product cooked for each experiment was
given to selected panel of judges for rating the
acceptability. The results of the various
experiments are being reported.
Comparison of Stainless Steel With
Traditional Container Material-Aluminum:
Comparison of stainless steel with traditionally
used container (Aluminum) was done with the
container lids painted with black board paint. To
Type of Time Load in Average solar Average Average
container (no. of radiation in watt/m2time taken acceptability
containers) (minutes) scores
Initial Final
Table 1: Solar radiation, cooking time and acceptability scores for Al and SS in different loads of solar
cooking
Aluminum Before 1.00 PM 1 649 833 73 2.49
2 660 856 82 2.39
3 667 920 95 2.65
4 678 954 115 2.70
Stainless steel After 1.00 PM 1 680 862 77 2.81
2 672 910 92 3.01
3 686 961 102 3.12
4 694 998 132 2.98
Aluminum Before 1.00 PM 1 965 840 67 2.86
2 957 815 79 2.96
3 973 764 81 2.90
4 985 691 105 3.01
Stainless steel After 1.00 PM 1 990 825 73 3.07
2 971 810 85 3.21
3 960 705 98 3.51
4 995 684 118 3.35
199
EFFICACY OF STAINLESS STEEL AS COOKING UTENSIL MATERIAL FOR SOLAR COOKING
test the stainless steel as cooking utensil material
in solar cooking, the standardized rice water ratio
of 1:3 was kept in solar cookers in both stainless
steel and aluminum. The results of the experiment
are being given in table 1. The table gives obser-
vation on type of container material. Time of con-
ducting the experiments, loads in the solar cooker
i.e. cooking in 1, 2, 3 and 4 container, average
initial and average final radiation during the experi-
ments, average time taken and the acceptability
scores. From the table it can be seen that the
radiation in the forenoons was comparatively low
(initial radiation 649wt/m2-678wt/m2, final radiation
833 wt/m2-954wt/m2) whereas in the afternoons
the radiations were high and thus the impact of
same can be seen on cooking time. The intensity
of radiation saved 6-10 minutes in aluminum
container and 6-14 minutes in steel container.
In the forenoons, it can be observed that alu-
minum saved only 4 minutes in single container
load, 10 minutes in double container load, 7
minutes in 3 container load and 17 minutes in full
load, inspite of its better conduction qualities in
comparison to stainless steel. Similarly in the
afternoon also since the solar radiation was
higher; the time taken for solar cooking was a
little less in both the types of containers. Further,
a similar time difference was observed between
aluminum and stainless steel during both fore-
noons and afternoons observation. Thus, it can
be concluded that even when the radiation was
more or less equal, the stainless steel was only
taking an insignificant extra time in cooking. (The
higher average final radiation in case of stainless
steel was due to some extra cooking time in that
container).
When the cooked rice samples were given to
panel of judges, they rated the rice cooked in
stainless steel comparatively better, with an
average score ranging between 2.81-3.12 in the
forenoon as against the scores between 2.39-2.70
for rice in aluminum and in the afternoons. Also
the acceptability score for rice was higher for
stain-less steel (3.07 to 3.5) in comparison to
aluminum (2.86 to 3.01).
Thus, the following observations were made
on the basis of the experiments:
1. Solar cooking can be done in stainless steel.
2. Stainless steel took merely 4-17minutes extra
in the morning and about 6 to 13 minutes
extra in the afternoons.
3. The quality of cooked rice was rated better
by judges in stainless steel in comparison to
aluminum.
CONCLUSION
The experiments indicated that solar cooking
can be done in stainless steel, although the cook-
ing time in stainless steel was a little higher but
the acceptability scores were better for the finish-
ed product in it. The extra cooking time in steel
can be undermined looking in to the advantages
of its higher acceptance by the judges and conve-
nience in use, in comparison to aluminum.
The stainless steel is highly convenient to
use due to ease in its cleaning and maintenance.
Stainless steel being non-reactive metal, it is
possible to cook and store both acidic and non-
acidic food in it without affecting its quality and
acceptability. Stainless steel being non-corrosive
material will also have longer life than aluminum.
Other decorative flat bottom stainless steel uten-
sils can also be tried in solar cookers, which may
increase the possibility of making it ready to serve
container.
Fresh measures can be taken to popularize
solar cooker with stainless steel containers be-
cause while aluminum container as surveyed by
the researcher was highly non-popular material
and stainless steel was a highly popular material
which might enhance the popularity of the solar
cookers also.
REFERENCES
Jorm A 1996. Leading edge international research group
1996. from <http://www. turfax.org/ general/
aluminium.htm.> (Retrieved September 8, 2006).
Ismail SA 2001. Official Home Page of Bawarchi 2001.
Consumption of rice quarie <www.bawarchi.com>/
health/queries 4,html.25k. (Retrieved September 8,
2006).
Negi BS, Purohit I 2004. Energy conservation and
management prit.iitl.ac. in/dspace/bitstream/2074/
1417/1/negiexp2005.pdf (Retrieved September 18,
2006).
Sperber B 2002. A decentralized approach to renewable
energy production. Internet : <http://www. earth
summit 2002.org//> (Retrieved October 1, 2006).
