Effect of Sweet Potato Flour on Quality of Cookies Shazia Saeed ...

<strong>Effect</strong> <strong>of</strong> sweet potato flour on quality <strong>of</strong> cookies
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EFFECT OF SWEET POTATO FLOUR ON QUALITY
OF COOKIES
Shazia Saeed, Muhammad Mushtaq Ahmad, Humaira Kausar,
Saima Parveen, Sharoon Masih and Abdus Salam *
ABSTRACT
This study was carried out at Food Technology Section, Post Harvest Research
Centre, AARI, Faisalabad to investigate effect <strong>of</strong> replacement <strong>of</strong> wheat flour
with sweet potato flour on quality <strong>of</strong> cookies. <strong>Sweet</strong> potato flour, composite
flours and cookies were analyzed for colour changes and other physical and
sensory attributes. <strong>Sweet</strong> potato flour was supplemented at proportions (5, 10,
15, 20 and 25%) with plain wheat flour in standard formulations <strong>of</strong> cookies. The
addition <strong>of</strong> sweet potato flour lowered the width <strong>of</strong> cookies from 282.00 to
264.00mm among treatments while thickness was also decreased from 68.90 to
65.00mm. Ultimately the value <strong>of</strong> spread factor also reduced from 41.47 to 40.00
with increasing level <strong>of</strong> sweet potato flour. No significant difference for
physical parameters <strong>of</strong> cookies was observed during storage. The colour value
for cookies i.e. L*, a* and b* varied from 65.26 to 61.82, 20.37 to 16.95 and 28.89
to 25.95, respectively. Sensory evaluation revealed that level <strong>of</strong> sweet potato
flour beyond 10 percent lowered the overall acceptability. Within treatments
maximum score for over all acceptability was observed for T 2 (8.60) having 10
percent sweet potato flour followed by T 3 (8.40) containing 15 percent sweet
potato flour at 0 day. T 2 was also found to be the most acceptable with respect
to organoleptic characteristics especially taste and flavour developed during
baking as compared to other treatments during storage.
KEYWORDS: Ipomola batatas; flour; cookies, keeping quality; Pakistan.
INTRODUTION
<strong>Sweet</strong> potato (Ipomoea batatas L.) is an important alternative source <strong>of</strong>
carbohydrates and attains fourth place after rice, corn and cassava.
Presently, this crop is considered as having low economic value but it has
significant social importance. It is most versatile for snack food, but it is used
as staple food or as a rice substitute in many countries (28).
*Food Technology Section, Post Harvest Research Centre, Ayub Agricultural Research
Institute, Faisalabad. Email:ftaari@yahoo.com
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<strong>Sweet</strong> potato has a large potential to be used as food in developing nations
with limited resources because <strong>of</strong> short maturity time, ability to grow under
diverse climatic conditions and on less fertile soil. <strong>Sweet</strong> potato flour can
serve as a source <strong>of</strong> energy and carbohydrates, beta carotene (pro-vitamin
A), minerals (Ca, P, Fe and K) and dietary fibre which can add natural
sweetness, colors and flavour to processed food products (24, 27).
Traditionally cookies are made from wheat flour but small quantities <strong>of</strong> other
cereal flours or starches can also be added to give special flavour or
structural properties. In recent years the interest in high fibre content in foods
has greatly increased. High dietary fibre supplemented cookies have been
prepared by replacing wheat flour with cereal by-products like corn bran, rice
bran or barley husk (4, 8, 22).
Most <strong>of</strong> the research has been focused on the development <strong>of</strong> new products
using sweet potato flour rather than on efficient methods to produce and
store the flour (10). Hagenimana et al. (7) reported that addition <strong>of</strong> orangefleshed
sweet potato in buns, chapattis and mandazis greatly increased the
content <strong>of</strong> total carotenoids in these products. Addition <strong>of</strong> various proportion
<strong>of</strong> sweet potato flour in wheat flour can increase the nutritive values in terms
<strong>of</strong> fibre and carotenoids. This also helps lower the gluten level and prevent
from coeliac disease (23). Blending <strong>of</strong> sweet potato flour with wheat flour can
be used for production <strong>of</strong> bakery goods with improved functional properties
and reduced retro-graduation, staling rate and production time (1) and also
helps in making a good baking product with increased economic value.
Baking industry in Pakistan is flourishing day by day. A wide variety <strong>of</strong> baked
goods is available in market to fulfill consumer demand for nutritional
requirement. Now people are becoming more conscious about their health
and nutrition. They require foods that are convenient with good taste,
reasonable price and carry favorable nutritional image. Besides other baked
products, cookies are one <strong>of</strong> the most popular bakery products, widely
consumed due to its ready-to-eat nature, good nutritional quality, low cost
and longer shelf life that has also been enriched with dietary fibre (3).
Biscuits are ideal for their nutritional value, palatability, compactness and
convenience. These are also important food reserves for exploration, in war
or flood and as an aid for the famished people. Many travelers and explorers
have, over the centuries, been grateful to humble cookies for these
properties. Indeed, cookies still form a significant component <strong>of</strong> many
emergency food supplies.
The present research was conducted to find out most suitable proportion <strong>of</strong>
sweet potato flour and wheat flour for cookies preparation keeping in view its
physical and sensory parameters.
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MATERIALS AND METHODS
This study was conducted in Food Technology Section, Post Harvest
Research Centre, AARI, Faisalabad, Pakistan during the year 2010. <strong>Sweet</strong>
potato and other ingredients for the preparation <strong>of</strong> cookies e.g. wheat flour,
sugar, shortening, baking powder and eggs were purchased from local
market. <strong>Sweet</strong> potato roots were washed and trimmed to make them free
from soil and other foreign materials, rotten part or insect damage, etc.
These were peeled and cut into thin slices manually. Slices were then
immersed in solution containing potassium meta-bisulphite (0.5%) for 15
minutes. <strong>Sweet</strong> potato slices were dined on perforated wooden trays in a
tunnel dehydrator at 60 o C till 10 percent moisture content. The dried chips
were milled into flour using the grinder and passed through 80 mesh sieve to
obtain flour <strong>of</strong> uniform size. Flow diagram for preparation <strong>of</strong> sweet potato
flour cookies is given below:-
SWEET POTATO
GRADING AND WASHING
PEELING
SLICING
TREATMENT
DRYING (55°C)
GRINDING
SIEVING (size 80 mesh)
INGREDIENTS MIXING
KNEADING
SHEETING
CUTTING
BAKING
PACKING and STORAGE
Fig.1. Flow diagram for preparation <strong>of</strong> sweet potato flour cookies
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Wheat flour and sweet potato flour were used in different proportions viz.
100:0 (T 0 ), 95:5 (T 1 ), 90:10 (T 2 ), 85:15 (T 3 ), 80:20 (T 4 ) and 75:25 (T 5 ).
Cookies were prepared with some modifications according to the method as
described in AACC (3) with the formulation as given in Table 1.
Table 1. Formulation for cookies.
Ingredients
Wheat flour
Sugar
Shortening
Baking powder
Eggs
Water
Quantity
200 g
100 g
100 g
3 g
1 (in No)
15 – 20 mL
After weighing the ingredients accurately, fat and sugar were creamed in a
mixer with a flat beater for two minutes at slow speed, followed by addition <strong>of</strong>
eggs. Creaming continued till foaming was occurred. The wheat flour, baking
powder and water were added to the creaming mass and mixed to a
homogeneous mixture for five miniutes at high speed. Finally, flour containing
various proportions <strong>of</strong> sweet potato flour, which had been sieved twice with
baking powder was added and mixed for three minutes at medium speed.
The dough was then sheeted to a thickness <strong>of</strong> 3.00 mm with the help <strong>of</strong> a
rolling pin and aluminum frame <strong>of</strong> standard height. The cookies were cut with
a cookies die <strong>of</strong> 35 mm diameter and transferred to a lightly greased baking
tray at a proper distance. The cookies were baked at 218 o C in baking oven
for 10-12 minutes. After baking, cookies were cooled at room temperature
and packed in air tight polythene bags for further storage studies.
Proximate analysis <strong>of</strong> sweet potato flour and plain wheat flour
<strong>Sweet</strong> potato flour and plain wheat flour were analyzed for moisture, protein,
ash, fat and crude fibre and nitrogen free extract, according to the methods
described in AACC (1).
Colour (Lab)
The colour values <strong>of</strong> flour and cookies were measured using the L*, a* and b*
colour space (CIE-LAB Space) with Color Tech-PCM (USA). The L* value
indicates (lightness), a* and b* values are chromaticity coordinates (a* from
red (+) to green (-) and b*, from yellow (-) to blue (-).
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Physical analysis <strong>of</strong> cookies
The packed cookies, prepared from different levels <strong>of</strong> sweet potato flour were
placed at room temperature. Physical characteristics <strong>of</strong> cookies like width,
thickness and spread factor were measured fortnightly for 90 days storage
according to the methods described in AACC (3).
Width (W): Width <strong>of</strong> cookies was measured by placing six cookies
horizontally (edge to edge) and rotated at 90 o angle for duplicate reading.
Thickness (T): The thickness <strong>of</strong> cookies was measured by placing six
cookies on one another and the duplicate reading was recorded.
Spread factor (SF): The spread factor was calculated according to the
formula SF = (W/T x CF) x 10 where CF=Correction factor at constant
atmospheric pressure (10.0 in this case).
Sensory evaluation
Characteristics like colour, flavour, taste and overall acceptability were
evaluated by a panel <strong>of</strong> five semi-trained judges selected from Food
Technology Section, AARI, Faisalabad. Sensory characteristics like colour,
flavour, taste and overall acceptability were measured at 15 days interval
upto 90 days, according to the procedure described by Meilgaard et al. (14).
Statistical analysis
The data obtained were statistically analyzed for analysis <strong>of</strong> variance
(ANOVA) by using 2-factorial completely randomized design using LSD at
P≤0.05 according to the method described by Steel et al. (21).
RESULTS AND DISCUSSION
Proximate analysis <strong>of</strong> sweet potato flour and plain wheat flour
Proximate analysis (Table 2) indicated that moisture content <strong>of</strong> sweet potato
flour was 8.7 percent with high fibre (8.5%) but very low protein contents
(3.1%). The ash percentage in sweet potato flour was recorded upto 2.1
percent with 76.39 percent nitrogen free extract (NFE). These results are in
close agreement with findings <strong>of</strong> Singh et al. (20) who have reported 8.7
percent moisture contents, 2.3 percent protein, 9.4 percent fibre and 1.56
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Table 2. Proximate analysis <strong>of</strong> sweet potato flour and plain wheat flour.
Sr. No Composition (%) <strong>Sweet</strong> potato flour Plain wheat flour
1 Moisture 8.7 11.9+ 0.1
2 Protein 3.1 11 + 0.07
3 Fat 1.21 1.68 + 0.06
4 Fibre 8.5 0.07 + 0.08
5 Ash 2.1 0.68 + 0.01
6 NFE 76.39 74.67 + 0.1
percent ash in sweet potato flour. Mebpa et al. (13) also reported similar
results regarding composition <strong>of</strong> plain wheat flour i.e. 11.31 percent moisture,
12.86 percent protein, 1.40 percent lipids, 0.82 percent crude fat and 0.46
percent ash.
Colour analysis <strong>of</strong> flour blends and cookies
<strong>Effect</strong> <strong>of</strong> sweet potato flour on colour values <strong>of</strong> flour blends and cookies was
significant (Tables 3). L* value <strong>of</strong> flour blends decreased significantly from
95.75 to 84.96 with increasing the proportion <strong>of</strong> sweet potato flour.
However this value decreased from 65.26 to 61.82 in the cookies. The value
<strong>of</strong> a* increased from 2.62 to 5.92 with increasing the proportion <strong>of</strong> sweet
potato flour in flour blends. In cookies the results showed a decline <strong>of</strong> a*
value from 20.37 to 16.95 (Table 3). It indicated that redness in flour blends
increased with the addition <strong>of</strong> sweet potato flour while in cookies redness
decreased. The b* value which shows yellowness <strong>of</strong> flour increased
significantly from 9.84 to 14.65 while in cookies this value reduced from
28.89 to 25.95 with increasing the proportion <strong>of</strong> sweet potato flour (Table 3).
The yellow-orange colour <strong>of</strong> sweet potato flour was due to the presence <strong>of</strong>
carotenoid pigments, which affected the red-green chromaticity (24). The
results coincide with those <strong>of</strong> Singh et al. (19) who observed similar pattern in
colour changes in the preparation <strong>of</strong> sweet potato flour incorporated cookies
at different proportions.
Table 3. <strong>Effect</strong> <strong>of</strong> sweet potato flour on color <strong>of</strong> flour blends and cookies.
Color values <strong>of</strong> flour blends Color values <strong>of</strong> cookies
Wheat flour sweet: L* a* b* L* a* b*
potato flour
100:0 95.75d 2.62a 9.84a 65.26d 20.37d 28.89d
95:5 93.69c 3.25b 10.42ab 64.51c 20.08d 28.26d
90:10 90.78ab 3.98bc 11.87b 63.71bc 19.25cd 27.92cd
85:15 89.71bc 4.56c 12.92c 63.05bc 18.76c 27.43c
80:20 87.94b 5.03cd 13.32cd 62.35b 17.26b 26.65b
75:25 84.96a 5.92d 14.65d 61.82a 16.95a 25.95a
The values denoted by different letters in the same column are significantly different
(p

<strong>Effect</strong> <strong>of</strong> sweet potato flour on quality <strong>of</strong> cookies
531
The flour blends were analyzed for colour changes in each treatment. It was
observed that with gradual increase in sweet potato flour there was a
reduction in L* value while a* and b* values were gradually increased with the
addition <strong>of</strong> sweet potato flour. Similar results are also found by Singh et al.
(19) while studying effect <strong>of</strong> incorporating sweet potato flour in wheat flour on
quality characteristics <strong>of</strong> cookies.
Physical characteristics
Width (W): Analytical results indicated (Fig. 1) that different levels <strong>of</strong> sweet
potato flour showed significant effect on the width <strong>of</strong> cookies. A decreasing
trend was found with the increase <strong>of</strong> sweet potato flour level. At 0 day
storage, T 0 exhibited maximum width (288mm) followed by T 1 (282mm), while
T 5 exhibited minimum width (264mm) followed by T 4 (269mm). It is clear that
enhancement in level <strong>of</strong> sweet potato flour significantly decreased the width
<strong>of</strong> cookies which is attributed to an increase in fibre contents due to addition
<strong>of</strong> sweet potato flour, a rich source <strong>of</strong> dietary fibre.
Width (mm )
290
285
280
275
270
265
260
255
250
0 15 30 45 60 75 90
T0 (WF100%:SPF 0%)
T1 (WF95%:SPF 5%)
T2 (WF90%:SPF 10%)
T3 (WF85%:SPF 15%)
T4 (WF80%:SPF 20%)
T5 (WF75%:SPF 25%)
Storage Days
Fig. 1. <strong>Effect</strong> <strong>of</strong> treatments and storage on width <strong>of</strong> cookies
However, storage exhibited non-significant effect on the width <strong>of</strong> cookies.
Sharif et al. (17) prepared fibre and mineral enriched de-fatted rice bran
supplemented cookies. They observed a decreasing trend in width from
44.15 to 36.53mm with percent increase in rice bran incorporation. Cookies
baked from flours with lipids have smaller diameters than those baked from
un-extracted flours. So, it can be inferred that due to smaller fat content
(1.21%) in sweet potato flour than s<strong>of</strong>t wheat flour (typically 2%), diameter
and width <strong>of</strong> cookies decreased with an increase in sweet potato flour
proportion (15).
Thickness (T): The thickness <strong>of</strong> cookies decreased significantly from 68.9 to
65.00mm among treatments, with increasing percentage <strong>of</strong> sweet potato
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flour (Fig. 2). The results revealed that at 0 day T 0 and T 1 exhibited maximum
thickness (68.10mm) and (68.90mm) respectively, followed by T 3 (67.00mm)
while T 5 exhibited minimum thickness 65.00mm. It is evident that increased
level <strong>of</strong> sweet potato flour significantly decreased the thickness <strong>of</strong> cookies.
Thickness (mm)
70
69
68
67
66
65
64
63
62
0 15 30 45 60 75 90
Storege Days
T0 (WF100%:SPF 0%)
T1 (WF95%:SPF 5%)
T2 (WF90%:SPF 10%)
T3 (WF85%:SPF 15%)
T4 (WF80%:SPF 20%)
T5 (WF75%:SPF 25%)
Fig. 2. <strong>Effect</strong> <strong>of</strong> treatments and storage on thickness <strong>of</strong> cookies
The results for storage study had shown non-significant effect on cookies
thickness which decreased from 68.9 to 64.65mm during 0 to 90 days
interval. These results are in close agreement with the findings <strong>of</strong> Singh et al.
(19) who studied the effect <strong>of</strong> incorporating sweet potato flour with wheat
flour on quality characteristics <strong>of</strong> cookies. They observed that thickness <strong>of</strong>
cookies decreased from 48 to 40mm with increase in sweet potato flour
percentage.
Spread factor (S): The results pertaining to spread factor <strong>of</strong> cookies
revealed a reduction in spread factor from 42.35mm (T 1 ) to 40.00mm (T 5 )
among treatments as the level <strong>of</strong> sweet potato flour was increased (Fig. 3).
At 0 day T 0 exhibit maximum spread factor 42.35 mm while T 5 exhibited
minimum spread factor (40.00 mm). Remaining treatments T 1 (41.47 mm), T 2
(41.34 mm) T 3 (40.89 mm) and T 4 (40.75) also followed the same decreasing
trend <strong>of</strong> spread factor. The results elucidated that treatments had significant
effect on spread factor <strong>of</strong> cookies due to replacement <strong>of</strong> different levels <strong>of</strong>
sweet potato flour with plain wheat flour. However, storage exhibited nonsignificant
effect on cookies spread factor.
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Spread Factor
43.5
43
42.5
42
41.5
41
40.5
40
39.5
39
38.5
38
0 15 30 45 60 75 90
Storage Days
T0 (WF100%:SPF 0%)
T1 (WF95%:SPF 5%)
T2 (WF90%:SPF 10%)
T3 (WF85%:SPF 15%)
T4 (WF80%:SPF 20%)
T5 (WF75%:SPF 25%)
Fig. 3. <strong>Effect</strong> <strong>of</strong> treatments and storage on spread factor <strong>of</strong> cookies
Hussain et al. (9) also found that supplementation <strong>of</strong> 30 percent flaxseed
flour reduced the spread factor from 48.49 to 47.71mm. It has been
established that cookies spread is strongly correlated to the water absorption
capacities <strong>of</strong> the flour (26). Since the water absorption capacity <strong>of</strong> sweet
potato flour (2.375ml/g) is higher than that <strong>of</strong> wheat flour (1 ml/g), rapid
partitioning <strong>of</strong> free water to hydrophilic sites <strong>of</strong> sweet potato flour is
presumed to be higher than wheat flour. Therefore, it can be concluded
that sweet potato flour additions limit the spreading <strong>of</strong> cookies. Rapid
partitioning <strong>of</strong> free water to hydrophilic sites during mixing increases dough
viscosity, thereby limiting cookie spread.
Sensory evaluation
Cookies prepared under different treatments were stored at ambient
temperature for 90 days. These were evaluated for colour, flavour, taste,
texture and overall acceptability at 15 days interval by a panel <strong>of</strong> judges. The
results are given below:-
Colour: The scores regarding colour ranged from 8.6 to 6.4 (Fig. 4) for 90
days <strong>of</strong> storage. T 2 (10% sweet potato flour) was preferred by the judges
because it gave the desired colour to the cookies which distinguished it from
others. However, other treatments were also acceptable.
Storage studies indicated a significant decrease in mean color score <strong>of</strong>
cookies. There was darkening in colour during storage that attained lower
color scores in all treatments. The mean colour scores were gradually
decreased with the passage <strong>of</strong> time.
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10
9
8
S c ores for c olor
7
6
5
4
3
2
1
0
0 15 30 45 60 75 90
T0 (W F 100% :S P F 0% )
T1 (W F 95% :S P F 5% )
T2 (W F 90% :S P F 10% )
T3 (W F 85% :S P F 15% )
T4 (W F 80% :S P F 20% )
T5 (W F 75% :S P F 25% )
S tora g e pe riod
Fig. 4: <strong>Effect</strong> <strong>of</strong> Storage on color <strong>of</strong> sweet potato flour cookies
These results are in close agreement with the findings <strong>of</strong> Elahi (6) who
reported a gradual decrease in colour <strong>of</strong> biscuits made from composite flours
<strong>of</strong> wheat and gram during storage <strong>of</strong> 90 days. Pasha et al., (16) also
observed the same pattern <strong>of</strong> decrease in colour during 60 days storage <strong>of</strong>
cookies. The deterioration in colour <strong>of</strong> the biscuits might be due to the
absorption <strong>of</strong> moisture from the atmosphere and as a result <strong>of</strong> Maillard’s
reaction, biscuits possessed higher amounts <strong>of</strong> protein and sugar (13).
Flavour: Maximum mean scores <strong>of</strong> judges was recorded in T 2 (8.20)
followed by T 3 , while minimum score was observed in T 5 (6.4) followed by T 4
at 90 days storage interval (Fig. 5).
10
9
S c ores for flavour
8
7
6
5
4
3
2
T0 (W F 100% :S P F 0% )
T1 (W F 95% :S P F 5% )
T2 (W F 90% :S P F 10% )
T3 (W F 85% :S P F 15% )
T4 (W F 80% :S P F 20% )
1
T5 (W F 75% :S P F 25% )
0
0 15 30 45 60 75 90
S tora g e period
Fig. 5. <strong>Effect</strong> <strong>of</strong> Storage on flavour <strong>of</strong> sweet potato flour cookies
The storage trend showed a gradual decline in flavor <strong>of</strong> cookies which might
be attributed to absorption <strong>of</strong> moisture that resulted in fat oxidation. Similar
results were also recorded by Sharif et al. (17). However after 90 days <strong>of</strong>
storage all the cookies remained acceptable.
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<strong>Effect</strong> <strong>of</strong> sweet potato flour on quality <strong>of</strong> cookies
535
Taste: The results revealed that all cookies obtained varying scores for taste.
However, maximum score was observed in T 2 (8.4) while T 5 (7.00) had
minimum scores (Fig. 6) at 0 day. Means for taste <strong>of</strong> cookies revealed that T 3
(8.00) and T 4 (7.8) were at par with each other but differed significantly from
other treatments.
S c ores for tas te
9
8
7
6
5
4
3
2
1
0
0 15 30 45 60 75 90
S tora g e period
T0 (WF 100% :S P F 0% )
T1 (WF 95% :S P F 5% )
T2 (WF 90% :S P F 10% )
T3 (WF 85% :S P F 15% )
T4 (WF 80% :S P F 20% )
T5 (WF 75% :S P F 25% )
Fig. 6. <strong>Effect</strong> <strong>of</strong> Storage on taste <strong>of</strong> sweet potato flour cookies
Elahi (6) also found a decrease in mean score for taste from 6.62 to 5.81
after 90 days storage in biscuits prepared from composite flour. Variation in
taste is due to the variable percentage <strong>of</strong> sweet potato flour used in cookies
preparation while decrease in taste during storage may occur due to the
rancidity <strong>of</strong> fat.
Overall acceptability: Overall acceptability was determined on the basis <strong>of</strong>
quality scores obtained for colour, flavour and taste <strong>of</strong> cookies. The results
(Fig. 7) disclosed that judges placed T 2 (10% sweet potato flour) at first
position (8.60 scores) and T 5 at bottom (7.40) at 0 day.
S cores for overall ac c eptability
10
9
8
7
6
5
4
3
2
1
0
0 15 30 45 60 75 90
T0 (WF 100% :S P F 0% )
T1 (WF 95% :S P F 5% )
T2 (WF 90% :S P F 10% )
T3 (WF 85% :S P F 15% )
T4 (WF 80% :S P F 20% )
T5 (WF 75% :S P F 25% )
S tora g e period
Fig. 7. <strong>Effect</strong> <strong>of</strong> Storage on overall acceptability <strong>of</strong> sweet potato flour cookies
During storage an identical decreasing pattern in scores for overall
acceptability was noted in all samples. The highest score (8.60) was noted at
0 day in T 2 which decreased upto 7.20 after 90 days <strong>of</strong> storage but cookies
remained acceptable at the end <strong>of</strong> storage period. The decrease in overall
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acceptability was due to decrease in colour, flavour, taste, texture and
crispness. Sharif et al. (18) have also reported a decreasing trend in
overall acceptability from 7.24 to 6.45 after 45 days storage <strong>of</strong> rice bran
supplemented cookies.
CONCLUSION
It is concluded that a proportion <strong>of</strong> 90:10 <strong>of</strong> plain wheat flour and sweet
potato flour produced good results without any adverse effect on physical
and sensory characteristics <strong>of</strong> cookies. It was also noted that sweet potato
flour improved the flavour and texture <strong>of</strong> cookies and can significantly
improve the dietary fibre and mineral contents <strong>of</strong> the product. These results
can be further applied for the development <strong>of</strong> nutritious high fiber and low
gluten cookies.
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