Physical properties of bread prepared from 90% wheat and 10% cassava composite flour were investigated using response surface methodology. A central composite rotatable experimental design with two factors and five levels was used. The independent variables were baking temperature and time. Thirteen baking trials were performed with five central points and eight non central points. The results showed that the crumb moisture, specific loaf volume, crumb hardness and overall acceptability values ranged from 33 - 39.6%, 3.80 - 4.8cm3/g, 63.00 - 70.25N and 6.2 - 8.1 respectively. There were significant differences (p< 0.05) in the physical properties of the bread samples and the physical properties were affected by the baking temperature and time. The bread samples baked at temperature of 195°C for 16.89 minutes were highly preferred by the panelists and the best processing conditions were baking temperature of 181.20°C at 24.18 minutes with desirability of 0.85. This research suggested that 10% inclusion of cassava in the production of bread would further increase the utilization of cassava flour, thereby promoting the economic value of the indigenous crop.
Bread is a convenient food because it is ready-to-eat, easy to carry round, moderate moisture content food, its taste is highly acceptable 1 and it is part of the major daily diet calorie intake of many people all over the world 2. It is a staple food that is prepared by baking dough of flour and water 3. In choosing the appropriate flour type for non-wheat baking, full consideration should be given to the realities of the local agricultural resources prevalent in the area. Nations all over the world have developed their own bread specialties based on their available agricultural resources 4. White bread is the most common type of bread produced in Nigeria and about 6.2 billion loaves are supplied by over 20,000 bakeries into Nigeria market annually 5. In recent years the consumption of wheat bread has increase tremendously in many developing nations including Nigeria which could be due to increase in population, urbanization and changing in food habit 6. Elemo et al. 5, reported that the recent annual value of wheat importation in Nigeria is N635 billion. To reduce the nation’s cost on importation of wheat and find wider application for the largely produced cassava roots, the Federal Government of Nigeria approved the use of composite cassava-wheat flour for baking by adding 10% cassava flour to wheat as reported by Shittu et al., 7. They also reported that the control of the baking parameters like baking temperature and time combination during baking as an engineering problem could be critical to the successful implementation of commercial flour baking technology 7.
Response surface methodology (RSM) is a collection of statistical and mathematical techniques used for development, improvement and optimization of processes or formulations 8, 9. It is used to examine the relative significance between a set of quantitative experimental factors and the response variable. Therefore, this study aimed in assessing the physical properties of bread from wheat-cassava composite flour using response surface methodology.
Cassava (Manihot esculenta) and wheat flour (Triticum spp) were purchased at Sabo Market, Ikorodu, Lagos State, Nigeria.
2.1. Production of Cassava FlourThe method described by Shittu et al., 7 was used. The cassava roots were manually peeled with knife and washed to remove sand and other dirt. The washed, peeled cassava roots were cut into round chips of uniform sizes. The wet chips were spread in stainless steel trays and sundried for 14 days. The dried chips were milled using attrition mill and sieved to separate coarse or fibrous particles from the fine flour and packaged in polyethylene films.
2.2. Production of BreadThe method described by Shittu, et al., 7 was used. The basic ingredients and the proportions required for the preparation of bread sample are 90% wheat and 10% cassava flour. Other ingredients include salt, yeast, sugar, EDC and water as shown in Table 1. Mixing was carried out manually according to the straight dough method. The dry ingredients, shortening and the activated yeast were added in a bowl and water and then kneaded until the dough was elastic and the required consistency was reached. After this, the dough was rounded and was kept in a bowl for the first proofing at the room temperature (30°C) for about 40 min. After the first proofing, the dough was punched and works lightly so that the excess gas could escape and the gas cells are redistributed. The dough was then shaped to fit lightly in greased bread pans. The dough was again kept for the final proofing for about 1 hour. Finally, after second proofing, the breads in pans were baked in oven at different experimental temperatures and time. After baking, the prepared bread samples were cooled for about 1 hour at room temperature and then analysis were carried out.
Response Surface Methodology comprising of a central composite design with two-factors and five-levels was used. The two independent variable factors used are baking temperature (X1) and baking time (X2) and the four dependent variables (responses) are crumb moisture (Y1), loaf specific volume (Y2), crumb hardness (Y3) and overall acceptability (Y4). Thirteen baking trials were performed with five central points and eight non central points. The coded values of the independent variables are presented in Table 2.
This was determined according to the method described by AACC 10 using the oven dry method, 1g of the sample (bread) was weighted into a silica dish; the silica dish with the sample was place in the oven at 105°C for 24 hours. It was cooled in the desiccator at room temperature. The content with the container was weighed and later placed back in the oven for another 24 hours to ensure complete drying. The cooling process in the desiccator was repeated before taking final weight.
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The specific volume analysis was determined by the modified method of Greene and Bovell-Benjamin 11. Samples were placed on the laboratory bench before the commencement of the analysis for few minutes. Beans were poured to cover the bottom of the borosilicate container of a known volume. The bread was placed in the container and the remainder of the beans was poured into the available space in the container using laboratory spatula. The leftover of the beans that were not required for the experiment were measured in a graduated cylinder and represented the volume of the bread.
The specific volume was obtained as a ratio of the volume of the bread to the weight of the bread.
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The hardness of the bread crumb was measured using Universal Testing Machine, Table Model (ERWEKA TBA 200), about 2.5x1.5 cm3 crumb slice was obtained from each loaf at the crumb center. Each slice was placed at the middle of a flat surface hardness tester receptacle. The plunger head was touched with the surface of the crumb slice. Thereafter, the plunger was driven 40 rpm into crumb until fracture. The maximum force require to cause failure (measured in N) is read off the dial gauge attached to the instrument.
2.5. Sensory EvaluationTwenty panelists accessed the attributes of the bread produced such as taste, colour, texture, appearance and overall acceptability using nine point hedonic scale, 1= dislike extremely and 9=like extremely 12.
2.6. Statistical AnalysisSecond order polynomial model was fitted to determine relationship between dependent variables, specific loaf volume (Y1), crumb moisture (Y2), crumb hardness (Y3), overall acceptability (Y4) and independent variable (X).
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Where β0, β1- β2, β11- β22 and β12 are regression coefficients for interception, linear, quadratic and interaction coefficients respectively, X1-X2 are coded independent variable and Y is the responses 13. An ANOVA test was carried out using design expert 6.0.8 (Stat-East Inc., Minneapolis, USA) to determine the significance at different levels (0.1%, 1% and 5%).
The effect of baking temperature and time on the crumb moisture content of bread samples are presented as contour plot in Figure 1. The crumb moisture content of the bread samples ranged from 33.0-39.6%. As the baking temperature and time increases the moisture content of the bread decreases. The model for the moisture content (R2=0.78) had a positive quadratic terms (baking temperature and time) and a positive linear terms. The crumb moisture content was significantly affected by X12 (quadratic effect of baking temperature). Moisture content is the amount or quantity of water presents in a food sample, the lower the moisture the longer the shelf-life. The amount of moisture in bread crumb has some implication on the mechanical 14 and keeping qualities 15.
The effect of baking temperature and time on the specific loaf volume of bread samples are presented as contour plot in Figure 2. The specific loaf volume of the bread samples ranged from 3.80-4.80 cm3/g. The specific loaf volume of the bread samples were influenced by baking temperature and time. As the baking temperature and time increases, the specific loaf volume of the bread samples decreases. The model for the specific loaf volume (R2=0.84) had a negative quadratic terms (baking temperature and time) and a positive linear terms. The specific loaf volume was significantly (P<0.05) affected by X12 and X22 (quadratic effect of baking temperature and time). All the bread samples are within the recommended standard for specific loaf volume (3.5-6.0 cm3/g) given by China Grain Product Research and Development Institute 16. Since the bread samples are produced from the same formulation, the variation of the specific loaf volume could be attributed mainly to different rate of gas evolution. The extent of starch gelatinization could be due to differences in baking temperature and time as reported by Eggleston et al., 17. Ragaee and Abdel-Aal 18, reported that higher loaf volume has positive effect on bread at retail end. Hence, decrease in loaf weight during baking is an undesirable economic quality to the bakers as consumers often get attracted to bread loaf with higher weight and volume.
The effect of baking temperature and time on the crumb hardness of bread samples are presented as contour plot in Figure 3. The hardness depended both on the baking temperature and time, and the values ranged from 63.0-70.25N. Hardness of the bread crumb increases with increase in baking temperature and time. The model for the crumb hardness (R2=0.88) had a positive quadratic terms (baking temperature and time) and a positive linear terms. The crumb hardness was significantly (P<0.05) affected by X12 and X22 (quadratic effect of baking temperature and time). Crumb hardness depends on crust thickness. The hardness test was used to determine the amount of energy that may be required to fracture a given volume of dried crumb. As the baking proceeded, the crust thickness increases with increase in baking temperature and time which could be due to the evaporation of moisture from the surface of the bread. Hardness is an important factor in bakery products and it is strongly related with the consumer’s perception of bread freshness 19.
The effect of baking temperature and time on overall acceptability of bread samples are presented as contour plot in Figure 4. The overall acceptability of the bread ranged from 6.2-8.1. From the sensory evaluation, it was noticed that the baking temperature and time affected the final bread quality. As the baking temperature and time decreases, the overall acceptability of the bread increases. The model for the specific loaf volume (R2=0.76) had a negative quadratic terms (baking temperature and time) and a negative linear terms. The overall acceptability was significantly affected by X12 (quadratic effect of baking temperature). Bread baked at 1950C for 16.89 minutes had the highest overall acceptability in terms of taste, colour, and texture, while the bread baked at 2100C for 35 minutes was least accepted in terms of taste, colour and texture.
The optimization conditions for the production of bread are presented as contour plot in Figure 5. The best conditions for the production of bread are baking temperature of 181.20°C at 24.18 minutes with desirability of 0.85, indicating that the bread produced from 90% wheat and 10% cassava flour are of good quality.
Response surface methodology was successful used to optimize the physical properties of bread produced from 90% wheat and 10% cassava flour. The baking temperature and time had a significant effect on the physical properties of the bread. The bread baked at 195°C for 16.89 minutes was highly preferred by the panelists. The best conditions for the production of bread are baking temperature of 181.20°C at 24.18 minutes with desirability of 0.85. In conclusion, the study showed that good quality bread could be produced from wheat-cassava composite flour without compromising the quality of the bread.
[1] | Edema, M.O. and Sanni, A.I. (2008). Functional properties of selected starter cultures for sour maize bread. Food Microbiology 25:616-625. | ||
In article | View Article PubMed | ||
[2] | Bureng, P.L. and Olatunji, O.O (1992). Wheatless bread development and extension. Federal International Institute Research Oshodi (FIIRO) publication. 37-38. | ||
In article | |||
[3] | Osuji, C.M. (2006). Importance and use of additives in bread making. A paper presented at a training workshop on the use of cassava/wheat composite flour and non bromated additives for making bread and other confectioneries. Held at Micheal Okpara University of Agriculture, Umudike. | ||
In article | |||
[4] | Edema, M.O., Sanni, L.O. and Sanni, A.I. (2005). Evaluation of maize-soybean flour blends for sour maize bread production in Nigeria. African Journal of Biotechnology 4(9) 911-918. | ||
In article | |||
[5] | Elemo, G.N., Osibanjo, A.A., Ibidapo, O.P, Ogunji, A.O., Asiru,W.B., Zakari, T and Olabanji, G.O (2017). Rheological characteristics and baking quality of flours from Nigerian grown wheat. African Journal of Food Science 11(12)/ 376-382. | ||
In article | View Article | ||
[6] | Malomo,S.A, Eleyinmi, A.F and Fashakin, J.B (2011): Chemical composition, rheological properties and bread making potentials of composite flours from breadfruit and wheat. African Journal of Food Science 5(7): 400-410. | ||
In article | |||
[7] | Shittu, T.A, Raji, A.O and Sanni LO (2007). Bread from composite cassava-wheat flour: I. Effect of baking time and temperature on some physical properties of bread loaf. Food Research International 40: 280-290. | ||
In article | View Article | ||
[8] | Malcolmson, L.J, Matsuo, R.R and Balshaw, R. (1993). Textural optimisation of spaghetti using response surface methodology: effects of drying temperature and durum protein level. Cereal Chemistry 70: 417-423. | ||
In article | |||
[9] | Turabi E, Sumnu, G and Sahin, S (2008). Optimization of baking of rice cakes in infrared-microwave combination oven by response surface methodology. Food & Bioprocess Technology 1 64-73. | ||
In article | View Article | ||
[10] | AACC, (2000). Approved Method of the American Association of Cereal Chemist. St Paul MN USA | ||
In article | |||
[11] | Greene, J.L and Bovell-Benjamin, A.C. (2004). Macroscopic and sensory evaluation of bread supplement with sweet potatoes flour. Journal of Food Science 69:167-173. | ||
In article | View Article | ||
[12] | Iwe, M. O. 2002: Sensory Method and Analysis. Published by Rojoint Communication Services (Ed.), Enugu. Pp 49, 72 | ||
In article | |||
[13] | Stat-Ease (2002). Design Expert 6.0.8, stat ease, Inc. 2012, Ease Hennepin Ave., suite 4&6 Minneapolis, MN 55 413. | ||
In article | |||
[14] | Zghal, M.C, Scanlon, M.G and Sapirstein, H.D (2002). Cellular structure of bread crumb and its influence on mechanical properties. Journal of Cereal Chemistry 36. 167-176. | ||
In article | View Article | ||
[15] | Defloor I, Nys, M and Delcour, J.A (1993). Wheat starch, cassava starch, and cassava flour impairment of the bread making potential of wheat flour. Cereal Chemistry. 70: 526-530. | ||
In article | |||
[16] | Lin, L., Liu, H., Yu, Y., Lin S.D and Mau, J (2009). Quality and antioxidant properties of buckwheat enhanced wheat bread. Journal of Food Chemistry 37: 461-467. | ||
In article | |||
[17] | Eggleston, G., Omoaka, P.E., and Arowosegbe, A.U. (1993). Flour starch and composite bread making quality of various cassava clones. Journal of the Science of Food and Agriculture, 62, 49-59. | ||
In article | View Article | ||
[18] | Ragaee, S., and Abdel-Aal, E.S.M. (2006). Pasting properties of starch and protein in selected cereals and quality of their products. Food Chemistry, 95, 9-18. | ||
In article | View Article | ||
[19] | Ahlborn, G.J, Pike O.A, Hendrix, S.B, Hess, W.M and Huber, C.S (2005). Sensory mechanical and microscopic evaluation of staling in low-protein and gluten-free breads. Cereal Chemistry 82 328-335. | ||
In article | View Article | ||
Published with license by Science and Education Publishing, Copyright © 2019 Peluola-Adeyemi O.A, Adepoju P.A and Lawal S.O
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[1] | Edema, M.O. and Sanni, A.I. (2008). Functional properties of selected starter cultures for sour maize bread. Food Microbiology 25:616-625. | ||
In article | View Article PubMed | ||
[2] | Bureng, P.L. and Olatunji, O.O (1992). Wheatless bread development and extension. Federal International Institute Research Oshodi (FIIRO) publication. 37-38. | ||
In article | |||
[3] | Osuji, C.M. (2006). Importance and use of additives in bread making. A paper presented at a training workshop on the use of cassava/wheat composite flour and non bromated additives for making bread and other confectioneries. Held at Micheal Okpara University of Agriculture, Umudike. | ||
In article | |||
[4] | Edema, M.O., Sanni, L.O. and Sanni, A.I. (2005). Evaluation of maize-soybean flour blends for sour maize bread production in Nigeria. African Journal of Biotechnology 4(9) 911-918. | ||
In article | |||
[5] | Elemo, G.N., Osibanjo, A.A., Ibidapo, O.P, Ogunji, A.O., Asiru,W.B., Zakari, T and Olabanji, G.O (2017). Rheological characteristics and baking quality of flours from Nigerian grown wheat. African Journal of Food Science 11(12)/ 376-382. | ||
In article | View Article | ||
[6] | Malomo,S.A, Eleyinmi, A.F and Fashakin, J.B (2011): Chemical composition, rheological properties and bread making potentials of composite flours from breadfruit and wheat. African Journal of Food Science 5(7): 400-410. | ||
In article | |||
[7] | Shittu, T.A, Raji, A.O and Sanni LO (2007). Bread from composite cassava-wheat flour: I. Effect of baking time and temperature on some physical properties of bread loaf. Food Research International 40: 280-290. | ||
In article | View Article | ||
[8] | Malcolmson, L.J, Matsuo, R.R and Balshaw, R. (1993). Textural optimisation of spaghetti using response surface methodology: effects of drying temperature and durum protein level. Cereal Chemistry 70: 417-423. | ||
In article | |||
[9] | Turabi E, Sumnu, G and Sahin, S (2008). Optimization of baking of rice cakes in infrared-microwave combination oven by response surface methodology. Food & Bioprocess Technology 1 64-73. | ||
In article | View Article | ||
[10] | AACC, (2000). Approved Method of the American Association of Cereal Chemist. St Paul MN USA | ||
In article | |||
[11] | Greene, J.L and Bovell-Benjamin, A.C. (2004). Macroscopic and sensory evaluation of bread supplement with sweet potatoes flour. Journal of Food Science 69:167-173. | ||
In article | View Article | ||
[12] | Iwe, M. O. 2002: Sensory Method and Analysis. Published by Rojoint Communication Services (Ed.), Enugu. Pp 49, 72 | ||
In article | |||
[13] | Stat-Ease (2002). Design Expert 6.0.8, stat ease, Inc. 2012, Ease Hennepin Ave., suite 4&6 Minneapolis, MN 55 413. | ||
In article | |||
[14] | Zghal, M.C, Scanlon, M.G and Sapirstein, H.D (2002). Cellular structure of bread crumb and its influence on mechanical properties. Journal of Cereal Chemistry 36. 167-176. | ||
In article | View Article | ||
[15] | Defloor I, Nys, M and Delcour, J.A (1993). Wheat starch, cassava starch, and cassava flour impairment of the bread making potential of wheat flour. Cereal Chemistry. 70: 526-530. | ||
In article | |||
[16] | Lin, L., Liu, H., Yu, Y., Lin S.D and Mau, J (2009). Quality and antioxidant properties of buckwheat enhanced wheat bread. Journal of Food Chemistry 37: 461-467. | ||
In article | |||
[17] | Eggleston, G., Omoaka, P.E., and Arowosegbe, A.U. (1993). Flour starch and composite bread making quality of various cassava clones. Journal of the Science of Food and Agriculture, 62, 49-59. | ||
In article | View Article | ||
[18] | Ragaee, S., and Abdel-Aal, E.S.M. (2006). Pasting properties of starch and protein in selected cereals and quality of their products. Food Chemistry, 95, 9-18. | ||
In article | View Article | ||
[19] | Ahlborn, G.J, Pike O.A, Hendrix, S.B, Hess, W.M and Huber, C.S (2005). Sensory mechanical and microscopic evaluation of staling in low-protein and gluten-free breads. Cereal Chemistry 82 328-335. | ||
In article | View Article | ||