Nutrition & Food Science

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National Food Technology Research Centre, Kanye, Botswana. Abstract. Purpose – This paper seeks to examine the production of wheatless bread from acha ...

Nutrition & Food Science Emerald Article: Preliminary study into the production of non-wheat bread from acha (Digitaria exilis) Victoria A. Jideani, Rasheedat Alamu, Israel A. Jideani

Article information: To cite this document: Victoria A. Jideani, Rasheedat Alamu, Israel A. Jideani, (2007),"Preliminary study into the production of non-wheat bread from acha (Digitaria exilis)", Nutrition & Food Science, Vol. 37 Iss: 6 pp. 434 - 441 Permanent link to this document: http://dx.doi.org/10.1108/00346650710838090 Downloaded on: 08-02-2013 References: This document contains references to 14 other documents Citations: This document has been cited by 1 other documents To copy this document: [email protected] This document has been downloaded 225 times since 2007. *

Users who downloaded this Article also downloaded: * Victoria A. Jideani, Rasheedat Alamu, Israel A. Jideani, (2007),"Preliminary study into the production of non-wheat bread from acha (Digitaria exilis)", Nutrition & Food Science, Vol. 37 Iss: 6 pp. 434 - 441 http://dx.doi.org/10.1108/00346650710838090 Victoria A. Jideani, Rasheedat Alamu, Israel A. Jideani, (2007),"Preliminary study into the production of non-wheat bread from acha (Digitaria exilis)", Nutrition & Food Science, Vol. 37 Iss: 6 pp. 434 - 441 http://dx.doi.org/10.1108/00346650710838090 Victoria A. Jideani, Rasheedat Alamu, Israel A. Jideani, (2007),"Preliminary study into the production of non-wheat bread from acha (Digitaria exilis)", Nutrition & Food Science, Vol. 37 Iss: 6 pp. 434 - 441 http://dx.doi.org/10.1108/00346650710838090

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Preliminary study into the production of non-wheat bread from acha (Digitaria exilis) Victoria A. Jideani and Rasheedat Alamu

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Department of Food Science and Technology, Federal Polytechnic, Bauchi, Nigeria, and

Israel A. Jideani National Food Technology Research Centre, Kanye, Botswana Abstract Purpose – This paper seeks to examine the production of wheatless bread from acha flour and to determine consumer acceptability of the product. Design/methodology/approach – Wheatless bread was baked from acha (Digitaria exilis) and Irish potato starch blends of 80:20 respectively with varying (1-4 per cent) quantity of carboxymethylcellulose (CMC). The loaves were assessed for loaf volume (LV) and specific loaf volume (SLV) as well as consumer acceptability. Findings – The addition of CMC gave an increase in LV of 40.0 per cent in acha bread (AB) with 1 per cent CMC to 59.5 per cent in AB with 4 per cent CMC. The SLV of the acha loaves did not differ significantly from one another. There were significant differences (p < 0.05) between AB without CMC, AB with 1-3 per cent CMC and wheat bread in appearance, crust colour, crumb texture, crumb colour and general acceptability (p < 0.05). However, there was no significant difference between the AB with 4 per cent CMC and wheat bread in crumb texture, crumb colour and general acceptability. AB with 4 per cent CMC compared favourably with wheat bread in sensory characteristics. Research limitations/implications – This work was a preliminary work to determine the possibility of producing bread with acha. Further research will investigate the functional and nutritional qualities of AB with 4 per cent CMC found to be comparable with wheat bread. Practical implications – The study demonstrated the possibility of producing AB using CMC. Originality/value – Acha has been identified as a major food for diabetic patients in Nigeria by medical practitioners. The AB developed will be of great benefit to countless diabetic patients in Nigeria. Keywords Food products, Starches, Cereal foods Paper type Research paper

Nutrition & Food Science Vol. 37 No. 6, 2007 pp. 434-441 # Emerald Group Publishing Limited 0034-6659 DOI 10.1108/00346650710838090

Introduction Bread is a food made by baking a mixture of wheat flour, water, salt, sugar and yeast. It is also a food made from wide variety of plant substances that are ground into flour, mixed with water into dough and then usually baked into loaves or cakes (Encyclopedia Americana, 1995). The principal ingredient of bread is flour milled from wheat grain. When wheat flour is mixed with water (3:1) and kneaded thoroughly, cohesive viscoelastic dough is formed. During breadmaking, this extensible and rubbery mass is able to hold the gas produced by fermenting yeast without tearing due to unique proteins in the wheat flour. The protein primarily responsible for dough formation is a heterogeneous mixture of gliadins and glutenins known as gluten (Lovis, 2003). As a result, the dough piece is caused to increase in size, producing the light aerated product with typical of leavened bread. The proteins of other cereals apart from rye, to a lesser extent, do not have the capacity to form gluten. Most research on the development of gluten-free yeast bread has utilized wheat starch as a replacement for wheat flour (Ranhotra et al., 1975). However, many

individuals are sensitive to the gliadin fraction of gluten protein in wheat starch. An alternative starch from Irish potatoes could be used. Irish potato starch has a much higher viscosity than any other commercially available starches (Alexander, 1995). Wheatless or gluten-free breads require a gluten replacement to provide structural and gas retaining properties in the dough. A number of gums have been used individually and in combination, as gluten replacement with ranging degree of success (Ranhotra et al., 1975). These gums include xanthan gum, carboxymethylcellulose (CMC) gum, hydroxypropylmethylcellulose gum and others. CMC increases batter to encapsulate gas evolved by fast acting leavening agents which result in a higher volume and improved texture (Dziezak, 1991). Acha is grown for grains in Nigeria and some African countries and may be boiled like rice. Acha grain can also be ground into flour to produce cookie or biscuits (Obafunmi et al., 2001). It is thought that bread could be baked from acha (Digitaria exilis) flour. Acha has been identified as a major food for diabetic patients in Nigeria (Jideani, 1999) by medical practitioners. It is of interest to develop acha bread (AB) that will be of great benefit to teaming number of diabetic patients in Nigeria. Our objective was to produce wheatless bread from acha flour and determine consumer acceptability of the product.

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Materials and methods Sources of material Acha grain (Digitaria exilis), Irish potatoes (Solanum tuberosum), salt, sugar, yeast and oil were purchased from a local market in Bauchi, Bauchi State, Nigeria. The CMC powder was purchased from a local market in Kaduna, Kaduna State, Nigeria. Production of acha flour Acha flour was produced as outlined in Figure 1. The acha grains were cleaned by winnowing, washed and de-stoned using two calabashes. The grains were drained and then dried in the cabinet dryer at 60 C for 3 h. The dried grains were milled using a hammer milling machine and sieved through 0.165 mm aperture sieve size. The flour obtained was packaged in a low density polyethylene bag and stored in a cool dry place until needed.

Figure 1. Acha flour production process

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Extraction of starch from Irish potatoes The method of Okaka (1997) was adopted for the extraction of starch from Irish potato (Figure 2). The Irish potatoes were sorted, washed and peeled using the peeling machine. The peeled potatoes were diced and wet milled using 2 per cent sodium metabisulphite solution. The potato pulp was sieved using 0.315 mm sieve aperture. The filtrate was allowed to stand undisturbed for 5 h and the supernatant decanted. The sediment (starch) was dried in a cabinet drier at 60 C for 5 h. The dried starch was milled and sieved with 0.165 mm sieve size. The starch was packaged in a low density polyethylene bags and stored in a cool dry place until required. Production of AB The method of Ylimaki et al. (1988) for wheatless bread was modified and used for the production of AB (Figure 3). A fraction of the sugar (35 per cent) was dissolved in 80 per cent of the warm water. The yeast was added and allowed to stand for 10 min. The weighed acha flour, potato starch, salt, remaining sugar and CMC were premixed for 2 min in a stainless steel bowl mixer. These dry ingredients and the remaining water were added to the yeast mixture and mixed for 5 min using a wooden spoon. The sides of the bowl were scrapped down half way. The resultant batter was proofed in the bowl for 30 min and then transferred to greased aluminum loaf pan and the batter rounded with a spatula. The pan batter was proofed for 45-50 min and baked at 215 C for 5 min, then at 180 C for an additional 40-50 min. The loaves were cooled for 15 min while in the pan, removed from the pan and packaged in polyethylene bag.

Figure 2. Extraction of starch from Irish potato

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Figure 3. Production of AB

Following this method, five different formulations of AB in triplicate were obtained by varying CMC concentration from 1 to 4 g. Also produced for comparison was bread from wheat flour only. The details of the ingredients used in the formulations are shown in Table I. Proximate analysis of acha flour The AOAC (1984) methods were used to determine the moisture, fat, ash and protein content of the acha flour. The carbohydrate content was determined by difference. Loaf volume determination The rapeseed displacement method of NSO (1979) was modified and used to determine the loaf volume of the AB. A wooden box with a wide internal volume was filled with acha grain and the surface leveled with a ruler. The acha in the box was poured into a one litre measuring cylinder and the volume noted (this was the volume of the box). The loaf whose volume was to be determined was weighed and placed in the box. The acha grain from the measuring cylinder was poured over the loaf in the box and leveled. The volume of the spilled acha grain was noted as the volume of the loaf.

Sample codea A B C D E F

Wheat flour (g)

Acha flour (g)

Potato starch (g)

Salt (g)

Sugar (g)

Yeast (g)

Oil (g)

CMCb (g)

Water (g)

– – – – – 100

80 80 80 80 80 –

20 20 20 20 20 –

2.6 2.6 2.6 2.6 2.6 2.6

10.6 10.6 10.6 10.6 10.6 10.6

3.1 3.1 3.1 3.1 3.1 3.1

5.7 5.7 5.7 5.7 5.7 5.7

– 1.0 2.0 3.0 4.0 –

61.5 61.5 61.5 61.5 61.5 58.0

Notes: aSample A, formulation without CMC; B, formulation with 1 g of CMC; C, formulation with 2 g of CMC; D, formulation with 3 g of CMC; E, formulation with 4 g of CMC; F, formulation with wheat flour only; bCMC, carboxymethylcellulose gum

Table I. AB and wheat bread formulations

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The specific volume of the loaf was calculated as the loaf volume per weight of the loaf. Sensory evaluation A 10-member consumer panel was used to access the acha loaves for external appearance, color and general acceptability. The six formulations coded A, B, C, D, E and F were presented to each panelist. The panelists were to indicate their score on a 10 cm structured line scale anchored 1 cm from each end with terms representing extremes of the characteristics. Analysis of variance (ANOVA) was used to establish significant differences among treatment. Duncan’s multiple range test (SPSS, 2001) was used to separate the means where significant differences existed. Results and discussion Proximate composition of acha flour The proximate composition of the acha flour used in this work is outlined in Table II. The values were within the range reported in the literature (Lasekan, 1994; Jideani and Akingbala, 1993). Effect of CMC on AB The effect of cmc on the specific loaf volume is detailed in Table III. Sample A, without CMC had the lowest loaf volume of 316.0  15.6 ml and specific volume of 2.07  0.01 ml/g. There was a significant increase in specific loaf volume with increase in CMC (1-4 g). The addition of CMC gave an increase in loaf volume of 40.0-59.5 per cent.

Parameter

Table II. Proximate composition of acha flour

Moisture Ash Protein Fat Carbohydrate

Samplesc A B C D E F Table III. Effect of CMC on AB qualitya,b

Composition (%) 11.7 1.6 7.7 3.3 75.6

CMC (g)

Loaf weight (g)

Loaf volume (ml)

Loaf volume increase (%)

Specific loaf volume (ml/g)

– 1.0 2.0 3.0 4.0 –

152.9  0.2a 170.7  0.1b 185.3  0.9d 181.2  2.4d 184.8  2.0d 190.0  1.8c

316.0  15.6a 442.5  10.6b 484.0  1.41d 488.0  9.9d 504.0  8.5d 879.5  14.8c

– 40.0 53.2 54.4 59.5 –

2.07  0.01a 2.60  0.01c 2.62  0.01c 2.70  0.02c 2.73  0.07c 4.64  0.12b

Notes: aMean  standard deviation; bAny two means in a column followed by different letters differ significantly (p  0.05); cSample A, bread without CMC; B, bread with 1 g CMC; C, bread with 2 g CMC; dD, bread with 3 g CMC; E, bread with 4 g CMC; F, bread with 100 per cent wheat flour

The specific loaf volume of the acha loaves did not differ significantly ranging from 2.60 to 2.73 ml/g. The loaf made from wheat flour (F) had a specific loaf volume (4.63 ml/g) within the acceptable range for wheat bread. NSO (1979) reported that wheat bread is considered as having a good volume if its volume/weight ratio is not less than 4 ml/g when tested by rapeseed displacement method.

Production of non-wheat bread from acha

Effect of CMC on sensory properties of AB The data on Table IV details the effect of CMC on sensory properties of AB. The mean score for external appearance of the AB ranged from 1.43 to 8.37. There was a significant difference (p < 0.05) in external appearance between the AB samples. The AB without CMC was significantly different (p < 0.05) in external appearance than the others. The loaf with 4 per cent CMC was significantly better in appearance when compared with the other AB. The mean score for crust color of the AB ranged from 1.93 to 8.13. There was a significant difference (p < 0.05) in crust color between the bread samples. The AB without CMC was significantly poor in crust color when compared with the other AB. The AB with 4 per cent CMC was significantly better (p < 0.05) in crust color than others. The mean score for texture of the crumb ranged from 3.32 to 7.08. There was a significant difference (p < 0.05) in crumb texture between the acha bread samples. The AB without CMC was significantly poor in crumb texture when compared to others. The bread with 4 per cent CMC was significantly different in crumb texture than the other acha loaves. However, the loaf from 4 per cent CMC did not differ significantly when compared to the bread made from wheat flour in crumb texture. The mean score for crumb color ranged from 1.76 to 8.27. There was a significant difference (p < 0.05) in crumb color between the AB samples. The AB without CMC was significantly different in crumb color among others. The bread with 4 per cent CMC was significantly different in crumb color among other AB but not significantly different from bread made from wheat flour. The mean score for general acceptability of the AB ranged from 1.66 to 8.17. There was a significant difference (p < 0.05) in general acceptability between the AB samples. The acha bread without CMC was significantly (p < 0.05) poor in general acceptability. The bread with 4 per cent CMC was significantly different from other AB

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Samplesb External appearance Crust color Crumb texture Crumb color General acceptability A B C D E F

1.4a 2.9b 4.9c 4.7c 8.4d 9.5e

1.9a 2.9 4.95b 4.6b 8.1c 9.4d

3.3a 3.3a 4.1a 4.6a, b 7.1c 5.9b, c

1.8a 3.4b 5.2c 5.0c 8.3d 9.4d

1.7a 3.4b 4.7c 4.9c 8.2d 9.4d

Notes: aScores are on a structured scale of 10 cm; bAny two means in a column followed by different letters differ significantly (p  0.05); cSample A, bread without CMC; B, bread with 1 g CMC; C, bread with 2 g CMC; dD, bread with 3 g CMC; E, bread with 4 g CMC; F, bread with 100 per cent wheat flour

Table IV. Effect of CMC on sensory properties of ABa,b

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but not significantly different from bread made from wheat flour in overall acceptability. Conclusion This study demonstrates the possibility of producing AB using CMC gum. The CMC gum was able to retain the gas produced by the yeast during fermentation, thereby maintaining the viscosity and elasticity of the dough. with 4 per cent CMC gave a loaf comparable to wheat bread in terms of crumb color, crumb texture and general acceptability. References Alexander, R.J. (1995), Potato Starch, New Prospect of Old Product, American Association of Cereal Chemists, St Paul, MN. AOAC (1984), Official Method of Analysis of the Association of Official Analytical Chemists, 4th ed., Association of Official Analytical Chemists, Washington, DC. Dziezak, J.D. (1991), ‘‘A focus on gums’’, Food Technology, Vol. 45, pp. 116-32. Encyclopedia Americana (1995), Grolier Inc., Boston, MA, p. 482. Jideani, I.A. (1999), ‘‘Traditional and possible technological uses of Digitaria exilis (acha) and Digitaria iburua (iburu): a review’’, Plant Food for Human Nutrition, Vol. 54, pp. 363-74. Jideani, I.A. and Akingbala, J.O. (1993), ‘‘Some physiochemical properties of acha (Digitaria exilis Stapf) and iburua (Digitaria iburua Stapf) grains’’, Journal of Science Food Agriculture, Vol. 63 No. 2, pp. 369-71. Lasekan, D.O. (1994), ‘‘Chemical composition of acha (Digitaria exilis) flour’’, Journal of Food Science and Agriculture, Vol. 14, pp. 177-9. Lovis, L.J. (2003), ‘‘Alternatives to wheat flour in baked goods’’, Cereal Foods World, Vol. 48 No. 2, pp. 61-3. NSO (1979), ‘‘Nigerian Standard Organisation: standard for white bread’’, NIS, Vol. 75, Federal Ministry of Industries, Lagos, pp. 10-13. Obafunmi, M.O., Yakubu, A. and Balami, Y.A. (2001), ‘‘Nutrition in practical manual on food technology’’, National Science and Technology Forum, Kaduna Polytechnic, Kaduna, Nigeria, p. 27. Okaka, J.C. (1997), Cereals and Legumes: Storage and Processing Technology, Data and Microsystem, Enugu, p. 119. Ranhotra, G.S., Loewe, R.J. and Puyat, L.V. (1975), ‘‘Preparation and evaluation of soy-fortified gluten free breads’’, Journal of Food Science, Vol. 40 No. 1, p. 62. SPSS (2001), Statistical Package for Social Sciences for Windows Release 11.0.0, LEAD Technologies Inc., Haddonfield, NJ. Ylimaki, G., Harrysh, Z.J., Hardin, R.T. and Thomson, A.B.R. (1988), ‘‘Application of response surface methodology to the development of rice flour yeast breads’’, Journal of Food Science, Vol. 53 No. 6, pp. 1800-5. About the authors Victoria A. Jideani was a Senior Lecturer in the Department of Food Science and Technology at the Federal Polytechnic, Bauchi (FPTB), Nigeria and Chairperson, Research Committee, FPTB until November 2006 when she left Nigeria for Botswana. Victoria obtained BSc degree in Food Science, and Technology, MSc in Food Science and PhD in Food Microbiology. She is a professional member of the American Association of Cereal Chemist (AACC), Institute of Food Technologists (IFT), Illinois USA, and the Nigerian Institute of Food Science and Technology

(NIFST). Victoria A. Jideani is the corresponding author and can be contacted at National food Technology Research Centre, Private Bag 008, Kanye, Botswana. Victoria A. Jideani is the corresponding author and can be contacted at: [email protected] Rasheedat Alamu is a Higher National Diploma student at the Department of Food Science and Technology, Federal Polytechnic, Bauchi, Nigeria. Professor Israel A. Jideani was a Lecturer at the Biological Sciences Programme, Abubakar Tafawa Balewa University (ATBU), Bauchi, Nigeria. He is a Fellow of the Nigerian Institute of Food Science and Technology and a Professional member of both the IFT Illinois and AACC. He is now the Director of Research and Development at the National Food Technology Research Centre, Kanye, Botswana.

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