CRUST AND CRUMB CHARACTERISTICS OF GLUTEN-FREE BREAD PREPARED FROM AFRICAN BREADFRUIT, CASSAVA AND MAIZE FLOURS
ABSTRACT
Analysis was conducted to study the crust and crumb characteristics of gluten free breads prepared from African bread fruit, cassava and maize flours. Much of the differences were found on the physiological and sensory characteristics. It was observed that while there were multiple fissures (cracks) on the crust of bread made from African bread fruit, maize and cassava, there was none on wheat bread crust. The length of major fissures on crust was another distinguishing feature. Maize crust had 9.00cm, cassava had 8.50cm while African breadfruit had 8.20cm and wheat had no cracks. The difference in colour was another important attribute, wheat bread crust had 50.50% brownness while that of maize was 40.00%, cassava bread crust had 93.00% while 88.00% was observed in African bread fruit crust. Crumb colour of wheat bread was 70.10%, maize bread crumb was 20.00% cassava bread crumb was 80.00%, sensory parameters also revealed the similarities or difference in the crust and crumb of the four samples. Crust appearance of bread from maize was 5.53± 0.27 while that of wheat bread was 7.96± 0.19, cassava bread crust scored 4.66± 0.38 and bread from African breadfruit crust was 2.23± 0.18. Crumb appearance for wheat bread scored 7.80±0.21 while maize and cassava bread crumb scored 5.66±0.31 and 4.20±0.26 respectively. There were significant difference in crust and crumb characteristics for appearances and taste, however, there was no significant differences on crust taste between maize and cassava samples. Significant differences were determined at 5% probability level (P = 0.05).
KEY WORDS: GLUTEN-FREE BREAD, AFRICAN BREAD-FRUIT, CASSAVA, CRUST COLOUR, CRUMB COLOUR.
TABLE OF CONTENTS
Dedication - - - - - - - - - i
Certification - - - - - - - - - ii
Declaration - - - - - - - - - iii
Acknowledgement - - - - - - - - iv
Abstract - - - - - - - - - - v
Table of Contents - - - - - - - - vi
List of Tables - - - - - - - - ix
List of figures - - - - - - - - - x
List of plates - - - - - - - - - xi
CHAPTER ONE
1.1 Introduction - - - - - - - - - 1
1.2 Statement of the Problem - - - - - - 3
1.3 Aim/Objectives - - - - - - - - 3
CHAPTER ONE: LITERATURE REVIEW
2.1 Bakery Products as the Basis of Traditional Diet - - - 4
2.2 Gluten-free Bakery Products - - - - - - 5
2.3 Gluten Free Flours - - - - - - - - 6
2.4 Raw Materials for Gluten Replacement - - - - 7
2.5 Quality of Gluten Free Bread - - - - - - 7
2.6 Nutritional Value of Gluten Free Bread - - - - 8
2.6.1 Protein - - - - - - - - - 9
2.6.2 Carbohydrates - - - - - - - - 10
2.6.3 Lipids - - - - - - - - - 11
2.6.4 Minerals - - - - - - - - - 12
2.5 Gluten Free Bread Availability and Storage - - - 12
CHAPTER THREE: MATERIALS AND METHODS
3.1 Source of Raw Materials - - - - - - - 14
3.2 Preparation of African Breadfruit Flour - - - - 14
3.3 Preparation of Cassava Flour - - - - - - 17
3.4 Production of Gluten Free Bread - - - - - 19
3.5 Quality Parameters - - - - - - - 22
3.6 Crust and Crumb Colour Analysis - - - - - 22
3.6.1 Determination of Bread Colour - - - - - 22
3.7 Determination of Proximate Composition - - - - 23
3.7.1 Determination of Moisture Content (A. O. A. C., 2005) - - 23
3.7.2 Determination of ash content (A. O. A. C., 2005) - - 24
3.8 Determination of Crude Protein (A. O. A. C., 2005) - - 25
3.8.1 Determination of Crude Fat (A. O. A. C., 2005) - - - 26
3.8.2 Determination of Crude Fibre Content (A. O. A. C., 2005) - 27
3.8.3 Determination of Carbohydrate (A. O. A. C., 2005) - - 29
3.8.4 Determination of Energy Value - - - - - 29
3.8.5 Sensory Evaluation - - - - - - - 29
3.9 Statistical Analysis - - - - - - - - 30
CHAPTER FOUR: RESULTS AND DISCUSSION
4.1 Result and Discussion - - - - - - - 35
4.2 Physiological Qualities - - - - - - - 37
CHAPTER FIVE
5.1 CONCLUSION - - - - - - - - 44
5.2 RECOMMENDATION - - - - - - - 45
REFERENCES - - - - - - - - - 46
APPENDIX - - - - - - - - 49
CHAPTER ONE
1.1INTRODUCTION
Bread is an important staple food made from grains such as wheat. Wheat contain gluten which contributes to the elasticity of dough and is thus an important component of bread, but celiac disease is activated by proteins in cereals, which are usually classified as prolamins, as they are soluble in 70-90% alcohol. Wheat prolamins, called gliadins, together with another storage protein glutelin, could forma complex called gluten(Dorota et al.,2014).
However, many individuals are so sensitive to gluten’s gliadin fraction that they cannot tolerate even very small amounts of gliadin. The World Health Organization states that gluten-free food should contain less than 1mg gliadin per 100g product. African breadfruit flour, cassava flour and maize flour can alternatively be used in bread making. Gluten free products contain low levels of sodium and a high amount of easily digested carbohydrates, making it desirable in celiac diets. But they cause technological difficulties in bread making and impart unusual taste to bread. Gums, replacing gluten in bread formulations also offer substantial technological improvements(Christiansun et al.,1974).
In general, gluten free bread mixtures do not have the same texture as wheat flour dough. These mixtures cannot hold the carbon dioxide gas produced by yeast. Bicarbonate of soda and tartaric acid still need to be added to the mixture to help it rise. Gluten free breads will seem drier, harder and have a darker texture than wheat bread yet; they have excellent nutritional value and can offer a variety of flavours(Alvarenga et al., 2011).
To produce gluten-free bread the replacement of that chemical entity is based on the research of other flours such as maize, rice, potato starch, soybeans flour, African bread fruit flour, cassava and tapioca.
Nevertheless, the supplement of dough without gluten additives is difficult, because its structure is weaker than the normal dough of wheat and, additionally, supplements can easily destroy it. Some studies suggest that the easiest way to use a supplement in bread dough to ensure that the viscoelastic properties are maintained is the use of hydrocollids.
1.2 STATEMENT OF THE PROBLEM
In bakery products gluten provides a network, which is responsible for water binding and viscolastic properties of the dough, allows gas retention and supports final porous structure of the crumb. It is now very important to investigate the crumb and crust characteristics of gluten-free bread.
Celiac disease is activated by the consumption of some storage proteins present in cereals and could form a complex called gluten. Therefore, there is need to produce a gluten-free bread.
1.3AIM/OBJECTIVES
⦁ This work aims to evaluate the crumb and crust characteristics of gluten-free bread similar to wheat composite flour.
⦁ Determination of sensory parameters so as to ascertain their level of acceptability.
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