CHAPTER ONE

1.0     INTRODUCTION

Bread is a staple food prepared from a dough of flour and water usually by baking. It is a good source of good nutrient such as macronutrients (carbohydrates protein, and fats) and micronutrients (minerals and vitamins) that are essential for human health.

Its origin dates back to the Neolithic era and is still one of the consumed and acceptable staple food products in all parts of the world.

The word bread is used to describe the whole range of different varieties of bread which may vary in weight, shape, crust hardness, c  \rumb cell structure, softness, colour and eating quantity.

There are many combination and proportion of types of flour and other ingredients and also different traditional recipe and modes of preparation of bread. Bread may leavened by different processes ranging from the use of naturally occurring microbes (sourdough recipe) to high pressure artificial aeration method during preparation or baking. However, some products are left unleavened either for preference or for traditional or religions reasons.

In Nigeria, bread has become the second most widely consumed non-indigenous food products after since. It is consumed extensively in most homes, restaurants and hotels. It has been hitherto produced from wheat as a major raw material. In Nigeria, wheat production is limited and wheat flour is imported to meet the local flour needs for baking products. Thus, huge amount of foreign exchange is used every year for the importation of wheat. Effort has been made to promote the use of composite flour in which flour from locally grown gaps replace  a portion of wheat flour for use in bread, thereby decreasing the demand for imported wheat and helping in producing bread.

Composite flour is a mixture of wheat with other materials replacing substantially a portion of wheat flour to form suitable flour for baking purposes. The idea of composite flour began by food and Agricultural organization (FAO) in 1960s to reduce the important dependency of developing countries. (Onyeku et al; 2008, Sibel  2006; Owuamanam, 2007). There is now a substantial quantity of composite bread in the market, such bread requires at least 70% wheat flour to be able to rise because wheat contains gluten.

Wheat in conventional flour, rich in gluten, which makes a better preference for bread baking. It is however expensive because it is not grown in Nigeria due to the unfavourable climatic condition using huge foreign exchange (Igbabu Biana Dooshima, 2014).

The unbridled importation of food by developing countries is detrimental to their local economy and threatens food security. Many developing countries spend large proportion of their foreign exchange earnings on food especially wheat. It is therefore, of economic importance if wheat importation is reduced by the substitution with other locally available raw materials (Onyeku et al; 2008) such as cassava, maize, potato and other carbohydrate flour.

High quantity cassava flour has been identified as a local alternative to substitute part of wheat flour in composite flour in Nigeria due to high production of cassava in Nigeria. In Nigeria, cassava is one of the most important crops in terms of production energy intake and contribution to Agricultural GDP. The possibility of using starchy tubers as part of bread production instead of 100% wheat flour depends on their chemical and physical properties. Those in bakery sector have given reasons for the slow adoption of this technology, including ease of deterioration of cassava bread due to high moisture content and microbial load, fear of the presence of toxic components in cassava and finally bulkiness.

Of interest in this project work is the production of bread using wheat and cassava flour blends flavoured with ginger.

Ginger, an antioxidant have been chosen in this work to be used an a flavouraing agent. Ginger does not only serve an a flavouring agent but also has health benefit.

The new study published in LWT-food science and technology suggests that enriching bread with ginger could boost its antioxidant content without having adverse effect on any functional or sensory properties due to potential health benefits, ginger has gained considerable attention as a botanical dietary supplement in both U.S and Europe in recent years, especially for the use in treatment of chronic inflammatory conditions. Gingerols  are group of phenols found  in ginger that are suggested to offer health benefit (Nathan Gray, 2010).

1.2 OBJECTIVE OF THE STUDY

-     To produce bread using composite flours of wheat and cassava flavored with finger of varying ratios.

It is hoped that the result will increase the utilization of cassava flour and will reduce the pressure on wheat flour for the production of bread and other bakery products that are of good and acceptable quality.

1.3 BREAD

       Bread is an age long product and a staple food prepared principally by baking dough of flour. Bread is a food product that is universally accepted as a very convenient of form food that has desirability to all population both the rich and poor, rural and urban.

1.3.1 Nutritional value of bread

       Bread supplies a significant portion of the nutrients required for growth, maintenance of health and well-being. It is an excellent source of proteins, vitamins, minerals, fiber and complex carbohydrate. It is also low in fat and cholesterol. Bread is quite bulky,  so it takes longer to digest and therefore more satisfying and less fattening than fats, sugars and alcohols commonly consumed in excess. All bread are nutrition’s and the difference between them in nutritional value are not significant if we eat a balance diet.  

 1.4 WHEAT AND ITS NUTRITIONAL INFORMATION 

       Wheat flour contains from 65-70% starch, but it’s most important value lies in its 9 -14% protein content. Gliadin and gluten are the principal proteins, constituting approximately 8% of the gluten. Cellulose, fats and sugar total less that 4%.

Endosperm:  The inner part of the wheat kernel (about 83% of the kernel) consists mostly of starch and it is the source of white flour. Of the nutrients in the whole kernel, the endosperm only contains about 43% of the pantothenic acid, 32% of the riboflavin, 12% of the niacin, 6% of the pyridoxine, 3% of the thiamine and 70-75% of the protein.

Bran: Of the nutrients in the whole kernel the bran (in addition to vital unabsorbable fiber or roughage) contains about 86% of the niacin, 73% of the pyridoxine,  50% of the pantothenic acid, 42% of the riboflavin, 33% of the thiamine and 19% of the protein.

Germs: Of the nutrients in the whole kernel, the germ contains about 64% of the thiamine, 26% of riboflavin, 21% of the pyridoxine, 7% of the pantothenic acid, 2% of the niacin and 8% of protein.

1.4.1 Health benefits associated with wheat

In the words of Beuchat, L.R. (1999) wheat bring with itself loads of health benefits that can be discussed as follows

-     Bread, which is made of wheat flour, is extremely nourishing which gives strength and vitality to people with high appetite. It also helps in curing nose bleeding when wheat is dissolved in milk and sugar is consumed by the victim.

-     It is a rich source of vitamin B and basic amino acids including argentine and lysine.

-     Wheat also helps in curing constipation and also beneficial for people suffering from cancer.

-     The whole grain in wheat helps in preventing diabetes as it influences the insulin level through maintaining the body weight.

 1.5 NUTRITIONAL VALUE OF CASSAVA FLOUR

Cassava is good and cheap source of carbohydrate. After sugarcane, is considered the highest producer of carbohydrate.

1.5.1 Health Benefits of Cassava

-     Cassava has nearly twice the calories than potatoes, highest for any tropical starch rich tubers and roots. 100g root provides 160 calories. Their calories mainly comes from sucrose forming the bulk of  the sugars in tubers, accounting for more than 69% not the total sugars.

-     Cassava is a moderate source of some the valuable B- complex group of vitamins such as folate, thiamin, pyridoxine (vitamin B-6), riboflavin and pantothenic acid.

-     The root is the chief source of some important  minerals like zinc, magnesium, copper, iron and manganese for many inhabitants in the tropical belts.

As in other roots and tubers cassava too is free from gluten. Gluten free starch is used in special food preparations for celiac disease patients.

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