PRODUCTION AND PROXIMATE EVALUATION OF BREAD FROM BLENDS OF WHEAT, PRO-VITAMIN A CASSAVAAND DATE FLOUR

INTRODUCTION 1.1 Background of study Bread is a bakery product priced for its taste, aroma and texture. It is a staple food prepared by baking dough of flour and water (Osuji, 2006), the consumption of which is steady and increasing in Nigeria (Edema et al., 2005). Wheat flour is generally the main ingredient for bread and baked product in Nigeria in particular and in the world generally. In many developing countries bread consumption is continually expanding and there is increasing dependence on imported wheat. Most of these countries however grow staples other than wheat that can be used for bread. In Nigeria, wheat production is limited and wheat flour imported to meet the local flour needs for bakery products which result in huge burden on the external reserves of our nation (Giami et al., 2004). According to Olaye et al., (2006), Eke-Ejiofor and Owuno(2012), efforts have been made to promote the use of composite flour in which flour from locally grown crops and high protein seeds replace a portion of wheat flour for use in bread, thereby decreasing the demand for imported wheat and producing protein enriched bread. The production of composite flour using various crops for confectionary are been carried out by many researchers, among which are; cassava/wheat flour (Shittu et al.,2013), wheat/taro flour(Ammar et al.,2009),wheat/pumpkin flour (Shittu et al.,2008) and tiger nut/wheat flour (Ade-omowaye et al.,2008), and according to Khan(2005) composite flour technology has many advantages among which are; it plays a vital role to complement the deficiency of essential nutrients; it promotes high yielding local plant species and enhances overall use of domestic agriculture. Cassava root is good source of starches (about 80%) but is limited in proteins, fats and minerals (Montagnac et al., 2009). Pro vitamin A cassava has been enriched with vitamin A which is an essential nutrient lacking in the diets of poor, malnourished population, pro vitamin A cassava (bio-fortification) could significantly improve nutrition and overall health, specifically among poor communities (Effiong et al .,2015).Date is rich in high quality carbohydrate (63% sugar and 8% dietary fiber), the primary carbohydrates are monosaccharide, comprising glucose (23-30%), fructose (19-28%) and non-starch polysaccharides (7-10%) of the fruits weight (Al-mssallem,2020). The sucrose content is negligible (Yasawy, 2016). Wheat flour for bread has starches and functional protein glutens that favour the processing of leavened aerated bread, but is limited in fat and balanced amino acid (Goesaert et al., 2005). According to technical center for agricultural and rural co-operation (2007), and Yimer (2008), in Ethiopia and other eastern African countries, cassava and dates are underutilized. Therefore, there is need to increase the utilization of cassava and dates as composite flours in the development of different food products such as bread. Such effort will migrate foreign exchange a bill spent on importing wheat grains, help to stabilize seasonal fluctuations in the wheat grains supply and provides employment opportunity for local processors. Thus, partial substitution of wheat flours with date and cassava (pro-vitamin A cassava) flours has high potential to enhance the nutrient and bio-active content of bread, and provides economic benefit for countries in short of bread wheat supply. A lot of studies on bread formulation has been commissioned in different countries, to achieve wheat flour substitution, resulting in varying degrees of success (Begun et al .,2011; Dhingra and Jood,2004; Jensen et al.,2015; Nwanekezi,2013; Shao et al.,2009; Shogren et al.,2003). Bread in which wheat flour replacement is allowed with cassava flour, about 30% (Jensen et al.,2015) and 20% (Begun et al.,2011) level of substitution of wheat flour have been reported in previous studies to produce acceptable bread with insignificant variation, when compared to bread made with 100% wheat flour. Cassava flour is virtually starch, and is limited in amylase enzyme activity, which negatively affects the texture of the bread, by diluting wheat gluten functionality, even though it can impart whit and blend taste to the bread. Although, pro-vitamin A cassava can increase the nutrient composition of the bread where by providing an essential role of nutrients in the diets of households (Oparinde et al.,2016; Garg et al.,2015; Onyeneke et al.,2020). Addition of date can increase the daily value with potassium (22%DV) and a moderate source of pantothenic acid, vitamin B6 and the dietary minerals magnesium and manganese (10-19%DV), with other micronutrients in low amount. Information on appropriate blending ratio for pro-vitamin A cassava and date composite flours to produce bread of acceptable quality to consumers is limited. Therefore the work is designed towards the evaluation of quality characteristics of bread from composite flour. 1.2 Statement of problem The rate of demand of wheat flour is very high, resulting in huge burden on the external reserves of Nigeria due to the high rate of importation of wheat flour. Vitamin A deficiency such as vision impairments has prevailed in Nigeria and this has imposed threats to children and pregnant women of poor households in Nigeria. 1.3 Aim and objective This study is aimed at the production and proximate evaluation of bread from blends of wheat, pro-vitamin A cassava and date composite flour 1.4 Specific objective of this work are too; • Produce flour from pro-vitamin A cassava and date fruit • Produce bread from the composite blend of flours • Evaluate the proximate composition of the bread samples • Evaluate the sensory properties of the bread samples, to ascertain the best blend 1.5 Justification of the study • To reduce the importation of wheat flour by substituting it with other nutrient dense materials (composite flours, such as pro-vitamin A cassava/date) in the production of baked products and other confectionaries. • To reduce vitamin A deficiencies such as vision impairments from poor households in Nigeria by producing nutrient dense baked products using pro-vitamin A cassava and date composite flour.