MICROBIAL ANALYSIS OF TOAST BREAD

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ABSTRACT

The analysis of toasted bread was carried out to determine the microbial load. A total of two sample were collected from Douglas market. The analysis was performed in the microbiology laboratory, Imo State University. From the analysis, the microbial count of the Total Heterophilic bacteria count ranges from 1.2-2.8 X106, Total coliform count ranges from 7.8-9.8 X106, TSC ranges from 1.9-2.3 X106, and Total fungi count ranges from 1.6-1.7 X106. Further identification scheme carried out on microbial isolates showed the presence of five bacteria which are Escherichia coli., Salmonella spp., Bacillus spp., Staphylococcus spp., and Klebisella spp. and three fungi which are Rhizopus spp., Mucor spp., and Aspergillus spp. Toast bread which is a good source of nutrients, however microbial loads above 105 tolerant limits and the presence of coliform calls for concern, adequate hazard analysis and critical control point (HACCP) measures the effective good manufacturing practice (GMP) is imperative in the production of bread.

 

 

 

 

 

 

CHAPTER ONE

1.0  INTRODUCTION/LITERATURE REVIEW

1.1 INTRODUCTION

Bread may be described as a fermented confectionary product produced mainly from  wheat flour, water, yeast and salt by a series of process involving mixing, kneading, proofing, shaping and baking (Dewettinck et al., 2008). The consumption of bread and other baked goods such as biscuits, doughnuts and cakes produced from wheat flour is very popular, but the low protein content of wheat flour, which is the most vital ingredient used for the production of different kinds of baked goods has been major concern in its utilization (Young, 2001).

However, wheat is a good source of calories and other nutrients but its protein is of lower nutritional quality when compared to milk, soya bean, pea and lupin proteins as its protein is deficient in essential amino acids such as lysine and threonine (Bakke and Vickers, 2007; Dewettinck et al.,008; Jideani and Onwubali, 2009). The use of white flour derived from the processing of whole wheat grain, which is aimed at improving the aesthetic value of white bread, has also led to the

drastic reduction in the nutritional density and fibre content when compared to bread made from whole grain cereals (Maneju et al., 2011).Recently, consumers’ awareness of the need to eat high quality and healthy foods – known as functional foods, that is,foods which contain ingredients that provide additional health benefits beyond the basic nutritional requirements, is increasing (Ndife and Abbo, 2009). Therefore, the trend is to produce specialty breads 10 Baba, et al.: Sensory Evaluation of Toasted Bread Fortified with Banana Flour: A Preliminary Study made from whole grain flour and other functional ingredients

known as health breads or functional foods (Dewettinck et al., 2008).

The banana fruit is a healthy, nutritious commodity which contains 74%, 23% carbohydrates, 1% protein and 0.5% fat. Without its peel, it is a good source of Vitamin B6, potassium and fiber. Moreover, it has no sodium and cholesterol and is a great source of Vitamin C and magnesium and contains three natural sugars – sucrose, fructose and glucose giving an instant, sustained and substantial boost of energy (http://www.ffc.agnet.org/library). Potentially, it can be processed and preserved to expand its market value such as, pure from ripe fruits for use in ice cream, yogurt, cake, baby foods and nectar; sliced and canned in syrup for use in fruit salads and as toppings; sun dried banana crispy; and, fermented to produce vinegar and alcoholic beverage. A new product with commercial value is the banana flour which can be used as a mixture for various cakes and breads. But since it does not contain gluten, it could not be used as the main ingredient but rather mixed with wheat flour in the production of quality baked products.

Most Nigerian’s are consuming bread as a traditional food item. Wheat flour is the major component of bread. Since wheat is not a tropical crop, it is imported at high cost to meet the rising trend in demand (Udofia et al.,2013). Efforts of government to embark on local production of wheat have been failing; the situation is not likely to improve on account of unfavorable agronomic conditions of the crop in Nigeria. The presence of gluten and glutenin confers wheat with unique baking properties. Wheat may contain some anti–nutritional factors like phytate and tannins especially if not properly processed (Zharfi et al., 2012).

Bread as a daily food is of high interest, therefore its production and distribution deserves improvement. Based on available data, food fibers are considered useful substances for human consumption (Ndife et al.,2011); therefore nutritional expert try to find appropriate methods of adding fiber to food preparations, especially bread. For instance, in Ghana bakery products are prepared with food fibers, and breads enriched with soluble fibers are very valuable. Banana is a high fiber fruit and its consumption decrease blood cholesterol. Addition of about 300 – 500g/kg freeze dried banana to diet had a reducing effect on cholesterol (www.dietaryfiber.food.com/fiber-rda.php.). In general, the more soluble fiber and protein in a bread formulation, the tendered and more nutritious the bread will be. Mohammed and Jingyuan (2010) opined that plantain flour is rich in some vitamins, minerals, antioxidants, proteins and fibers which can decrease heart disease, blood cholesterol, cancer, diabetes and renal calculus. Fortification of bread with banana flour has been reported to improve other useful properties in bread. This was confirmed by Chong and Noor-Aziah (2008) who reported that addition of fiber such as banana powder (10%) to bread formation enhanced water absorption and lengthened dough mixing time. Zhu et al., (2005) reported that banana starch had high resistance to enzyme activity as well as high viscosity. Aparicio–saquilan et al., (2007) produced cookies containing 15% banana powder and found that these cookies had more digestibility and shelf life than control cookies.

Good bread can be made from dough to which adequate amount of yeast is added. The dough is allowed to ferment and kept at desirable temperature for an appropriate period of time. Unfortunately, in most bakeries recovery defects due to under – fermented dough as well as poor flour quality, leaves no choice than to use chemicals such as soda, blanket (sodium hydrosulfite), extra salt for the reduction of gluten fluidity and increase dough elasticity. This practice has health implications such as and is a cause of stomach trouble, malnutrition, increased blood pressure and allergies (www.dietaryfiber.food.com/fiber-rda.php.). This generally affects sensory qualities and overall acceptability of bread (Eddy  et al., 2007). The major or mandatory ingredients in bread making are flour, water and yeast (Akobudu, 2006; Osuji, 2006). The flour should have good amylase activity, the moisture content should be less than 14% and the colour or appearance should be satisfactory (Giami et al., 2004). Due to the high cost, geographical scarcity and high demand of wheat flour, efforts are being directed towards the provision of alternative source of flour. For example, Eduardo et al. (2013) reported that composite bread can be made by substituting 5, 10, 15, 20 and 30% plantain flour for wheat flour. Sensory evaluation evokes measures, analysis and interpretation of consumers’ responses to products as perceived by senses of sight, smell, touch, taste and hearing. The consumer buys nutrition, convenience, image and functionality in food. Therefore, new products must provide all the responses like or near the older product (Udofia et al.,2013).

1.2 AIM AND OBJECTIVE

Aim

The aim of this study is to isolate and indentify microorganisms find in toast bread

Objective

  • To determine the microbial load of the toast bread