Food Science and Technology Project Topics

Effect of Fermentation on Phytochemical and Mineral Composition of Bread Produced From Wheat, Sweet Potato and Soy Flour

Effect of Fermentation on Phytochemical and Mineral Composition of Bread Produced From Wheat, Sweet Potato, and Soy Flour

Effect of Fermentation on Phytochemical and Mineral Composition of Bread Produced From Wheat, Sweet Potato, and Soy Flour

Chapter One

Objective of the Study

The objectives of the study to determine the effect of fermentation on phytochemical and mineral composition of bread produce from wheat, sweet potato and soy flour.

The specific objectives include the following:

  1. To produce fermented flour from wheat, sweet potato and soy flour
  2. To blend the fermented flours together in different ratios to obtain 5 samples
  3. To produced bread from the flour blends
  4. To determine the phytochemical composition of the bread produced from the flour blends
  5. To determine the mineral composition of the bread produced from the flour blends




Wheat (Triticum spp) is a cereal grain, originally from the Levant region of the near east but now cultivated worldwide. In 2013, world population was 713 million ton, making it the third most-produced cereal after maize (1,016 tons) and rice (745 million tons) (FAO, 2015).

Common wheat (Triticum aestivum L.) is an important component of the human diet and is used in the production of many food products including bread, bread, noodles, steamed bread and cakes, providing energy based on the high contents of protein and carbohydrate. Wheat products contain high levels of antioxidants mostly coming from Phenolies, which confer protection against cancer and heart diseases. Wheat was the second most produced cereal in 2009; world production in that year was 682 million tons, after maize (817 million tons). World trade in wheat is greater than for all other crops combined.

Globally, wheat is the leading source of vegetable protein content than other cereals, maize (corn) or rice. In term of total production used for food, it is currently second to rice as the main human food crops and ahead of maize (Nutrient Data Laboratory United Department of Agriculture). Synthetic antioxidants, such as butylated hydroxyanisole (BHA) and butylated hydroxyl toluene (BHT) are suspected of being carcinogenic and causing liver damage. It is believed that an increased intake of food, which is rich in natural anti-oxidants, is associated with a lower risk of degenerative diseases, particularly cardiovascular diseases and cancer.

 Origin and Distribution of Wheat

Cultivation and repeated harvesting and sowing of grains of wild grasses led to the creation of domestic strains, as mutant forms (sports) of wheat were referentially chosen by farmers. At the beginning of recorded history, wheat was already an established crop whose origin was unknown. There is however some evidence that cultivate of wheat started about 6000 years ago in the Syria-Palestine area and spread to Egypt, India, Russia, Turkey and Central Europe from where it spread to other countries and continents. According to (Olugbemi, 2008), countries that produce wheat today include Russia, Switzer land, the United States of America, Belgium, Canada, Norway, Sweden, South Africa, Peru, Australia, Chile, New Zealand and Nigeria. There are different types of wheat, these include the hard red spring, hard red winter, durum, soft red and spring/winter wheat. Others include Manitoba and English soft wheat (Nnenne, 2008).

Wheat grains are ovoid in shape. The wheat is a seed, which is fitted for reproducing the plant from which it came. The germ is an embryo plant, with a radical, which can grow into a root system and a plumule, which can develop into stems, leaves and ears.

Composition of Wheat Grain

Like any seed, the wheat kernel is a complex structure with many individual components, however with respect into three general anatomical regions. The outer protective layers of the kernel are collectively called the brain. The brain comprises about 14% of the kernel by weight, and is high in fiber and ash (mineral) content.

The germ, the embryonic wheat plant, comprises only about 3% of the kernel. Most of the lipids and many of the essential nutrients in the kernel are concentrated in the starchy or storage endosperm, which provides the energy and protein for the developing wheat plant. It is characterized by its high starch and moderately high protein (i.e gluten) content.

The endosperm constitutes the major portion of all kernels and is the primary constituent of flour. Finally a single, highly specialized layer of endosperm cells form a border between the starchy endosperm and the bran. This layer, called the aleurone, is usually considered part of the endosperm but it is biologically much more active and subsequently, contains high enzyme activity.

Because of its composition activity and location, it can exert a variety of negative effects on the acceptability of flour. Consequently, it is generally removed as part of the bran during most flour milling operations; in fact millers consider the aleurone to be part of the bran (Kent, 2003).

Nutritional Value of Wheat

Flour contains form 65 to 70 percent starch, but it is most important nutrient value lies in its 9 to 14 percent protein content. Giladin and gluten are the principal proteins, constituting approximately 80 percent of the glutton (Maud, 2000), cellulose, fats and sugar total less than 4 %.

Endosperm: the inner part of the wheat kernel (about 83% of the kernel), consists mostly of starch and 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 ribofloavin 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 unobservable 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.

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




 Collection of Materials

            Wheat, sweet potato and soybean were all purchased from the main market (Oja-oba) in Owo, Ondo State. The raw materials (wheat, sweet potato and soybean) were all processed into flour in the processing laboratory of Food Science and Technology, Rufus Giwa Polytechnic, Owo, Ondo State.


Preparation of wheat flour

Wheat flour was produced as described by Adegunwa et al., (2015) (fig 3.1). The Wheat grains were sorted and cleaned to remove stones, dirt, and infested grains. The cleaned Wheat was then dry milled then sieved, the sieved wheat was then allowed to pass through a 250-micrometer mesh.




Table 4.1: Phytochemical composition of bread produced from fermented flour blends





The results of this study revealed the phytochemical and mineral composition of bread produced from fermented and unfermented flour blends from wheat, sweet potato and soybean flour blends. The phytochemical properties of bread from both unfermented and fermented flour blends was recorded to have almost the same phytochemical compositions, fermentation might reduce the phytochemical properties of the bread samples, although unfermented bread samples was observed higher in glycosides compared to fermented bread samples. The mineral composition of unfermented and fermented bread samples was observed to have little difference, both flour samples have appropriate amount of mineral composition that is beneficial to humans. From the result it can be concluded that both fermented and unfermented bread samples have no significant difference in their phytochemical and mineral composition.


            Based on the findings in this study, it is therefore recommended that food industries should look more into production of bread from fermented flours, since it helps reduce the anti-nutrient content of the raw materials which can be harmful to human health.


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