The bar chart shows the height of the doughnuts before and after baking. The rising of the dough during baking is caused by the fermented yeast during proving that has produced carbon dioxide in the dough. During baking, the dough rises rapidly as the gases inside the dough expand. But at 54 degrees Celsius, further rising stops as the yeast is killed. Differences in height depend on the type of flour used.

The above star diagram shows the characteristics of the doughnuts, with 1 being the least appealing and 5 the most appealing. The first characteristic, colour, Variation C, at 5, has the best colour given its golden brown look. Variation B has the least appealing colour, at 2, as it was very dark brown in colour and looked burnt, though it was not. Variation A and the control had averagely appealing colours with Variation A being just brown in colour and the control, very light brown. Both are just as appealing. The 2nd characteristic, texture, the control, was rated 5 with its smooth surface. Variation A has the least appealing texture, at 1, as it felt coarse, rough and grainy. Variation C was appealing, though as not as much as the control. It was smooth, with a few humps. Variation B was not very appealing, though better than Variation A with its coarse and rough texture. The 3rd characteristic, taste, the control and Variation C has the best taste, at 5 as they were both equally soft and chewy. Variation A was very hard and difficult to chew, thus it was only rated 1. Variation B was soft but not chewy. The last characteristic, moisture, the control has the best moisture, at 5, as it was soft and bouncy to the touch. Variation C is 2nd with its slightly soft and bouncy feel. Variation A and Variation B was rated 2 because they were hard and dry as they lacked moisture.

Conclusion

The experiment that I have carried out have proved that different types of flour(plain, wholemeal, brown a.k.a wheatmeal, strong) will result in different characteristics, in terms of colour, texture, taste, moisture and height, upon baking. Flours are complex carbohydrates as they contain starch. Flour is the fine powdery substance that when mixed with water, forms gluten, which is a complex protein. Gluten gives dough an elastic structure and allows the retention of gas bubbles in an intact structure which results in a sponge-like product called dough. The higher the protein content of the flour, the more gluten will be formed when it is mixed with water. Fat such as butter or oil is added to the mixture to lubricate and shorten the gluten strands. The different types of dough will result in different characteristics upon baking, depending on the types of flour used.

When water is added to flour, water molecules combine with 2 proteins, gliadin and glutenin to form gluten. At first, the protein molecules that are formed are tangled and chaotic but as the dough are mixed, they line up with one another, forming gluten strands. During kneading, the protein molecules become more closely aligned and the gluten becomes stronger and more elastic. The dough is now able to hold gases produced by yeast, which causes the bread to rise. In this experiment, the control and Variation B has raised the most, as compared to the other variations. This is because plain flour is usually used where a shorter and finer texture is required, allowing more carbon dioxide to be formed in the dough given its light flour properties, as it contains only the endosperm of the grain, and brown flour contains the endosperm and germ but only the inner layers of the bran, with very course bran particles that are removed during milling and this gives a better rising during baking. However, Variation A, wholemeal flour, contains all the bran and germ with nothing added or removed. It is heavy and close-textured, because the bran and germ reduce the rise. As for Variation C, strong flour did not rise as much as the control or Variation B because it is heavier in density and its high-protein content and high water absorbency properties limits its rise.

The properties of gluten vary with its composition, which differs according to its source. Thus, doughs range from soft and extensible to tough and elastic, depending on the gluten in flours. Different types of flours have different absorbency levels. Variation A was the coarsest, dry and rough in texture and very hard and dry as it lacked moisture. This is because wholemeal flour absorbs more water than plain flour in order to get the right shape and texture for the bread. In this experiment, all the variables were fixed except for the types of flour used, so this lead to the different amounts of moisture in the different breads. The amount of moisture determines the texture and taste of the bread. The control and Variation C was soft and chewy while Variation B was soft and not so chewy, as they were both moist and not heavy in density. Variation A was dense and heavy, that lead its taste to be very hard and difficult to chew because it lacked moisture. The control and Variation C too had the best texture, as they were both smooth and bouncy to the touch. Variation A, again, had a coarse, rough and grainy texture as it was dry. Variation B on the other hand, did not contain as much moisture as the control or Variation C but it was moister than Variation A therefore, its texture was not smooth, but just coarse and rough.

The difference in colour among the control and variations is caused by the amount of starch that is present in the flour. The more starch content there is in the flour, the more starch will be dextrinized, causing it to be brown in colour. Browning of the bread occurs not only from the dextrinization of the starch, but also the caramelization of sugar, as well as the maillard reaction. In this experiment, Variation C had the best golden brown colour as strong flour contains the right amount of starch that is needed to give bread the right brown colour to the crust. However, Variation B had the least appealing colour as it was very dark brown and looked over baked, though it was not. Though brown flour does contain a reasonable amount of starch, the endosperm, germ and inner layers of the bran has contributed to the cause of the further darkening of the bread upon baking.

In conclusion, different types of flour have their own properties that will result in different characteristics depending on how they are prepared and cooked. Plain flour and strong flour is therefore recommended to be used if a nice texture, colour, and mouth feel or taste is desired.