Using fruit to preserve bread
The materials required for this science project:
- A loaf of plain bread
- A loaf of raisin paste-filled bread
- A loaf of prune paste-filled bread
- A loaf of dates paste-filled bread
- A magnifying glass
- A pair of plastic gloves
- A bottle of disinfected water
- A soap
- A clean towel
1. For this experiment, the independent variable is the type of bread used – plain, prune paste-filled, raisin paste-filled and date paste-filled. The dependent variable is the number of days it takes for mold to appear on the surface of the bread. This is determined by inspecting the bread with a magnifying glass. The constants (control variables) are the size of the bread, the hygiene level of the bakery and the type of packaging used for the bread.
2. Plain bread, prune filled bread, raisin filled bread and date filled bread loaves are bought from a local bakery. They must be freshly baked in the bakery on the same day. This is to ensure that the source of water, other raw materials and the oven used to make the bread are the same. The packing and handling method should also be the same for all 4 loaves of bread.
3. The 4 loaves of bread are then left in a cupboard. Before handling the bread, wash your hands with soap and disinfected water. Wear plastic gloves after drying your hands with a towel.
4. The 4 loaves of bread are inspected everyday with a magnifying glass for signs of bacteria or mold growth. Do not remove the bread from the packaging. The observations are recorded in the table given below.