In this text-based activity, students look at the preparation of a buffet lunch for a school fete. They are asked to highlight areas of poor hygiene that could cause problems such as food poisoning.
Food safety
Finding the additives
Students are given the ingredients list from a vinaigrette salad dressing, and have to identify the different additives it contains.
Reading the label
By law, food manufacturers must list, on the packet, the ingredients in their products. Ingredients are usually listed in descending order by weight.
Students are given the ingredients list for a cheese and ham pasty, and will then answer questions on its contents.
What can be added to the food you buy?
Students will learn about the main classes of food additives, and their purpose
Guess the food from the labels
Students are given copies of ingredients labels from several common foods, including baked beans, cornflakes, ice cream and naan bread. They are challenged to identify the food from its ingredients.
Would you eat these for breakfast?
The purpose of this activity is to illustrate that all foods are chemicals.
Students are given lists of ingredients from five breakfast foods. They are asked to identify them and consider how palatable or otherwise they appear from their chemical constituents.
Investigating the action of an anti-caking agent
The problem with powders is that the particles tend to clump together. This makes processing difficult and leads to inconsistencies in the texture of foods.
In this lesson, students can design and carry out an investigation to see the effects of an anti-caking agent on the flow of cocoa powder.
Function of anti-caking agents – a case study
Students are given the results from an investigation into the effect of an anti-caking agent on the flow of cocoa powder. These results can be used to illustrate the modification of powder flow if the investigation in AC1 is not performed.
Citric acid
Foods like oranges, lemons, yogurt and apples have a sharp taste because they contain naturally occurring acids. Citrus fruits contain citric acid, apples contain malic acid and yogurts are rich in lactic acid. In this text-based activity, students summarise the functions and uses of citric acid as a food additive.
Baking scones
Foods containing flour must be baked before they can be eaten, to enable the starch in the flour to become digestible. Cakes and bread contain a raising agent that contains an acid and an alkali. These react to liberate carbon dioxide, which makes the baking flour rise.
Students investigate different combinations of raising agents in the baking of scones.
Acids and alkalis in foods
The reactions between acids and alkalis are important in the production of food.
Sherbert contains citric acid and sodium bicarbonate. These react to form the characteristic fizz of sherbert on the tongue.
Acids can be found in many drinks. Fruit juices and carbonated drinks are tested to find their pH.
Boiling dumplings
Students carry out practical activities to investigate raising agents, and how they are affected by different pH. Carbon dioxide is needed to make the dumplings rise, and students find that a combination of acid and alkali is necessary to give acceptable results.
Website update
During the end of July 2018 and early August the UYF website was re-built with a new layout, some new content and many new or revised images.
The old design was specifically aimed at school children but the new site reflects the change of approach and caters more for the teacher rather than the student.
Hooray for technology!!
Reactions between acids and alkalis
Citric acid and sodium bicarbonate are dissolved in water to give two commonly used solutions in the food industry.
The pH of these solutions is measured and their reaction observed when mixed together.
The level of acid in a range of drinks is then measured. An extension activity is included