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Food Science

Sweeteners and thickeners

Very useful site on additives covered in this topic.


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A.5.1 Describe the role of sugar and artificial sweeteners in the design of food products.

Sweetness is an important characteristic of many food products. Sweetness can be imparted by sugar or artificial sweeteners. However, sugar provides other benefits to food products. It contributes to the mouth feel of products and to their storage properties. Consider low-sugar fruit squashes.

A.5.2 Identify two artificial sweeteners.

Consider saccharin and aspartame.

Is used as a artificial sweeteners even though it has a bitter or metallic after taste. It is used on drinks, candies, toothpastes and medicines. It effectively produces no kind of food energy for the human body, but tastes sweeter then sucrose.

A.5.3 Describe the role of thickeners in the design of food products.

Consider protein gels and starch gels.
  • Used in aqueous substances to alter its viscosity, e.g. starches added to make gravies thick.
  • It adds 'body' or increases its viscosity
  • does not noticeably change other properties such as tatse.
Corn starch is an inexpensive ingredient to thicken sauces and gravies or any other cooked recipe Beef Gelatin is used in sweets, ice cream and sausages.

Preservatives, antioxidants and emulsifiers

A.5.4 Describe the function of Preservatives in food.

Improve the shelf life of food

  • inhibit the growth of microbes (physiological spoilage)
  • inhibit oxidation of food (chemical spoilage)

A.5.5 List two commonly used food preservatives.

Chemical Affected Organism(s) Action Used in Foods
Sulfites Insects & Micro-organisms Anti-oxidant Dried Fruits, Wine, Juice
Sodium Nitrite Clostridia Anti-microbial Cured Meats
Propionic Acid Moulds Anti-microbial Bread, Cakes, Cheeses
Sorbic Acid Moulds Anti-microbial Cheeses, Cakes, Salad Dressing
Benzoic Acid Yeasts & Moulds Anti-microbial Soft Drinks, Ketchup, Salad Dressings

from http://www.foodadditivesworld.com

A.5.6 Describe the role of antioxidants in foods.

For example, the use of ascorbyl palmitate to prevent rancidity of vegetable oils.

Antioxidants are added to food to slow the rate of oxidation

  • they can extend the shelf life of the food
  • such as ascorbyl palmitate to prevent rancidity of vegetable oils

A.5.7 List two commonly used antioxidants.

Antioxidant Typical foods
Ascorbyl palmitate Beers, cut fruits, jams, dried potato. Helps to prevent cut and pulped foods from going brown by preventing oxidation reactions that cause the discolouration. Can be added to foods, such as potato, to replace vitamin C lost in processing.
Tocopherols Oils, meat pies. Obtained from soya beans and maize. Reduces oxidation of fatty acids and some vitamins.
Butylated hydroxyanisole (BHA) Oils, margarine, cheese, crisps. Helps to prevent the reactions that break down fats and cause the food to go rancid .
Citric acid Jam, tinned fruit, biscuits, alcoholic drinks, cheese, dried soup. Naturally-occuring in citrus fruits like lemons. Helps to increase the anti-oxidant effects of other substances. Helps to reduce the reactions that can discolour fruits. May also be used to regulate pH in jams and jellies.

from http://www.understandingfoodadditives.org

A.5.8 Describe an emulsion.

Emulsion is a mixture of water and oil.

  • When left alone to stand the oil separates out.

Mayonnaise with and without emulsifiers Mouse over the image

A.5.9 List two examples of food emulsions.

A.5.10 Describe the role of emulsifiers in stabilising food emulsions.

Emulsifiers can help to make a food appealing.

  • keeps the aqueous mixture stable
  • prevents the oil and water from separating

A.5.11 List two commonly used emulsifying agents.

  • lecithin
  • mono- and di-glycerides of fatty acids

References

Bulleted list and italicised paragraphs are excerpted from Design Technology: guide. Cardiff Wales, UK: International Baccalaureate Organization, 2007.

Images are clickable links to its location.

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Page last modified on January 14, 2013, at 03:54 AM