Applications of Biotechnological Processes

1
Applications of Biotechnological Processes

• The Food Industry and Fermentation

2

• Dairy Products
• Yeast Extract Products
• Fruit Produce

3
Dairy Products

• Microbes are used to make cheese, butter, yoghurt
  and sour cream.
• Traditional Method
• Products were produced through the action of
  indigenous bacteria present in milk.

4
Modern Method

• Milk is pasteurised to ensure safety for human
  consumption (kills indigenous bacteria).
• Microbial cultures are added to the milk.
• Bacteria convert the lactose in milk to lactic
  acid (lower pH). Bacteria are referred to as
  lactic acid bacteria e.g. Lactobacillus or
  Bifidobacterium

5

• A lowering of the pH results in the protein in
  milk clotting and a release of flavours and
  aromas. A lower pH also reduces the likelihood of
  contamination.
• The specific bacteria used will determine
  specific properties, textures and aromas in the
  final product. Sometimes a second inoculum of
  bacteria is added to create the final, desired
  product

6
Functional Foods

• Functional foods are those which provide health
  benefits beyond basic nutrition.
• e.g. novel fermented drinks (also known as
  probiotics) provide several health benefits

7

• Probiotics contain live cultures that can
  re-establish themselves in our gut flora to
  return the individual to full health. They often
  do this by competing with disease causing gut
  flora for nutrients and by producing chemicals
  that will inhibit pathogen growth.
• Examples Bio-yoghurts
• Some probiotics can shorten the duration of
  infant viral diarrhoea

8

• Probiotic bacteria are able to establish
  themselves in the gut and synthesise vitamins.
  These vitamins can be absorbed through the
  individuals gut wall and taken up by the
  bloodstream.
• Probiotics and nutraceuticals are believed to
  have some anti-cancer properties, have the
  ability to reduce cholesterol and improve an
  individuals intolerance to lactose.
• (nutraceuticals- food ingredients that
  provide health benefits)

9
Yeast Extract Products

• Yeast is used to produce alcoholic drinks, make
  yeast extracts (found in Bovril and Marmite) and
  to make food flavourings.
• Yeasts have a useful property known as autolysis.
• This is a process that results in the yeast
  producing enzymes that degrade itself, thus
  releasing particular flavours.
• Example peptidase production and subsequent
  protein hydrolysis will create beef flavour

10

• The flavour released depends on the enzyme, the
  stage in the yeast cell cycle and the age of the
  culture.
• Yeast flavourings are found in crisps, soups and
  other packet foods

11
Fruit Produce

• Fruit is used to make fruit juices, enzymes are
  added in their production to clarify the juice.
• Pectinases
• are produced by fungi
• Pectin holds/binds cell walls together, it is
  extracted during the fruit pressing stage in
  juice making.
• Pectin is highly viscous and can lead to problems
  with clarification and juice filtration
• Adding pectinase hydrolyses the pectin polymer to
  individual carbohydrate units

12

• Arabanase
• Araban is also a polymer found in cell walls, it
  is extracted during the fruit pressing stage in
  juice making.
• It creates a haze in the pressed juice.
• Adding arabanase removes the hase.

13

• Amylases
• Starch in pressed juice can be removed by adding
  amylases.

14

• Fruit is also sold as itself e.g. tomatoes.
  Transgenic Favr Savr tomatoes have been
  engineered to not express a gene whose protein
  causes the softening of fruit.
• Protein name polygalacturonase (degrades pectin
  within the fruit causing it to soften)

• The engineered process

15
Original Tomato DNA
16

• Advantage of producing tomatoes this way
• Tomatoes are able to ripen on the vine without
  softening and bruising. This gives them a longer
  shelf life.
• This also increases the number of tomatoes that
  are suitable to be sold, thus increasing profits/
  reducing costs lost to spoilage.

17
Past Paper Questions

• 2006 Q1
• 2006 Q3
• 2005 Q1
• 2003 Q1