Enzymes

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Enzymes
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Overview

• Enzymes -- proteins that catalyze a specific
  chemical reaction.
• Each enzyme is specific to a specific chemical
  reaction.
• The substance on which an enzyme acts is known as
  a substrate.
• The structure of the enzyme does not change as a
  result of the reaction.

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Key Functions of Enzymes

• Ripen fruits and vegetables.
• Spoil fruits and vegetables after harvest.
• Change flavor, color, texture, and nutritive
  value of food.
• Decrease shelf-life if not inactivated.
• Extract and purify commercially to
• Break down starch
• Tenderize meat
• Clarify wines
• Coagulate milk

B-3.03 -- Enzymes
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Naturally-Occurring Enzymes

• Trigger enzymatic browning
• Found in large amounts in
• pineapple
• papaya
• figs
• Meat tenderizers made from compounds in fruit
• Bromelain -- Pineapple
• Papain -- Papaya
• Ficin -- Fig

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Enzymatic Reaction
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Factors that Affect Enzyme Activity

• Two factors will affect enzyme activity
• water availability
• amount of substrate
• Enzymatic reactions generally occur in the
  presence of water.

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Water Availability

• Water acts as a reactant and solvent in enzymatic
  reactions.
• Less water available the slower the enzymatic
  reaction.
• Reactions occur more slowly in dried foods (dried
  milk) than in moist foods (fluid milk).

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Amount of substrate

• Substrate is molecule upon which enzyme acts.
• Substrate binds with the enzyme's active site and
  enzyme-substrate complex formed.
• More substrate in a solution, the greater the
  rate of the reaction
• Enzymes have more product with which to react.