 Ice cream is a colloid, a type of emulsion. An emulsion is a combination of two
substances that don't normally mix toget...
 Frozen dessert usually flavoured with fruit, made from water, sugar, flavourings, and
milk or cream.
 Egg white or gela...
 Colligative property
 Freezing mixture
 Ice crystals
 Interfering substance
 Milk fat or butter fat
 Milk solids
 ...
 To identify the water content of ice
cream and sherbet mixtures and relate
this to freezing rate
 To understand the eff...
 Influence the freezing temperature of water.
 Addition of a non-volatile solute like salt and sugar the freezing point ...
 Created when the water-content in the
base starts to freeze
 Gives solidity and body.
 The size of the ice crystals la...
 Often in the form of butter (milk) fat.
 Adds richness, stabilises the base mix, improves density and the smoothness of...
 Sugars, honey or syrups
 Adds sweetness but also
improves texture and body.
 Lowers the freezing point of the
mix, ens...
 The invisible (and cheapest) ingredient in ice cream.
 The tiny air cells whipped into the base mix are largely respons...
 Usually so-called non-fat milk solids, such as proteins and mineral
salts, and flavourings such as cookie-crumbles.
 Co...
 added to the ice cream base – one or more ingredients that help the other “unwilling”
ingredients to combine.
 Egg yolk
 Improve the structure and texture by keeping down the growth-rate of the ice crystals
of the ice cream
 Reduce the melt...
A well frozen appearance
Absence of large ice particles
A pleasing blend of banana with lemon or lime rind, a subtle
ac...
 Introduction to Food Preparation by Guzman, M.P. and Fojas de Luna, M.V.
 http://www.icecreamnation.org
 Chemisrty: Th...
Crystallization of Ice in Frozen Desserts
Crystallization of Ice in Frozen Desserts
Crystallization of Ice in Frozen Desserts
Crystallization of Ice in Frozen Desserts
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Crystallization of Ice in Frozen Desserts

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The science behind ice cream making.

Published in: Business, Self Improvement
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Crystallization of Ice in Frozen Desserts

  1. 1.  Ice cream is a colloid, a type of emulsion. An emulsion is a combination of two substances that don't normally mix together. Instead, one of the substances is dispersed throughout the other.  In ice cream, molecules of fat are suspended in a water-sugar-ice structure along with air bubbles.  The presence of air means that ice cream is also technically a foam.
  2. 2.  Frozen dessert usually flavoured with fruit, made from water, sugar, flavourings, and milk or cream.  Egg white or gelatin may be added to ensure a fine texture.
  3. 3.  Colligative property  Freezing mixture  Ice crystals  Interfering substance  Milk fat or butter fat  Milk solids  Non-fat solids  Nucleation  nuclei  Overrun  Rate of freezing  Stabilizer  Viscosity
  4. 4.  To identify the water content of ice cream and sherbet mixtures and relate this to freezing rate  To understand the effect of sugar concentration on the depression freezing point of water in ice cream and sherbets.  To understand the effect of a mixture of salt and ice which surrounds a container of mixtures of ice cream and sherbets in the freezing process.  To appreciate the significance of agitation during freezing, its effect on the structure of the frozen mixture, and overrun and its role in breaking up large ice crystals to form a smooth- textured product.  To appreciate the significance of stabilizers in maintaining the size of crystals and the firm body of the frozen product.
  5. 5.  Influence the freezing temperature of water.  Addition of a non-volatile solute like salt and sugar the freezing point drops in proportion to the amount of dissolved substances and for an ionisable one, in proportion to the dissociated ions.
  6. 6.  Created when the water-content in the base starts to freeze  Gives solidity and body.  The size of the ice crystals largely determines how fine, or grainy, the ice cream eventually turns out.  The main objective (apart from the freezing itself) is therefore to keep the size of the ice crystals down as much as possible.
  7. 7.  Often in the form of butter (milk) fat.  Adds richness, stabilises the base mix, improves density and the smoothness of texture and generally increase flavours
  8. 8.  Sugars, honey or syrups  Adds sweetness but also improves texture and body.  Lowers the freezing point of the mix, ensuring that the ice cream does not freeze rock-solid
  9. 9.  The invisible (and cheapest) ingredient in ice cream.  The tiny air cells whipped into the base mix are largely responsible for the general consistency of ice cream, and greatly affect texture and volume.  “Over-run” is the technical term used to indicate how much air an ice cream holds; since air is free and increase the volume, non-premium commercial ice creams could well have an overrun sometimes even exceeding 100 %.
  10. 10.  Usually so-called non-fat milk solids, such as proteins and mineral salts, and flavourings such as cookie-crumbles.  Contribute to the body, texture and smoothness.  More solids means less “free-roaming” water in the ice cream – which in turn usually means less unwanted, large ice crystals in the ice cream.  Too little solids, the ice cream often tends to become unpleasantly icy.  Too much solids, however, may bring about an unpleasantly sandy-like sensation.
  11. 11.  added to the ice cream base – one or more ingredients that help the other “unwilling” ingredients to combine.  Egg yolk
  12. 12.  Improve the structure and texture by keeping down the growth-rate of the ice crystals of the ice cream  Reduce the melt-down speed of the ice cream.  Gelatin, egg whites
  13. 13. A well frozen appearance Absence of large ice particles A pleasing blend of banana with lemon or lime rind, a subtle acid taste which complements the bland banana flavor
  14. 14.  Introduction to Food Preparation by Guzman, M.P. and Fojas de Luna, M.V.  http://www.icecreamnation.org  Chemisrty: The Central Science by Brown and Le May
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