제품 ≫ I/C ≫ IC 품질

- Flavor defect

- Texture defect

- Melting quality

- 빙결정 성장

Melting Quality Characteristics

1. Curdy Melt-Down: May be due to visible fat particles or due to coagulation of
the milk proteins so is affected by factors that influence fat destabilization
or the protein stability such as:

• High acidity (protein coagulation).
  
• Salt balance (protein coagulation).
  
• High homogenizing pressures (fat coagulation).
  
• Over-freezing in the freezer (fat coagulation).

2. Does not Melt: See ice cream structure,
under the section on melt-down and fat structure/destabilization. May be caused by:

• Over emulsification.
  
• Wrong emulsifier.
  
• High fat.
  
• Excessive fat clumping in the mix due to homogenization at too low a
  temperature or single-stage homogenizer.
  
• Freezing to too low a temperature at freezer.

3. Wheying off: The salt balance, protein composition, and carrageenan addition
(or lack or it) all are factors.

Colour Defects

1. Colour Uneven:
Applies usually to ice cream in which colour has been used, but may be noticed
in vanilla ice cream under some circumstances.

2. Colour Unnatural:

• Wrong shade of color used for flavoured ice cream.
  
• Too much yellow coloring used in vanilla ice cream.
  
• Grayish color due to neutralization.

Shrinkage

A very troublesome defect in ice cream
since there appears to be no single cause or remedy. Defect shows up in hardened
ice cream and manifests itself in reduced volume of ice cream in the container
usually by pulling away from the top and/or sides of container. Structurally, it
is caused by a loss of spherical air bubbles and formation of continuous air
channels. Some factors believed associated with the defect are:

• Freezing and hardening at ultra low temperatures.
  
• Storage temperature. Both low and high appear to contribute.
  
• Excessive overruns.
  
• Pressure changes, for example, from altitude changes (lids popping when
  shipped to high altitudes, shrinkage when returned to low
  altitudes).

NOTE: Retailing: More so than other frozen
products, ice cream requires constant, uninterrupted freezing cycle at low
temperatures to avoid problems. Problems at retail level can arise from
overfilling of display cabinet, heat from display lamps. hot air from
incorrectly positioned circulation fans, displaying ice cream together with
semi-frozen goods.