|dc.description.abstract||1. Plain Ice Cream: In plain ice cream (control) as the per cent of fat is increased the cream becomes softer. Butter fat, combined wiith other material than milk solids, changes the crystallization and produces a stiff cream. When too much fat is present whipping takes place producing a cream that is soft and which melts more rapidly than when a medium amount of fat is used.
The decrease in hardness is noticed slightly between 8% and 19% plain cream. 30% plain cream showed a much softer cream than 8% or 19% cream.
In plain ice cream the presence of fat increases the power to resist melting. This resistance is most noticeable between the melting of the 8% end 19% cream. 30% cream shows the power to resist melting to a less degree.
2. Cream containing gelatin: Gelatin in a large or small quantity produces similar effects, depending upon the per cent of cream used. The power to withstand pressure and the melting resistance increases as the amount of gelatin increases when compared with the control cream with a similar fat content.
The hardest and most heat resistant cream is produced with a medium per cent of fat and a large amount of gelatin.
Here too, as in the control cream, fat is essential to produce hardness and melting resistance until a point is reached where whipping affects the texture. After whipping begins the incorporated air reduces the hardness and melting resistance.
Four ounces of gelatin give about the same hardness as four ounces of corn starch but it is much better, producing a smoother cream which is more stable under ordinary conditions.
Compared with all other creams used, cream in which gelatin is used has the greatest ability to withstand heat and is the hardest.
3. Cream Containing Gum Tregacanth: Gum tragacanth with a low per cent of fat produces a cream that is slightly harder, with slightly more power to resist heat than plain cream.
As the per cent of fat is increased the power to resist pressure and heat decreases falling below plain cream, showing gum tragacanth acts as a filler and not as a binder.
The hardness and melting resistance of cream containing gum tragacanth decreases as the per cent of fat increases. The reverse is true with gelatin to a point where whipping is very noticeable.
Cream containing gum tragacanth becomes softer and melts more rapidly as the per cent of fat is increased. Corn starch increases the hardness and power to resist heat as the per cent of fat is increased until a point is reached where the whipped condition effects the texture.
Its most noticeable effect on the texture of ice cream, because of the nature of the gum, is to impart a smoothness which becomes slimyness when large quantities are used.
4. Cream Containing Corn Starch: When corn starch is used as a filler slight increase in hardness and melting resistance is noticeable with 19% cream compared with 8%. Whipping is very noticeable with the 30% cream.
Cream containing corn starch is harder and more resistant to heat than plain cream of the same per cent fat.
Corn starch compares favorably with a similar amount of gelatin the starch cream being more granular than the gelatin cream.
Corn starch produces a coarse granular cream, while gum tragacanth produces a smooth soft cream.
The most noticeable effect of starch is, the cream is very light due to the whipped condition. This is noticeable in each per cent of cream.||en