Composition

The differences between soft serve and regular ice cream include:

•  Composition
•  Freezing procedures
•  Stability and whipping properties of the mix
•  Maintenance of dry, smooth, stiff characteristics of the product as drawn from the freezer.

i) Fat: Soft serve ice cream has a lower butter fat than the hard product, but it is difficult for the consumer to tell because the soft state allows full flavour. Soft serve ice cream normally has a fat content between 6 to 10% range. If fat content is low, i.e. less than 4%, the product tends to become coarse, weak and icy. If the fat content is high (above 12%) freezing problem is encountered.This involves possible fat separation, and also, the product becomes too rich and less palatable.

ii) Milk Solids-Not-Fat (MSNF): The MSNF content of soft frozen products varies somewhat inversely with the fat content and can be as high as 13% for a low fat formula. MSNF serves for provide proper firmness of body. In products having a high MSNF content, the lactose may separate during freezing and cause a sandy defect. Normally soft serve products consists of 11-14% MSNF.

Soft serve mixes should have a slightly lower MSNF than normal ice cream, as a slightly lower MSNF (MSNF factor 16-16.5) contributes to a higher degree of fat destabilization, thus, ensuring better stand-up and slower meltdown (a MSNF factor of 17 is recommended for plain, hardened ice cream).Since the soft-serve mix is exposed to a mechanical treatment for alonger period of time in the freezer, this can cause excessive churning of fat, resulting in a greasy texture. This can be avoided by incorporating whey proteins which impart greater stability to fat emulsion, and consequently less fat destabilization and ‘churning out’ effect of the emulsifier. Replacement of 10-15% MSNF with whey powder adds to the freshness of soft-serve ice cream and fat destabilization is also brought under control.

iii) Sugar: The sugar content of soft serve products is 13-15%, which is slightly lower than for regular ice cream. The amount of corn sugar used to replace cane sugar is limited to about 25% in order to avoid too low a freezing point.However, corn syrup solids, instead of corn syrup, can be added as they provide firmness and also raise the freezing point slightly (corn syrup solids depress the freezing point less than corn syrup and sucrose) thereby enabling the drawing of ice cream at almost the same temperature as normal ice cream.Stiffness and dryness of mix is extremely important for getting a smooth, creamy finished product from the soft serve freezer. Those characteristics are achieved by two ways:

•  By reducing the sugar content of mix by 2-3% of that used for a hard ice cream product
•  Drawing the product at lower temperature 21 to 22 F. This lower temperature not only produces a stiffer product, but makes it immediately suitable for serving to public.

 iv) Emulsifiers and stabilizers: Higher amounts of emulsifiers and stabilizers are added to provided desirable whipping properties, smoothness, firmness and melting resistance.

Emulsifiers have several main effects in ice cream:

•  To facilitate the dispersion of the fat in fine, uniform globules during whipping
•  To promote and control destabilization of the fat and to secure a good fat protecting membrane around the air cells
•  To aid aeration during freezing by permitting better air distribution with a smaller air cell size.

 Thanks to these effects an ice cream with a creamy consistency, slow meltdown and improved storage stability can be produced. These are exactly the properties that are needed in scoopable ice cream. It is advantageous to increase the addition of emulsifier in scoopable ice cream, due to increased level of the liquid water phase at any given temperature.

The main effect of stabilizers in ice cream systems is to bind water resulting in higher mix viscosity and superior body in the finished ice cream as well as controlling the mobility of the residual aqueous phase. As mentioned above,there is more liquid phase in scoopable ice cream, which means that more stabilizer is needed to bind the water present. A 5 to 10% increase in emulsifier/ stabilizer content is advisable.

v) Other additives: Products like calcium sulphate can be used at the rate of 0.12% to produce dryness and stiffness in ice cream.