Preparation of Ice Cream Mix

Ice cream is composed of a mixture of both dairy and non-dairy food ingredients such as milk products, sweetening agents, stabilizers, emulsifiers, flavours and colouring materials. As already seen earlier, wide variety of ingredients could be used to produce ice cream mix. The effect of these ingredients upon the finished product is due to the constituents of the ingredients.

An ice cream mix is the unfrozen blend of the different ice cream ingredients. It consists of all the ingredients of ice cream with the exception of flavour material and air. Flavour is added only at the time of freezing and air is incorporated into the mix during freezing. The composition of ice cream is usually expressed as percentage of its constituents. A satisfactory composition produces an ice cream having desired flavour body and texture characteristics. An ice cream mix with such a satisfactory composition is called a “Balanced mix”. Thus a balanced ice cream mix is one in which the proportions of the constituents and ingredients are such that they combine to produce an ice cream of satisfactory quality.

i) Calculation of Mix-Ingredients: To prepare ice cream mix various ingredients are mixed. It is necessary to know how much of each ingredient should be added to produce a balanced mix. Addition of exactly calculated amount of ingredients will help to produce ice cream of uniform quality. This will also ensure ice cream produced meets the legal standards prescribed for ice cream.Knowledge of calculation, therefore, is helpful in properly balancing the ice cream mix.

Algebraic method is one method for calculating the amount of ingredients required for ice cream preparation.

The final composition desired in ice cream is decided first. Suppose ice cream with the following composition is to be prepared:

Fat	12.0%
SNF	– 11.0%
Sugar	– 15.0%
Stabilizer & Emulsifier	v 0.5%
Total	= 38.5%

The ingredients available are:

Milk	3.5% fat; 8.5% SNF
Cream	– 40.0% fat; 5.28 SNF
Skim milk powder	– 1.0% fat; 96.0% SNF
Sugar, Stabilizer + Emulsifier	– It is assumed that sugar, stabilizer and emulsifier contribute 100% solids.

It is convenient to calculate the required amount of ingredients for preparing 100 kg of ice cream mix.

ii) Calculation for 100 kg Ice cream mix: Since sugar and stabilizer + emulsifier in the mix are 15.0% and 0.5% respectively, the ice cream mix will have 15.0 Kg sugar and 0.5 Kg stabilizer + emulsifier. It means that out of 100.0 Kg of mix, 15.5 Kg comes from the mixture. The balance of (100 –15.5) kg== 84.5 Kg comes from the mixture of milk, cream and skim -milk powder.

Assume A Kg milk, B Kg cream and C Kg skim-milk powder are used.The values for A, B and C could be calculated by forming algebraic equation and solving the equation.

In 100 Kg ice cream mix the following will be there:

Milk	– A Kg
Cream	– B Kg
Skim milk powder	– C Kg
Sugar	– 15.0 Kg
Stabilizer + emulsifier	– 0.5 Kg
Total	= 100 Kg

A + B + C + 15.0 + 0.5 = 100.0

or A + B C = 100.0 – (15.0 + 0.5)

or A + B C = 84.5 — Equation (1)

In 100 Kg of mix 12 Kg milk fat (12%) is present. This amount comes from A Kg milk, B Kg cream and C Kg skim milk powder. Since the fat percent in each ingredient is known an equation for fat can be made.

(3.5)/100 *A +(40)/(100)*B+(1.0)/(100)*C =12

Or  3.5 × A + 40.0 × B + 1.0 × C = 1200 Equation (2)

Similarly equation for SNF content is formed:

(8.5)/(100)*A+(5.28)/(100)*B+(96.0)/(100)*C =11

8.5   5.28   96.0

or 8.5 × A + 5.28 × B + 96.0 × C = 1100 Equation (3)

To eliminate one known value (Say A) multiply the equation (1) by 3.5

i.e. 3.5 (A + B + C) = 84.5 × 3.5

or  3.5 × A + 3.5 × B + 3.5 × C = 84.5 × 3.5 = 295.75

Subtract this equation from equation (2)

3.5 × A + 40.0 × B + 1.0 × C = 1200.00

3.5 × A + 3.5 × B + 3.5 × C = 295.75

36.5 × B – 2.5 × C = 904.25 Equation (4)

Similarly to eliminate A from equation (3) multiply equation (1) by 8.5 and subtract from equation (3).

8.5 (A+B+C) = 84.5 x 8.5

or 8.5 x A + 8.5x B + 8.5 x C = 84.5 x 8.5 = 718.25

8.5 A + 5.28 x B + 96.0 x C = 1100

8.5 A + 8.50 x B + 8.5 x C = 718.25

3.22 × B + 87.5 × C = 318.75 Equation (5)

To eliminate B, multiply equation (4) by 3.22 and equation (5) by 36.5

 3.22(35.5 × B – 2.5 × C) = 3.22 × 904.25(Equation 4)

36.5(-3.22 × B - 87.5 × C) = 35.5 × 318.75(Equation 5)

or 3.22 × 35.5 × B – 8.05 × C = 2911.685 —- Equation (6)

36.5 × 3.22 × B + 3193.75 C = 13933.875 —- (Equation (7)

3185.70 C = 16845.56

∴ 3185.70 C = 16845.56

C = 16845.56

—————    = 5.28

3185.70

Quantity of skim milk powder required = 5.28

Substitute the value of C (= 5.28) in equation (4)

∴ 36.5 x B – 2.5 x 5.28 = 904.25

or 36.5 x B – 13.20 = 904.25

or 36.5 x B = 904.25 + 13.20

36.5 x B =  917.45

or B =         917.45

                    ————    = 25.13

                     36.5

 Quantity of Cream required = 25.13 Kg

Substitute the value of C (=5.28) & B (=25.13) in equation (1)

 A + 25.13 + 5.28 = 84.5

or A = 84.5 – (25.13 + 5.28)

       = 54.09

 Quantity of Milk required = 54.09 Kg.
Proof Sheet: 100 Kg of ice cream mix will have the following ingredients: