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PREPARATION OF SOFTY ICE-CREAM
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Ice cream is also accepted as a nutritious food for the aged, sick and convalescing. Generic educational campaigns need to be carried out to create a better awareness of ice cream as a healthful and hygienic food that can be consumed throughout the year.
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Milk contains 3.5% fat, 9% SNF, where as ice cream contains 10-11% fat, 11-12% SNF. Fat content is increased to by addition of cream or butter. SNF content is increased by addition of skim milk powder or WPC or protein replacers. To stabilise the mix and to prevent the ice crystal formation stabilizers like sodium alginate at a level of 0.3% is used. For better whipping ability emulsifier like glyceryl monostearate (G.M.S) is added at a level of 0.2%. For sweetness, sugar is added up to 15%. Equipments like Batch freezer or softy Ice cream freezer, pasteurizing and ageing vats and homogeniser, deep freezer are required
Ingredients
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Whole milk, Cream, butter, oils, skim milk powder, emulsifier (glycerol mono stearate), stabilizer (CMC, sodium alginate, guargum, gelatin), sweetening agents (cane sugar) dried fruits and nuts, total solid replacers etc.
Procedure
This includes three steps:
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Calculating / Figuring the mix
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Preparing the mix
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Freezing the mix
Figuring the mix / Calculation of mix
Thus the optimum SNF for a mix containing 10% fat, 15% sugar and 0.5% combined emulsifier/stabilizer would be
36 – (10 + 15 + 0.5) = 10.5%
The simplest situation is that in which all of the fat and all of the SNF is derived from single ingredients (eg. Butter and skim milk powder). Butter has a fat content of 80% and skim milk powder has a SNF content of 97% (the small amounts of SNF contributed by butter and fat contributed by skim milk powder may be ignored). Thus for the basic formula discussed above the quantities of each ingredients may be determined by simple developing algebraic equations with variable “X” for whole milk, “Y” for Skim milk or powder and “Z” for cream etc. Thus for three variables three equations can be formed as
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Fat equation [ X(Fat % in Milk)+ Y(Fat % in SMP)+ Z(Fat % in Cream = 10 ]
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SNF equation [ X(SNF % in Milk)+ Y(SNF % in SMP)+ Z(SNF % in Cream = 10.5 ]
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Weight equation
{ X+ Y+ Z+ % of Sugar +% of stabilizer + % of Emulsifier = 10 }
By solving equations 1, 2 and 3 the unknown variables of milk, milk powder, cream etc can be algebraically calculated.
Preparing the mix
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There are different ingredients used in preparation of ice cream mix, which include whole milk, skim milk powder, cream, sugar and stabiliser. Cream and stabiliser are heated in the vat at 110oF. At this temperature, dissolve skim milk powder, sugar and stabiliser. Initially they are mixed separately with little quantity of milk and then the mixture is agitated to get a uniform mix without any clumps in a mixer.
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After uniform mixing, the mix can be pasteurised and cooled to room temperature, and then to 5oC. It is maintained at same temperature for 4-6 hours for ageing. After ageing of mix, freezing is done in an ice cream freezer. Colour and essence are added to ice cream mix and measured quantity of the mix is poured into the freezing table. The compressor is started and motor is switched on, which rotates the dasher cum scrapper. The ice cream formed is checked for its consistency and later drawn into container for use.
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Prepared ice cream is packed in wax coated paper cups / plastic cups or edible wafer cones. Knowing the volume of each cone or cup and the number of cups produced total volume of ice cream prepared is arrived at and over run is calculated accordingly.
Sample Ice Cream mix ( ingredients for 1 Litre)
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Milk - 800 ml
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Cream - 140 g.
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Skim milk powder - 50 g.
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Sugar - 175 g.
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Sodium alginate - 3 g.
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(G.M.S.) - 2 g.
Preparation of Ice-cream
Cooling and ageing
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After homogenisation, hot mix is quickly cooled in the surface cooler and transferred to ageing vats for 5-6 hours.
Freezing the mix
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Colour and flavour are added before freezing. The preferable Combination of Flavour and Colour are Green for Pista, Yellow for Mango, Pink for Strawberry and plain colour for Vanilla. The ice cream mix, along with air, is then pumped in to the freezer where it is converted into ice cream. This process calls for simultaneous whipping and freezing. High speed blades in the freezer whip the mix and air together to form a creamy mix. It is at this stage that fruits, nuts and other ingredients are added.
Over run in ice cream
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Although frozen, the ice cream is soft enough to be poured into cones or cups or moulds at different shapes. Ice cream would not be ice cream but for the air, without this aeration, the finish product would be a solidly frozen mass which just could not be eaten. Whipping air into the mix helps make sure that ice creams is smooth and easy to scoop. This exertion is called “Over run”.
Hardening and storage
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Character
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Score Card
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| Flavour and odour
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45
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| Body and texture
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20
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| Melting resistance
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20
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| Packing
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15
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| Total
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100
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Resuts and comments
Over run = -------------
Kulfi
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Kulfi is the indigenous ice cream frozen in small containers. Usually consumed in summer and also called malai kulfi.
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Method of Preparation: Milk is sweetened by addition of sugar to boiling milk and the product is concentrated to approximately 2:1. When the concentrate has cooled, malai (indigenous cream), crushed nuts and the desired flavour are added and then well stirred. The mix is placed in conical or cylindrical moulds of various capacities made of galvanized iron sheets or cylindrical earthenware pot. The moulds are closed on top by means of a small disc and the edges made air tight with wheat dough (modern moulds are made of plastic or aluminum, generally conical in shape with screw cap plastic tops). The mix in the moulds is frozen using a large earthen vessel containing a mixture of ice and salt in the ratio of 1:1.
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Participants