Dry products used in comparatively small quantities, such as whey powder, stabilizers and emulsifiers, cocoa powder, etc., are usually delivered in bags. Sugar and milk powder can be delivered in containers. Liquid products such as milk, cream, condensed milk, liquid glucose and vegetable fats are delivered by tankers.
The ingredients used in ice cream production line are: fat；milk solids-non-fat (MSNF)；sugar/non-sugar sweetener；emulsifiers/stabilizers；flavouring agents；colouring agents.
-Weighing, measuring and mixing:
Generally speaking, all dry ingredients are weighed, whereas liquid ingredients can be either weighed or proportioned by volumetric meters.
-Homogenization and pasteurization:
The ice cream mix flows through a filter to a balance tank and is pumped from there to a plate heat exchanger where it is preheated to 73 – 75C for homogenization at 140 – 200 bar, the mix is pasteurized at 83 – 85C for about 15 seconds then cooled down to 5C and transferred to an ageing tank.
The mix must be aged for at least 4 hours at a temperature between 2 to 5C with continuous gentle agitation. Ageing allows time for the stabilizer to take effect and the fat to crystallize.
•to whip a controlled amount of air into the mix;
•to freeze the water content in the mix to a large number of small ice crystals.