ICE REAM MANUFACTURE
ICE REAM MANUFACTURE
Ice cream ManufacturProcedure of process:Blending of the mix
ingredientsPasteurizationHomogenizationAging the
mixFreezingPackagingHardening
Figure 1. Block diagram of ice cream production
ICE CREAM PRODUCTION PLANT
Figure 1. Plan of ice cream manufacture
BlendingThe milk fat source, nonfat solids, stabilizers and
emulsifiers are blended to ensure complete mixing of liquid and dry
ingredients
Pasteurization of MixPasteurization is the biological control
point in the system, designed for the destruction of pathogenic
bacteria. In addition to this very important function,
pasteurization also reduces the number of spoilage organisms such
as psychrotrophs, and helps to hydrate some of the components
(proteins, stabilizers).Pasteurization (Ontario regulations): 69
C/30 min. 80 C/25s
Homogenization of Mix
Homogenization provides the following functions in ice cream
manufacture:Reduces size of fat globulesIncreases surface areaForms
membranemakes possible the use of butter, frozen cream, etc.By
helping to form thefat structure, it also has the following
indirect effects:makes a smoother ice creamgives a greater apparent
richness and palatabilitybetter air stabilityincreases resistance
to melting
Ageing of MixAging is performed in insulated or refrigerated
storage tanks, silos, etc. Mix temperature should be maintained as
low as possible without freezing, at or below 5 C. An aging time of
overnight is likely to give best results under average plant
conditions. A "green" or unaged mix is usually quickly detected at
the freezer.Ice cream mix is aged at 40F (5C) for at least 4 hours
or overnight. Aging the mix cools it down before freezing, allows
the milk fat to partially crystallize and the gives the proteins
stabilizers time to hydrate. This improves the whipping properties
of the mix.
Freezing/Whipping of Ice Creamthe mix is drawn into a flavour
tank where any liquidflavours, fruit purees, or colours are added.
The mix then enters thedynamic freezing processwhich both freezes a
portion of the water and whips air into the frozen mix. The
"barrel" freezer is ascraped-surface, tubular heat exchanger, which
is jacketed with a boiling refrigerant such as ammonia or freon.
Mix is pumped through this freezer and is drawn off the other end
in a matter of 30 seconds, (or 10 to 15 minutes in the case of
batch freezers) with about 50% of its water frozen. There are
rotating blades inside the barrel that keep the ice scraped off the
surface of the freezer and also dashers inside the machine which
help to whip the mix and incorporate air.
HardeningHardening enables fast freezing, which achieves the
desired ice cream texture by limiting the growth of ice crystals
and air bubbles.The ice cream is cooled as quickly as possible down
to a holding temperature of less than -13F(-25C). The temperatures
and times of cooling will depend on the type of storage freezer.
Rapid cooling will promote quick freezing of water and create small
ice crystals. Storage at -13F(-25C) will help to stabilize the ice
crystals and maintain product quality. At this temperature there is
still a small portion of liquid water. If all the water present in
the ice cream were frozen, the ice cream would be as hard as an ice
cube
Proses Flow Diagram Pembuatan Ice Cream
