DESCRIPTION
Figure schematically shows both batch production in a
churn and continuous production in a butter making machine.
The cream can be supplied by a liquid milk dairy (surplus cream). From the
intermediate storage tank the cream continues to pasteurisation
at a temperature of 95C or
higher. The high temperature is needed to destroy enzymes and micro-organisms
that would impair the keeping quality of the butter. The heat treatment
releases strongly anti oxygenic sulphhydryl
compounds, which further reduce the risk of oxidation.
Vacuum deaeration can also be included in the line if
the cream has an undesirable flavour or aroma, e.g.
onion taste. Any flavouring will be bound in the fat
and transmitted to the butter unless removed. After this the cream is returned
to the pasteuriser for further treatment – heating,
holding and cooling – before proceeding to the ripening tank. In the ripening
tank, the cream is subjected to a temperature program which will give the fat
the required crystalline structure when it solidifies during cooling. The
program is selected to match factors such as the composition of the butter fat,
expressed for example in terms of iodine value, which is a measure of the
unsaturated fat content. The treatment can also be modified to produce butter
with good consistency despite a low iodine value, e.g. when the unsaturated
proportion of the fat is low. Ripening usually takes 12 – 15 hours. Where
possible, the acid producing bacteria culture is added before the temperature
treatment. The quantity of culture added depends on the treatment program
selected with reference to the iodine value.
From the ripening tank the cream is pumped to the continuous butter-maker or
the churn. In the churning process the cream is agitated violently to break
down the fat globules, causing the fat to coalesce into butter grains. The
cream is split into two fractions: butter grains and buttermilk. In traditional
churning the machine is stopped when the grains have reached a certain size,
and then the buttermilk is drained off. Buttermilk drainage is continuous in
continuous butter making machines. After drainage the butter is worked to a
continuous fat phase containing a finely dispersed water phase. If the butter
is to be salted, salt is spread over the surface in batch production, or added
in slurry form during the working stage in continuous butter making. After
salting, the butter must be worked further to ensure uniform distribution of
the salt. The working of the butter also affects the characteristics by which
the product is judged – aroma, taste, keeping quality, appearance and colour. The finished butter is discharged into the
packaging unit and thence to cold storage.
General process steps in batch and continuous production
of butter
1.Milk reception 2.Preheating and pasteurisation of skimmilk 3.Fat separation 4.Cream pasteurization 5.Vacuum deaeration (when used) 6.Culture preparation (when used) 7.Cream
ripening and souring (when used) 8.Temperature treatment 9.Churning/working
(batch) 10.Churning/working (continuous) 11.Buttermilk collection 12.Butter
silo with screw conveyor 13.Packaging machines
BENEFIT
1.Opportunity to realize products with customized recipes.
2.Opportunity to produce more than one product
with the same processing line.
3.High quality of the final product keeping an elevated nutritional value.
4.Wide customization of the final product.
5.Maximum yield, minimum production waste.
6.Highest energy savings thanks to the most advanced technologies.
7.Complete line supervision system through monitoring of every process phase.
8.Recording, visualization and printing of all daily production data.
CONSTRUCTION FEATURES
Working capacity
from 1 tons/d up to 50 tons/d
Products - Sweet
butter
- Sour
butter
- Salted butter
- Package in bulk container, small box