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In butter making, if the cream 5. _____ to the same heat treatment it will be the chemical composition of the milk rat that
determines the butter’s consistency. 6. _____ will make a soft and greasy butter, whereas butter from hard milk fat will be hard and
stiff. If, however the heat treatment suits the iodine value of the fat the constancy of the butter can he optimized. For the
7. _____ regulates the size of the fat crystals, and the relative amounts of slid fat, and the continuous phase – the factors that
determine the consistency of the butter.
Pasteurization causes the fat in the fat globules to liquefy. And when the cream is subsequently cooled a proportion of the fat
will crystallize. 8. _____, the crystals will be many and small; if gradual the yield will be fewer
but larger crystals. 9. _____ the more
solid be the fat that will crystallize to form the solid phase, and the less the liquid fat that can be squeezed out of the fat globules
during churning and working.
The crystals bind the liquid fat 10. _____ Since the total surface area is much greater if the crystals are many and small, more
liquid fat will be adsorbed than if the crystals were larger and fewer. 11. _____, churning and working will press only a small
proportion of the liquid fat from the fat globules. The continuous fat phase will consequently be small and the butter firm. In the latter
case, the opposite applies. A larger amount of liquid fat will be pressed out; the continuous phase will be large and the butter soft.
12. _____ for the cream, it is possible to regulate the size of the crystals in the fat globules and in this way influence both the
magnitude and the nature of the important continuous fat phase.
E x e r c i s e F o u r
. Read the article below and write one word to fill the gap.
Treatment of hard fat
For optimum consistency where the iodine value 1. _____ low, i.e. the butterfat is hard, as much 2. _____ possible of the hardest
fat must 3. _____ converted to as few crystals as possible, so that little of the liquid fat is bound 4. _____ the crystals. The liquid at
phase in the fat globules will thereby be maximized and much of it can be pressed out during churning and
working, resulting
5. _____ butter with a relatively large continuous phase of liquid fat and with the hard fat concentrated at the solid phase.
The program of treatment necessary to achieve this result comprises the following stages:
− rapid cooling to about 8 °C and storage for about 2 hours 6. _____ this temperature;
− heating gently to 20…21 °C and storage at this temperature for at least 2 hours (water at 27…29 °C is used for heating);
− cooling to about 16 °C.
Cooling to about 8 °C causes the formation of 7. _____ large number of small crystals that bind fat from the liquid continuous
phase to their surface.
When the cream is gently heated to 20…21 °C the bulk of the crystals melt, leaving only the hard fat crystals which 8. _____ the
storage period at 20…21 °C, grow larger.
After 1 – 2 hours most of the hard fat 9. _____ crystallized, binding little of the liquid fat. 10. _____ dropping the temperature
now to about 16 °C, the hardest portion of the fat will 11. _____ fixed in crystal form while the rest is liquefied. During the holding
period at 16 °C, fat with a melting point of 16 °C or higher will be added 12. _____ the crystals. The treatment has thus
caused the
high-melting fat to collect in large crystals with little adsorption of the low-melting liquid fat, so that a large proportion of the butter
oil can be pressed out during churning and working.
U n i t S e v e n
CHEESE PRODUCTION
E x e r c i s e O n e
. Read the article below and write one word to fill the gap.
Cheese
Traditionally, cheese 1. _____ made as a way of preserving the nutrient of milk. In a simple definition, cheese is the fresh or
ripened product obtained 2. _____ coagulation and then separation of milk, cream or partly skimmed milk, buttermilk or a mixture
3. _____ these products. It is essentially the product 4. _____ selective concentration of milk. Thousands of varieties of cheeses have
evolved that are characteristic 5. _____ various regions of the world.
E x e r c i s e T w o
. Mark whether the statements below are true or false:
A. Lipases, normally present in raw milk, are activated during pasteurization.
B. Nitrates may all be added to the cheese.
C. The addition of hydrogen peroxide is sometimes used as an alternative treatment for full pasteurization.
D. Homogenization is usually done for most cheese milk.
E. This less severe heat treatment results in a worse final flavor cheese.
F. An alternative heat treatment of 60 °C for 16 sec may also be used.
G. This treatment results in an increase of high initial bacteria counts before storage.
H. Cheese milk must first be clarified, separated and standardized.
Treatment of Milk for Cheese making
Like most dairy products, cheese milk must first be clarified, separated and standardized. The milk may then be subjected to a
sub-pasteurization treatment of 63…65 °C for 15 to 16 sec. This treatment results in a reduction of high initial bacteria counts before
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