United Arab Emirates University
College of Food and Agriculture
Department of Food Science
FDSC458: dairy product technology Lab
Section: 51
Lab #4: Rising film evaporating.
Name ID Number
Hamda Alblooshi 201701818
Due date of experiment: 23/ 2 /2022
Instructor’s Name: Dr. Bhawna Sobti
Spring2022
I. Abstract:
Evaporated milk is the industrial name for sterilized unsweetened condensed milk, i.e., fresh
cows' milk from which a significant part of the water has been removed, it differs from
sweetened condensed milk, which includes introduced sugar. Sweetened condensed milk
requires much less processing to maintain because the added sugar inhibits bacterial growth.
The manufacturing method includes the evaporation of 60% of the water from the milk,
observed through homogenization, canning, and heat-sterilization. The aim is to compare the
quality of fresh milk versus evaporated milk produced by and concentrate by using evaporate.
At the results we analysand that the fresh milk …
II. Introduction:
The first person to maintain milk in concentrated shape was Nicolas Appert who, withinside
the early 19th century, focused milk by boiling it in a water bath over a fire, then poured it
after cooling into glass bottles and sterilized the very last product through heating the bottles
for two h in a boiling water bath. Two innovations made in the second half of the 19th
century resulted, essentially, withinside the procedure this is nevertheless used today. In
1856, Gail Borden patented the evaporation of milk at a decreased pressure, the usage of the
concentrate to make sweetened condensed milk. A technique for sterilizing concentrated milk
in tinned cans which have been turned around in surroundings of pressurized steam,
permitting an exceedingly quick sterilization time, became patented in 1884 by John B
Meyenberg. (Nieuwenhuijse, J. A. 2016).
Evaporated milk is manufactured through a technique of evaporation, concentration,
homogenization, and sterilization of complete milk. The approximate composition of
evaporated low-fat milk is 7.5–9.0% and 18–22% non-fat milk solids. In this procedure, the
complete milk is uncovered to an ultra-high temperature (UHT) procedure after which
packaged aseptically. To prevent contact and response with the metallic in tin cans, a
protecting coating is used. The base material in those cans is steel, however, maximum cans
are tin-plated, or covered with enamel, epoxy, or lacquers to prevent rusting or assault from
the packaged product. Cans used to package milk are sealed by locking the curl on the lids to
the flange on the body of the opened can. Once the seal is accomplished, it is known as a
double seam. Hermetically sealed cans can properly be storing evaporated milk for numerous
months without refrigeration. (Fuquay, J. W.2011)
Rising film evaporators These evaporators function on a "thermo-siphon" principle. Feed
enters at the lowest of the heating tubes and as it heats, vapor starts to form (Fig). The
ascending pressure of this vapor produced throughout boiling reasons the liquid to flow
upwards. At the identical time, vapor manufacturing will increase, and the product is pressed
as a skinny film at the partitions of the tubes.
This co-current upward motion has the useful impact of
making an excessive degree of turbulence withinside the
liquid. This is effective throughout the evaporation of
enormously viscous products. A big temperature distinction is
needed among the heating and boiling aspects of this form of
the evaporator, otherwise, the power of the vapor flow isn't
enough to bring the liquid and to produce the rising film. The
length of the boiling tubes will generally not exceed 7 meters.
This form of the evaporator is frequently used with product
recirculation, where a few the concentrate shaped is
reintroduced again to the feed inlet to produce enough liquid
loading inside the boiling tubes.
Silveira, A. C. P. (2015).
III. Experimental
Materials and Methods:
- Sample collection: Four different animal species specifically goat, sheep, cow, and
Camel, samples have been accumulated with the size of a liter for every raw milk
immediately after milking acquired from different farms in Sebha City, Libya.
complete milk and 3 concentrated milks have been obtained from local supermarkets
made from different foreign companies. All samples have been transferred in properly
labeled, sterile, plastic bottles and saved in a cooler with an ice pack and ultimately
carried immediately to the laboratory and kept frozen at 4.0oC.
- The physicochemical properties: The physicochemical properties of milk samples
have been determined the use of extraordinary American Society for Testing and
Materials, ASTM, together with ASTM D4959-16 for moisture content, D6128-00 for
TSC, D1989-20 for SNF, D2937-00 for density, D974-06 for acidity, D632-12 for
NaCl and D5258-92 for heavy metals, and Lane-Eynon technique for general sugar,
Resr-Gottliebs for fats, pH values have been measured the use of Orion 4 Star, USA.
IV. Results
Quality parameters Fresh milk Evaporated milk
Table (1)
Color yellowish white
shows the different
parameters PH 6.07 7.28 in fresh milk
and Total solid 11.3 25.8% evaporating
milk Moisture content 74.0% 88.7%
V. Discussion
all the milk samples were regarded to have a white color because of the presence of casion,
while the raw milk samples have been having a yellowish color because of the presence of
fat, general solids, kind of animal, and food.
the pH values of all milk samples have been in the variety among 6.07 to 7.28 with a median
of 6.61, pH values had the subsequent order: whole>concentrated> raw milk samples. The
decreased pH values in some studied milk samples might be due to a part of lactose sugar
forming lactic acid bacteria.
primarily based totally on the preparation techniques or hot climate ordinary on the time of
sampling. However, the outcomes confirmed that the share of MC had the subsequent order:
whole>raw>concentrated milk samples.
the percentage of TS of milk samples have been withinside the variety of 11.3-25.8% with an
common of 16.8% On the other hand, the decrease TS probabilities than permissible limits
maybe because of the excessive percent of fats, proteins, sugar and casion. Moreover, the
outcomes confirmed that the share of TS had the following order: concentrated> raw>whole
milk samples.
(Abuaroos, S., Alhmaly, M., Altohami, F., Erhayem, M., Ahmida, K., Aldarmoon, M., &
Mohamed, R. (2018).
VI. References
1. Nieuwenhuijse, J. A. (2016). Concentrated dairy products: Evaporated Milk.
2. Fuquay, J. W., McSweeney, P. L., & Fox, P. F. (2011). Encyclopedia of dairy
sciences. Academic Press.
3. Silveira, A. C. P. (2015). Thermodynamic and hydrodynamic characterization of the
vacuum evaporation process during concentration of dairy products in a falling film
evaporator (Doctoral dissertation, Agrocampus Ouest).
4. Abuaroos, S., Alhmaly, M., Altohami, F., Erhayem, M., Ahmida, K., Aldarmoon, M.,
& Mohamed, R. (2018). Comparative Analysis of Physicochemical Parameters in
Raw and Evaporated Milk from Sebha City, Libya. Journal of Pure & Applied
Sciences, 17(1).
