Avda. da fábrica da Luz S/n.
Tfno 34 982 252231 (ext.21307)
Fax 34 982 251611
TECHNICAL RESSOURCES OF THE
CENTRO TECNOLÓXICO LÁCTEO DE
The pilot plant of dairy industries is located in the ground floor of the building
of the Centro Tecnolóxico Lácteo de Galicia. It takes up an area of 575 m2
that are distributed in the following way:
Production area = 350 m2.
Laboratories = 50 m2.
Management area = 12 m2.
Engine room = 46 m2.
Changing rooms and toilets = 24 m2.
Approaches and corridors = 93 m2.
The facilities and technical means the pilot plant has, allow to reproduce, at a
small scale, the most representative processes of the Dairy Industry.
Raw milk reception, milk thermization and standardization, both in fat
content and in proteins and dry matter.
Milk and dairy products pasteurization and homogenization.
o Fresh pastes.
o Soft pastes.
o Pressed pastes.
o Cooked pressed pastes.
o Processed cheese
Fermented milk production:
o Firm, stirred and liquid yoghurts.
o Other fermented milks.
UHT dairy products production.
o Liquid products.
o Semi-solid products (Desserts).
Implementation of selective filtration processes in tangential flow,
either in the dairy products preparation or in the coproducts
Generally, any unit operation or process that needs the technical means that
are detailed next.
2 FACILITIES DESCRIPTION
2.1 RECEPTION AND PRETREATMENTS AREA
In this area, milk unloading process is carried out. From a tank, we can
receive a maximum of 2,000 L. Once the milk is in our facilities, this area
allows us to carry out the thermization, clarification and standardization of fat
content in the manufacture milk. Normalized milk can be sent to other
processing areas, where ingredients and additives can be incorporated,
and/or it can be pasteurized - homogenized.
This room is fitted with the following equipment:
1 Isothermal reception tank of 2,000 L with agitator.
2 Isothermal storage tanks of 1,000 L with agitator.
1 Plate heat exchanger (Thermizer) with variable flow: 500 – 1,000
Centrifugal separator of 1,000 L/h. (connected to the thermizer at the
2 Refrigeration tanks with a
capacity of 250 L, with a system
for incorporating ingredients.
1 Plate heat exchanger
(Pasteurizer) with variable flow:
500 - 1.000 L/h, equipped with two
maintenance sections with
Two-stage homogenizer with a flow
of 500 L/h. Maximum pressure:
300 bar (connected to the
pasteurizer at the ascending
Control panel for automation
system by remote control of the
reception, pre-treatment and CIP operations.
ALMIX equipment for ingredients incorporation and mixing, fitted with
hoppers for solids incorporation, systems of agitation and mixing with
regulation of speed, system of direct or indirect heating and indirect
cooling, vacuum pump and mixing tank of 140 litres.
CIP area (Cleaning in place)
o Tank of 500 L of recovery water.
o Tank of 500 L of one-step cleaning product, with a system for
heating the cleaning product and a system for the adjustment
and automatic dosage of the detergent.
o Tank of 500 L of osmotized water for specific uses.
o Connection to mains water for final rinse.
2.2 CHEESE-MAKING AREA
In this area the operations of transformation of milk in cheese can be
carried out, either from raw milk or previously pasteurized and standardized
milk in the pretreatments area. Different cheese productions can be carried
out: fresh pastes, soft pastes, pressed pastes and cooked pressed pastes.
There are 2 processing lines, a manual one and an automated one.
The equipment we have is the following:
Static cheese brine of 1 level of 3,000 litres, automatic temperature
control by internal coil.
Diatomaceous earths filter for the rejuvenation of the brine.
Automatic moulds washing machine, with a system for heating the
detergent solution by steam injection and recirculation of the cleaning
Drying, ripening and refrigeration chambers with temperature and
relative humidity control.
Discontinuous butter churn for manufacturing butter.
“Traditional process” line
o Open Dutch-type cheese vat with
a capacity of 200 L.
o Horizontal pneumatic press with
“Industrial process ” line
o Close Closed Double O cheese vat
with a capacity of 500 L.
o Moulds filling column with a
prepressing system, automatic
curd dosing and a mechanism for
regulating the height of the curd
o Tunnel press, for microperforated
moulds with programmable
2.3 TANGENTIAL FILTRATION AREA
The filtration technologies are not grouped together in one room. There
is the necessary equipment to carry out the 4 filtration techniques:
reverse osmosis (RO)
These technologies allow us to carry out:
microbiological purification of dairy fluids (milk, whey and cheese
brine) using MF
fractionation of whey proteins using UF
dairy fluids concentration (whey, milk, filtrate) using RO
dairy fluids (milk and whey) concentration and demineralization
draining of whey from latic pastes using UF
milk concentration for cheese-making (protein standardization or MMV
The equipments are:
Tangential microfiltration equipment “Bactocatch” system with multi-
channel cartridge mineral membranes. Membrane surface: 0.24m2.
Ultrafiltration equipment with multi-channel cartridge mineral
membranes. Membrane surface: 1.2 m2 (possibility of choosing the
membrane pore size, 20nm, 50 nm and 100nm are available).
Mixed ultrafiltration equipment, of organic membranes in plate-and-
frame or multi-channel cartridge mineral membranes.
Versatile filtration equipment with organic membranes in spiral-wound
system. Its design and construction allow to carry out filtration
operations in the range of 100nm to 0.001 nm, this is to say UF, NF
and RO. It uses membrane modules with 3838 sizes.
2.4 FERMENTED MILK MANUFACTURE AREA
In this department we have all the equipment necessary for the
production of fermented milks. From additivated, pasteurized/homogenized
milk we can carry out the process of obtaining:
solid products (in-package fermentation)
semisolids (tank fermentation and subsequent packaging)
liquids (tank fermentation and subsequent mechanical treatment
We have the following equipment:
1 lacto-fermentation tank with a capacity of 150L, equipped with
agitation system with adjustable speed control, jacket, steam
heating system and water and ice water cooling system.
1 lacto-fermentation tank with a capacity of 250L equipped with
steam heating system, mains water cooling system, and
Automatic rotary filling machine in ultraclean conditions with
laminar flow cabin for dairy fluid products even with particles, in
pre-formed little cups of 125 mL and thermosealed aluminium lid.
2.5 MINI-CHEESE FACTORY AREA
This laboratory has the necessary equipment for manufacturing dairy
products, mainly cheeses, at a laboratory scale.
Thermomix: Equipment with a capacity of 2 litres that allows to carry
out simultaneous or independent operations of discontinuous thermal
treatment, reincorporation of powdered products, chopping and
4 open Dutch-type cheese vats of 10 L.
4 press-heaters with temperature control and variable pressure. Two
Centrifugal separator of 100 L/h.
Homogenizer that allows the treatment both of liquid and solid
products (lactic curds). Capacity of 50-100 L/h.
Double stage homogenizer APV-2000 for high pressure operation (0 -
2000 bar) that allows the treatment of both liquid and solid products
(dairy curds). Capacity of 11 L/h.
Pneumatically-operated manual thermosealer for plastic containers. It
is equipped with a regulator of the temperature of the resistors, of the
duration of the sealing process and of the pressure exercised.
Polyvalent STEPHAN machine for the development of processed
cheeses (melted), sauces, baby-foods etc. Capacity of the bowl = 2.5
L, maximum temperature = 95ºC.
2.6 BAKERY PRODUCTS AREA
Kneading-mixing machine with 2 independent bowls for 15 kg of dough
in the kneader and 35 L in the mixer.
Double oven for 18 cans with fermentation chamber.
2.7 STERILE PRODUCTS AREA
We have an installation that allows the thermal treatment at ultra-high
temperature (UHT) and the subsequent aseptic packing of liquid dairy
products with a moderate viscosity. The equipments design allows to carry
out an indirect or direct thermal treatment using steam injection, the
versatility of the facilities includes very large temperature cycles and applied
times, the homogenization can be done before or after the thermal
As for the packing there are two possibilities:
Hygienic packing in laminar flow cabin, using auto-hammered glass
Aseptic packing in tetra-slim of 200ml and packing in cardboard box of 24
These operations can be carried out due to the following equipment:
Pilot plant for thermal treatment TETRA THERM ASEPTIC PILOT 300T:
o Nominal flow 300L/h, (with homogenizer 225 L/h).
o Indirect heating by means of a flat tubular exchanger.
o Direct heating by means of steam injection with expansion
o Two-stage pilot homogenizer, Tetra Alex S05.
o Laminar flow hood for hygienic samples collection: Tetra Alcab.
"Tetra aldose" aseptic dosing unit. This technology allows to dose in
the aseptic production lines those liquids whose high thermal
sensitivity would make it difficult to resist the traditional sterilization
Aseptic tank for storing fluids prior to their aseptic canning. Capacity of
Aseptic filling machine TETRA BRIK ASEPTIC 9 (TBA-9) packing with
multi-layer paper in "slim" format of 200 ml. Packing capacity = 4500
packs / hour.
Tetra CARDBOARD PACKER 50, packing in cardboard box of 8 x 3
2.8 PROCESS CONTROL AREA
The laboratory of the pilot plant is equipped with:
pH meter and acidimeter.
Gerber equipment for determining the percentage of fat in dairy
Heater for determining the Dry matter.
Milkoscan (FOSS electric).
Precision scales with infrared lamp for rapid desiccation of samples.
2.9 ENGINE ROOM
In this area, there is all the equipment destined to produce the auxiliary
fluids necessary for the working of the equipments of the manufacturing
areas: steam, quality water, ice water and compressed air.
Pirotubular, horizontal, automatic boiler for producing 200 kg/h of
Equipment to produce ice water with a well of 5,000 L and cooling
Compact equipment of reverse osmosis for producing quality water.
Flow of 3 m3 /h and storage in a polyester tank.
2 compressors for producing compressed air refrigeration dryer.
3 FACILITIES DESCRIPTION
3.1 MICROBIOLOGY LABORATORY
In this laboratory diverse microbiological analysis are carried out: total
and fecal coliforms, Staphylococcus aureus, Listeria spp., Salmonella spp.,
moulds and yeasts, total count of microorganisms in dairy products and in all
kinds of food products.
It is formed, among others, of the following equipments:
Laminar flux cabin, in order to ensure the sterilization of the working
Autoclave, to sterilize both the material and the culture mediums.
Diverse heaters at different temperatures to carry out the incubations.
Masticator, to homogenize the samples.
3.2 LABORATORY OF PHYSICOCHEMICAL ANALYSIS
In this laboratory the analysis of fat, dry matter, pH and proteins of
diverse dairy products, as well as the milk content in lactose, lactulose and
calcium, are carried out.
The available equipments are:
2050 Soxtec Avanti Auomatic System: It carries out the extraction of
the fat of the dairy products by means of a completely automatic
system in which the extraction of the solvent in the extraction unit is
carried out in two stages.
Kjeltec System 1002 Distilling Unit: This device is used for the
determination of protein in the dairy products according to the Kjeldahl
Method. It allows to do macro distillations by steam dragging rapidly.
Digestor System 6 1007: It allows the digestion of the sample to then
proceed to the distillation process.
Centrifuge, Heraeus Sepatech Labofuge: It has capacity for 16
samples and reaches 5000 r.p.m.
Muffle: It is used for the total calcination of samples since it can reach
temperatures up to 1200ºC.
3.3 INSTRUMENTAL LABORATORY
In this laboratory different components of food products are analyzed by
means of computer-supported analysis devices.
Among other devices:
H.P.L.C (High performance liquid-chromatography): It is used for the
determination of cheese-making whey in powdered milk.
NIR: With this device we can analyze the majority components of
different types of samples without any previous treatment, by means
of the light transmitted through the sample or the light reflected by its
3.4 SENSORY ANALYSIS ROOM
Since October, 1993, the Centro Tecnolóxico Lácteo de Galicia has a
tasting panel specialized in the sensory evaluation of dairy products. Thanks
to this panel it can offer solutions to situations such as:
Determination of the sensory differences between a product and its
Determination of the sensory incidence of the use of new ingredients
and different technologies.
Accomplishment and comparison of the sensory profiles of one or
3.5 PHYSICAL PROPERTIES ANALYSIS LABORATORY (APF)
Since September, 2005, the Centro Tecnolóxico Lácteo de Galicia has
had a Research area devoted to the Study of Physical Properties. The work
field includes any type of material and tries to give support to the industrial
and even university areas which need to know and to improve their products
to a greater extent.
Stress controlled Rheometer AR-G2:
Rheometry is the technique which provides viscosity values and
elastic and viscous modules of the torque by means of magnetic
bearings substituting the classic air bearing, it provides microeffort
capacities. It is ideal for liquid samples with very low viscosity. The
mechanical properties of liquids and semisolids are very interesting
for different industrial sectors as those devoted to the manufacture
of paint, varnishes, coverings, polymers, cosmetic products,
pharmaceutical products, food, petroleum or derivative materials...
Texture analyzer. TA.XT. Plus:
Rheology is a science which studies the mechanical response of the
materials in general. Nevertheless, when we want our tests to
resemble the real world as much as possible, a textures analyzer is
used. A textures analyzer subjects the material to different efforts,
deformations and deformation speeds and it allows, from the
measures carried out, to obtain parameters like Hardness, Fragility,
Fracturability, Stickability, Chewability, Gumminess, Resilience,
Elasticity, Bloom Resistance, etc on an extensive range of products
among which stand out food, pharmaceutical, adhesive, cosmetic
The Optigraph coagulometer is a system (equipment and software)
which allows to characterize the capacity of milk to coagulate by
using optical measures in the region of the near-infrared. This
equipment can calculate in real time all the parameters needed for
processing cheese: coagulation time, firmness of the curd, speed of
aggregation... These parameters are obtained thanks to the optical
information acquired in real time...
Brookfield DV-II + viscometer.
It is an optical instrument that characterizes concentrated
emulsions and dispersions. This experimental equipment can
provide different magnitudes, such as: transmitted and reflected
light, particles migration speed, volume fraction (concentration) in
the flotation layer, evolution of the average diameter of particle
according to time, etc. All these magnitudes are therefore used to
characterize dispersions, suspensions or emulsions and to obtain
MASTERSIZER 2000 by MALVERN INSTRUMENTS:
This is an instrument for measuring the size of particles. It can
characterize the above mentioned sizes in a range from 0.02
micrometers up to 2000 micrometers. It uses laser diffraction
technology and can measure both liquid and powdered samples.
Most of the properties of dispersions, emulsions or suspensions are
related to the particle size of the dispersed phase, so it is
fundamental to have the capacity to obtain this information.
MDSC (MODULATED DIFERENTIAL SCANNING CALORIMETER)
Q1000 by TA Instruments:
This equipment is a differential scanning calorimeter with heat flow
technology. It measures endothermic or exothermic transitions or
changes of calorific capacity. Therefore it can obtain information
about crystallizations, fusions, denaturalizations, vitreous
transitions, gelatinizations as well as Cp absolute values. It has
devices capable of scanning in temperatures from -90ºC up to
600ºC. It also has an automatic sampler with 50 positions and 5
references which allows to work in great comfort.
The colorimetric equipment we have is a ColorFlex
spectrocolorimeter by Hunterlab. It is used to measure the colour of
both liquid and solid samples. The software can represent the
different scales of colour and it can use different illuminants. It has
3 different models, 45º/0º, diffuse/8º (sphere) and diffuse VSAV
(very small area of vision). Given its versatility, it is possible to
realize measurements of foods, paints, textiles...