LUMiSizer Accelerated Physical Stability Analyser

This instrument is an analytical centrifuge used for investigating the physical stability of solutions,

dispersions, gels and foams under accelerated conditions. It is possible to analyse 12 samples

simultaneously under accelerated conditions in the range 0-4000 rpm and 15-45oC. Typical

applications include accelerated creaming and protein sedimentation testing of emulsions and protein

beverages, respectively and also to facilitate a better understanding of the rehydration properties of

high protein food powders.

High-Performance Liquid Chromatography (HPLC)

This Varian HPLC system consists of a tertiary solvent pump, auto-sampler, column oven and UV

detector. The system is normally configured with reversed-phase chromatography columns used for

separation, identification and quantification of proteins and peptides.

Membrane Filtration (polymeric)

This lab-scale membrane filtration plant is built around a Millipore Pellicon 2 filtration system that

consists of a stainless steel holder which can accommodate up to 3 filter elements, each with 0.1

m2 surface area. The unit is used for ultrafiltration and microfiltration of a range of milk-, whey- and

fruit-based feed materials for ingredient development projects. The unit facilitates complete

monitoring and control of flow rates, pressure and temperature, which allows studies requiring

process analytics (e.g., fouling analysis) to be conducted.

Auto-Titrator

This auto-titration unit from Metrohm consists of a computer-controlled, dual burette system with

integrated magnetic and overhead stirrers for acid-base buffering studies of food matrices using

standard pH electrodes. The system also has a conductivity probe and a calcium ion-selective electrode

attached, in addition to a Karl Fischer apparatus for total moisture determination. The unit is also

designed to operate in pH-stat mode for the preparation of protein hydrolysates.

Powder Flow Tester

This recently-developed instrument from Brookfield is based on shear cell technology, which is a

standard approach for characterising the flow behavior of bulk solids. The flow tester is of particular

relevance to researchers investigating powders for food and pharmaceutical applications. Example

analyses include, but are not limited to, flowability, bulk density, compressibility and wall friction. The

ProFlow software package facilitates the rapid estimation of hopper/silo dimensions which are optimal

for a given powder based on data generated during flow testing. A low-volume cell can be used

where sample quantitites are limited, such as studies involving materials which are finite or materials

which are to be exposed to adverse environmental conditions (e.g., high temperature and/or relative

humidity) prior to analysis. Example experiments include measuring the effect of the following factors

on flow properties of a powder: particle size distribution, particle morphology, agglomeration-state,

addition of flow improvers, moisture and fat content.

Viscometer

The HAAKE RotoVisco viscometer from Thermo Scientific is a controlled rate rotational viscometer

which provides viscosity measurements with defined shear rates, flow curves with speed ramps in the

range 0.15 to 1000 min⁻¹, and features fully automatic temperature programs in the range 0 to 100oC.

This instrument consists of a series of measuring geometry cups and rotors and is typically used for

measuring viscosity of samples of oils, creams, milk, whey and fruit based beverages. A method was

also developed on this instrument some years ago for monitoring the hydration of rennet casein

powders.

Mastersizer 3000

This instrument from Malvern is a laser diffraction particle size analyser used for measurement of

particle size distributions of both wet and dry dispersions. It does this by measuring the intensity of

light scattered as a laser beam passes through a dispersed particulate sample. The system is composed

of wet and dry dispersion units, an optical bench, and software that analyses the scattering data to

calculate the particle size distribution of the dispersion. Typical applications include measurement of

fat globule size distribution of food emulsions and particle size distribution of food powders.

KRÜSS Processor Tensiometer K12

The K12 Tensiometer measures surface and interfacial tension (γ) of liquids based on the force acting

on a probe located at the surface/interface. Two types of probes – a Wilhelmy plate or Du Noüy ring

can be used to measure dynamics of surfactant adsorption at the surface/interface and their

effectiveness in decreasing of the γ. A jacketed sample holder connected to a water bath allows

measurements to be performed at controlled temperature. The tensiometer is a useful tool in

assessment of emulsifier functionality for formulation development; it can be also used to study

sedimentation of solutes, wettability of powders or critical micelle concentration of surfactants.

Zetasizer Nano-ZS-HAT

The Zetasizer Nano-ZS uses dynamic light scattering to quickly characterize samples from less than a

nanometer in particle size to several microns (0.3 nm -10 µm). It is particularly suitable for the

characterization of proteins, protein aggregates and nanoparticles using non-invasive backscatter

optics. The system can also measure zeta potential (surface charge) using electrophoretic light

scattering. Zeta potential is a measure of the magnitude of the electrostatic or charge

repulsion/attraction between particles and is critical to stability of solutions. Its measurement brings

detailed insight into the causes of dispersion, aggregation or flocculation, and can be applied to

improve the formulation of dispersions, emulsions and suspensions. The system can be

thermostatically controlled from 0-90oC and requires low sample volumes for measurement. The

system is also equipped with a high temperature (HT) cell which allows measurements to be taken at

up to 120oC and has an in-line auto-titrator which facilitates the study of pH and ionic conditions on

size and charge of proteins.

Mini-Electrophoresis System

Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) separates proteins primarily by

mass and several forms exist including native, non-reducing and reducing PAGE which can provide

different types of information about the protein(s). Once separated by electrophoresis, proteins can

be detected in a gel with various stains and/or excised and extracted for analysis by mass

spectrometry. Mini-electrophoresis systems and their precast gels are more convenient, consistent,

safer and faster to run compared to traditional poured gels. Mini gels require less time and reagents

than their larger counterparts and are suited for rapid screening of samples. This system is commonly

used to determine protein profile of a sample and to monitor protein denaturation/aggregation in

response to different compositional (e.g., enzymatic activity) or processing conditions (e.g., thermal

processing).

Rheometer

This AR-G2 rheometer is used to study the flow and deformation of a sample. The measuring system

consists of a stator (peltier plate or peltier concentric cylinder) and a geometry (cone, plate, parallel

plate or concentric cylinders). Rheological tests on simple and complex fluids like milk, yogurt,

emulsions and semi-solid products like cheese and protein gels can be performed. Flow experiments

can be performed to determine the viscosity data of fluid materials and to simulate a process shear

rate. Oscillatory experiments can be used to have information on structure, time dependency, and

temperature stability/dependency. Moreover, creep experiments can be run to have information on

structure, long time processes, storage stability, and phase separation. The unit is also equipped with

a starch pasting cell which is often used to generate real-time viscosity data during simulated high

temperature-short time thermal processing of protein solutions.

Inopor® inoMini Cross Flow Filtration Unit

This is a pilot scale membrane filtration plant designed to facilitate small-scale membrane

filtration experiments using microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF)

membranes. The typical feed batch size is <10 litres and the unit can be operated in a batch

recirculation or feed-and-bleed configuration. The maximum operating pressure is 50 bar,

generated using a low-pulsation, high pressure piston pump, allowing NF filtration to be

achieved. The unit is flexible and modular, designed specifically to accommodate either

ceramic (single tube) or polymeric (flat sheet) membranes for test purposes and incorporates

a by-pass loop for control of feed flowrate across the membrane elements. The unit has in-

built temperature control and rotameters for retentate and permeate flowrate

determination. Examples of its applications within the group include casein and whey protein

fractionation in skim milk using MF membranes, whey protein concentration in liquid whey

using UF membranes and polyphenol enrichment from clarified fruit puree using NF

membranes.

Fouling Rig

The fouling rig is a benchtop-scale tubular heat exchanger (THE), with associated control and

monitoring facilities that was built to study the fouling behaviour of milk and other liquid food systems

prone to fouling. It includes a feed vessel, THE , a positive displacement progressive cavity pump, with

high temperature food-grade silicone rubber stator, to control the liquid flow through the THE, two

electronic pressure transducers (Keller-druck, Winterthur, Switzerland) located before and after the

THE to measure the temperature change and pressure drop resulting from fouling combined

refrigerated and heating bath circulator for supplying the THE (Grant, LT ecocoolTM100, Cambridge,

UK), thermocouples (Digitron 2024T Digital Thermometer Pt100, Port Talbot, UK), an analogue

pressure gauge and flow throttling valve to control pressure. The inlet temperature of the solution in

the feed vessel is maintained at 30°C using the water bath and the temperature is adjusted to the

desired target temperature on starting the experiment. The temperature of the hot water, inlet and

outlet solutions are monitored by the thermocouples and pressure transducers.

Buchi Spray Dryer

(B-191, BÜCHI Labortechnik AG, Flawil, Switzerland) with a maximum evaporation capacity of 1.5 L H2O

h-1 allows production of powders on a lab scale ranging from 50 mL to 2000 L. Details of the design are

depicted in the figure below:

Schematic diagram showing the set-up and the principle of operation for the laboratory-scale BÜCHI

B-191 spray drier. The inlet temperature is regulated directly by the power of the heater (3) and the

outlet temperature (measured at 8) is regulated indirectly by controlling the feed flow rate (2) and the

air flow (1). Feed is introduced into the main drying chamber (4) by a 2-fluid nozzle atomiser, where it

is rapidly dried by heated air; dried particles are pulled into the cyclone (9) by means of an aspirator

(12). Large and heavy particles (i.e., wet lumps and scorched particles, falling off the build-up around

the nozzle and around hot air inlets, respectively) are separated from the powder by means of the air

pull and gravity (5 and 6, respectively). By design, air pull is insufficient to move larger and heavier

particles into the cyclone, making them fall into the waste collection container (7) at the bottom of the

dryer main chamber. Dried powder particles are further separated from air in the cyclone and the final

powder is collected in the powder collection container (10) at the bottom of the cyclone. The clarified

air is exhausted at the top of bag filter (11). Source: Drapala, et al., (2017). Influence of emulsifier type

on the spray-drying properties of model infant formula emulsions. Food Hydrocolloids, 69, 56-66.

YTRON ZC and ZHV Instrument

This hybrid instrument was custom-fabricated for the Food Ingredients Research Group to

incorporate the proven existing elements of powder induction (ZC) and in-line mixing (HV)

capability from YTRON. In ZC mode, the unit is a very effective in educting and incorporating

powders into the recirculating liquid while in HV (i.e., high velocity) mode the unit is very

effective at dispersing, homogenising and wet milling of particles/droplets in solution. The

unit is combined with a positive displacement progressive cavity pump and in-line tubular heat

exchanger for control of recirculating liquid flowrate and temperature, respectively. The

operational variables which can be studied include rotor tip speed, residence time, back

pressure and temperature. Examples of applications include induction of high protein dairy

powders into water and emulsification of oils into protein-containing concentrate streams for

in-line emulsion preparation in the absence of a homogeniser.

BARDS

Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS) is a platform technology

based on an acoustic phenomenon (commonly called the hot-chocolate effect) observed

when you add a compound to a solvent. The dissolved compound releases gas into the solvent,

which in turn changes the compressibility of the solvent. This results in a reproducible

outgassing of the solvent and slows down the speed of sound, induced by a magnetic stirring

bar, through the solvent. The BARDS analytical approach finds applications in both food and

pharmaceutical sectors including screening raw materials, quality control, inter and intra-

batch analysis, blend uniformity analysis and detection of counterfeiting. In the Food

Ingredients Research group, we use the BARDS instrument for studying the rehydration

properties of various ingredient powders, in combination with other complementary

analytical approaches.

Silverson High-shear Mixer

The high shear mixer offers great versatility by allowing to perform a wide range of mixing operation

including emulsifying, homogenizing, disintegrating, dissolving, dispersing, blending, particle size

reduction and de-agglomeration thanks to the interchangeable work heads.

Microscopy

The Food Ingredients Research Group does not have internal microscopy facilities and works

closely with the Biosciences Imaging Centre at UCC and the National Food Imaging Centre at

Teagasc Food Research Centre, Moorepark. The facilities most commonly used are (1)

scanning electron microscopy (SEM), (2) confocal laser scanning microscopy (CLSM), (3)

transmission electron microscopy (TEM) and (4) atomic force microscopy (AFM). Individual

researchers in the group are trained on use of each of these microscopy facilities, with training

plans developed to suit the project needs.

Links to these facilities can be found here:

https://www.ucc.ie/en/anatomy/bsic/

https://www.teagasc.ie/food/food-chemistry--technology/national-food-imaging-centre/

Brookfield Rheometer RST-CC TouchTM

This instrument is used to measure the deformation of a liquid samples to shear stress (i.e.,

flow). The geometry used for this unit is a cop and bob with a jacketed sample vessel to allow

control of the sample environment during the analysis. In contrast to other rheometers used

by the group, the RST unit does not require a supply line of compressed air as the rotation of

the spindle is controlled by the electrical current. This feature of the instrument allows its

portability and measurement of rheological properties of liquid samples where it would not

be possible when using a traditional rheometer. Therefore, this instrument is frequently used

in commercial trials, where it can be transported to a factory to perform on-site analysis of

samples collected directly from the production lines.