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 0.1m2 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 inbuilt 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.

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 intrabatch 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.