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Name of Method Equipment (sample holder, temperature/frequency range, etc.) Contact person first name Contact person last name Institution Country
AFM - Imaging of cell wall polysaccharides

A water solution containing the polysaccharides fractions in a concentration of approximately 10 µm/ml must be dropped onto freshly cleaved mica. Then, the specimens should be vacuum-dried at 30 °C for two hours and kept in a desiccator prior to AFM observations. In AFM, chose the mode of scanning (Contact, Tapping or similar with care of appropriate AFM tip). Chose image scan 2x2 micrometers and scanning resolution better than 512 x 512 lines.

Artur Zdunek Institute of Agrophysics PAS Poland
AFM - nanomechanics
  1. Fix a sample on stiff support. Fixation method is individual for a type of sample and experiment.
  2. Run you AFM and prepare to force-volume mode.
  3. Chose cantilever to your sample. General rule is softer sample>>softer cantilever. Generally it must be find experimentally.
  4. Calibrate the cantilever spring constant k (N/m) in air. For calibration, thermal tune is most often used. The resonance frequency ω from the thermal tune put to the equation k/kn = ω2/ωn2, where kn and  are nominal spring constant and nominal resonance frequency ωn. It should be done in several replicates.
  5. Calibrate a deflection sensitivity of the cantilever in the same media as for experiment. Calibration may be done on glass and is expressed in nm/V. It should be done in several replicates.
  6. Go with cantilever above the sample and approach.
  7. Capture the force curves. It may be done in a matrix to have a force map of the sample.
  8. Fit the Hertz-Sneddon model  (equation below) to experimental force-indentation to determine the Young’s modulus E. F – force, d - indentation, a - the tip opening angle, n - the Poisson ratio

                              

Artur Zdunek Institute of Agrophysics PAS Poland
Hardness measurement

The universal testing machine Instron 4465 (Instron Ltd., High Wycombe, UK) equipped with a loading cell (100 N).Three-point bending with a flat rectangular-shaped aluminium probe (3 mm × 29 mm) is used. Samples are positioned perpendicularly over a sample holder (distance between two holding points is 12 mm). Extrudates are pressed with an aluminium probe with a constant rate of 5 mm/min and the force resisting the movement is recorded.

Kirsi Jouppila University of Helsinki Finland
Emulsion, particle size, stability

homogenization

Dominik Guggisberg Agroscope Switzerland
Mixolab measurements, Mixolab “Chopin+” protocol (ICC 173, ICC Standards 2008);

Required amount of flour for analysis was calculated by Mixolab software according to input values of flour mixtures moisture as well as water absorption.

The measurements are commonly performed using the standard Mixolab ‘Chopin+’protocol (ICC No. 173) or modified Mixolab ‘Chopin+’protocol.

Modificaton of standard mixolab protocol could consist in dough weight change from 75 g to 90 g because of the specific nature of the system such as gluten-free systems:

Miroslav Hadnađev Institute of Food Technology Serbia
Frequency sweeps test

- HAAKE Mars rheometer (Thermo Scientific, Karlsruhe, Germany).

  - parallel plate measuring geometry

- The plates were serrated in order to prevent the sample slippage.

- A sample was placed on the lower plate, and the upper plate was lowered until the gap of 1.0 mm was reached. The excess of sample was trimmed and the edges were sealed with a paraffin oil to prevent the sample from drying during measurements. The sample was left to rest for 10 min before measurements, so that residual stresses could relax. All experiments were performed at 30 °C in triplicates. Frequency sweeps test was carried out from 0.1 to 50 Hz, under a 5-Pa strain level, which was within a linear viscoelastic region of all tested samples.

Miroslav Hadnađev Institute of Food Technology Serbia
Creep and Recovery Measurements

- Haake Mars rheometer (Thermo Scientific, Germany) equipped with PP35 S serrated parallel plate measuring geometry (35-mm diameter, 1-mm gap) in order to prevent sample slippage

-  excess of the sample at the plate edges was neatly trimmed and the edges sealed with a paraffin oil to prevent the sample from drying during measurements.

- The sample was left to rest for 10 min so that residual stresses could relax. Measurements were performed at 30±0.1 °C.

- Creep was recorded at a shear stress of 7 Pa, which was within the linear viscoelasticity region for 300 s, followed by a recovery phase of 900 s at a stress of 0 Pa.

Miroslav Hadnađev Institute of Food Technology Serbia
Digital image analysis

The images were acquired by default settings for brightness and contrast, saved in tiff format and cropped using ImageJ software (National Institutes Health, Bethesda, MD) to obtain the largest possible field of view representing 40× 50 mm of the slice area.

Cropped colour images were converted into an 8-bit greyscale images, whilst the threshold method used for differentiating gas cells and non-cells was carried out by means of the Otsu algorithm.

Miroslav Hadnađev Institute of Food Technology Serbia
Map of volatile composition using electronic nose

The electronic nose system FOX 4000 combined with HS100 autosampler together with α Soft version 8.0 software for data processing (Alpha M.O.S., Toulouse, France) was used to study the headspace of jam samples. The system composed of an array of 18 metal oxides sensors (MOS) placed in three controlled temperature chambers. Two grams of jam sample was placed in a 10-mL vial that was hermetically capped with a polytetrafluoroethylene/silicone septum and incubated for 600 s at 80C under agitation (500 rpm) for headspace generation. Synthetic air and nitrogen were used as carrier gas with a flow rate of 150 mL/min. A volume of 1,500 L was injected at an acquisition time of 120 s. 

Denisa Duta National Institute of Research&Development for Food Bioresources IBA Bucharest Romania
Nuclear magnetic relaxation

Bruker AVANCE III solid state spectrometer (300MHz)

Cristina Silva Escola Superior de Biotecnologia Portugal
Water activity determination

Measurements were performed with a dew point hygrometer (Aqualab - Series 3, Decagon Devices Inc., USA.). The sensitivity of the equipment was 0.001. Calibration was carried out before experiments with distilled water and saturated saline solutions.

Cristina Silva Escola Superior de Biotecnologia Portugal
High pressure homogenisation Antonio Vicente University of Minho Portugal
Thermal denaturation + Aggregation Antonio Vicente University of Minho Portugal
Layer-by-Layer Antonio Vicente University of Minho Portugal
Oil distribution in spray-dried o/w emulsions by solvent extraction

Surface free oil: powder sample poored on a filter. Washing with hexane. Solvent recovery, evaporation, and weigning of extracted surface free oil.

Surface accessible oil: powder sample recovered after surface free oil extraction. Left in hexane for 48h and filtered for solvent recovery, evaporation and weighing of extracted surface accessible oil 

Total oil: reconstitution of liquid emulsion dissolving 1g of powder in 1.2 g water. Solvent extraction using hexane/isopropanol mixture. Phases separation by centrifugation. Evaporation of solvent and weighing of total oil extracted.

Christelle TURCHIULI AgroParisTech France
Determination of peak viscosity using fundamental rhelogical equipment

The flour suspension for fundamental rheological tests was prepared with 12.4 g (calculated on 14 % moisture basis) of flour and 70 ml of distilled water in order to obtain the same flour–water ratio as in the standard Amylograph method. Fundamental rheometric measurements were taken using the HAAKE MARS—Modular Advanced Rheometer Systems (Thermo Scientific, Germany). The measuring geometry consisted of measuring cup Z40 (43.4 mm diameter, 8 mm gap) and FL2B paddle-shaped rotor with 2 blades. In order to prevent moisture evaporation from the sample, the solvent trap Z40 DIN was used. Two methods for determination of pasting properties of wheat flour were developed: so-called slow and rapid procedure. Slow procedure comprised the complete simulation of Amylograph test with a heating rate of 1.5 C min-1 from 30 to 95 C and maintaining the temperature of 95 C for a period of 600 s. A shear rate of 10 s-1 was applied, which corresponded to 95 rpm. The rapid procedure comprised the tempering of flour suspension at 50 C for 180 s, heating from 50 to 95 C at a heating rate of 3 C min-1 and subsequent maintenance of temperature of 95 C for 300 s to ensure starch gelatinization. Three parameters were recorded in duplicate: pasting temperature, peak viscosity and peak temperature.

Miroslav Hadnađev Institute of Food Technology Serbia
Polarised light microscopy

One drop of the sample was placed in the middle of a glass slide and a glass cover slip was centered above the drop.The temperature can be controlled by using a temperature controlled stage.

Sonia Calligaris University of Udine Italy
Preparation and Analysis of Edible Oil Oleogels Emin YILMAZ Emin YILMAZ Çanakkale Onsekiz Mart University Turkey
Thermal profile determination

Differential scanning calorimetry (DSC)

Cristina Silva Escola Superior de Biotecnologia - UCP Portugal
Surface tension

Easydyn K20

Krüss GmbH, Wissenschaftliche Laborgeräte
Borsteler Chaussee 85‑99a
22453 HAMBURG, Germany

http://www.kruss.de/

 

Gerhard Schleining BOKU Austria