Speakers – June 2, 2022 – Concurrent 4C
Synchrotron Soft and hard X-rays, SAXS
Dr. Jian Wang – Canadian Light Source, University of Saskatchewan
Dr. Jian Wang is a Senior Scientist, Beamline Responsible of the Spectromicroscopy (SM) Beamline of the Canadian Light Source (CLS), and an Adjunct Professor of Chemistry with the University of Saskatchewan. He received his Ph.D. in Physical Chemistry from McMaster University in 2008. After the postdoctoral work resident in the Advanced Light Source, USA, he joined CLS in 2009. He worked as the SM Beamline Research Associate or Acting Beamline Scientist until 2015 when he was promoted to the Beamline Responsible Scientist, and became a Senior Scientist in 2021. His current research interests include materials analysis on environmental and energy science, and instrumentation developments for STXM, Ptychography, and X-PEEM, with over 180 peer-reviewed publications.
Application of soft X-ray spectroscopy and microscopy for food science research
Dr. Gosia Korbas – Canadian Light Source
I’m a senior scientist in the Science Division of Canada’s only synchrotron – Canadian Light Source. I’m responsible for commissioning and operation of the BioXAS-Imaging beamline, which is dedicated to hard X-ray fluorescence imaging. We use this technique to reveal distribution of elements (essential or toxic) in various biological and environmental specimens. You can read more about this technique and BioXAS-Imaging beamline in my Work section.
My favourite element is mercury (Hg) and I’ve been using synchrotron techniques to study its speciation and distribution in creatures as small as zebrafish larvae and as big as whales.
I’m especially interested in Hg accumulation in sensory organs and detrimental effects associated with its accumulation.
I’m passionate about STEM education and love working with various school groups coming to Canadian Light Source through Students on the Beamlines (SotB) program. You can read more about this innovative program here or head to my Work section for more details on my work for SotB as a science mentor.
If there is anything here that has sparked your interest or if you would just like to say hi, I would love to hear from you!
Application of hard X-ray spectroscopy and microscopy for food science research
Dr. Adam Leontowich – Canadian Light Source
Adam received a B.Sc degree in Chemistry from the University of Saskatchewan in 2008. In the summers, he worked in the labs of Prof. Matthew Paige and Prof. Robert Scott, synthesizing and characterizing nanoparticles and ligands for catalysis.
During this period, Adam attended the Canadian Synchrotron Summer School at CLS and had an influential chat with Prof. Adam Hitchcock, a pioneer of soft X-ray microscopy. Adam then moved to Hamilton, Ontario to pursue a Ph.D in Chemistry at McMaster University, applying the scanning transmission X-ray microscope (STXM) for a new purpose: patterning and lithography at the sub-50 nm scale.
Upon defending his thesis in 2012, he accepted a post-doctorate position in the X-ray Optics for Extreme Conditions group lead by Dr. Sasa Bajt, at DESY, Hamburg, Germany. There he fabricated multilayer structures, including multilayer Laue lenses for hard X-ray microscopes, and reflective coatings for EUV and soft X-rays.
In 2013 Adam returned to CLS and has been there ever since. First he led the design, construction and commissioning of a new cryo-STXM for the SM beamline. Then in 2016 he was convinced by Dr. Ariel Gomez to take the jump into reciprocal space and join the Brockhouse Sector, an empty patch of concrete floor that would soon become three hard X-ray beamlines. Adam continues to develop and deliver the many endstations at BXDS, including the powder diffraction and SAXS/WAXS user programs, and is interested in the fate of nanoparticles in wildlife and the environment.
Diffraction, SAXS, WAXS techniques
Dr. Fernanda Peyronel, Senior Technical Associate – University of Guelph
Dr. Fernanda Peyronel is a world expert in the technique of Ultra Small Angle X-Ray Scattering (USAXS), based at the University of Guelph in the Food Science Department. She uses the USAXS technique to study food structures at the nano- and micro- level. Her latest research focuses on chocolate structures, with a special emphasis on chocolate aromas. Her short course, offered at the University of Guelph, covers all the steps require to process the cacao bean into a chocolate bar. She is further concerned with the waste product from chocolate making, and is looking for application of the cacao bean shells in her research. Dr. Peyronel has guided Food Science graduate students through their research, by helping them carry out projects as well as teaching them how to use different techniques within the Department of Food Science her advanced knowledge of USAXS.
SAXS, WAXS applications for food sciences research
Small-Angle X-Ray Scattering (SAXS) and Wide-Angle X-Ray Scattering (WAXS) are well-established techniques with sound theoretical background. X-rays can easily penetrate matter due to their high energy and short wavelength. The scattered radiation allows the investigation of the internal structure of crystalline materials.
The atomistic structure of materials is revealed in the WAXS region. The q-position of the detected Bragg peaks paired up with the Unit cell model allows the identification of materials based on atomic coordinates. Here q is used to indicate the scattering vector magnitud, the “stick” used to measure in reciprocal space and with units of inverse length. The SAXS region is where information regarding molecules is obtained, with the Bragg peak q-position in this region giving information regarding the arrangement of the molecules.
When characterizing materials using SAXS or WAXS, one can use bench-top instruments or synchrotron facilities. The latter offers better resolution based on the higher flux of photons and the possibility of manipulating many parameters that are generally fixed when using bench-top instruments. Another advantage of synchrotron facilities is that they have the space and resources to use detectors that are hard to implement in a bench-top instrument or that are too expensive.
Food scientists have successfully elucidated the structure of many crystalline edible fats. Understanding the polymorph in which an edible fat crystallizes is crucial for its application. A good margarine is valuable when it is in the β’ polymorph, like what is desired in shortenings. On the other hand, coca butter, the main fat used in chocolate bars is considered ideal when it is crystallized in the βV polymorph.
A useful piece of information for the fat industry when creating new edible fats comes from knowing the arrangement of the molecules (i.e. mono-layer or bi-layers) and the thickness of the nanocrystals. This information can help with engineering small or large nanocrystals.
Food products are multi-components materials, where fats might be mixed with proteins, carbohydrates and emulsifiers or stabilizers. It is not easy to study multi-component materials using X-rays, as the intensity obtained is the superposition of each and all the components. Hence, the investigation of multi-component systems starts with only one of those components to which other elements are added, one at a time, to understand what the intensity represents.
This presentation will show some X-ray results for different edible fats in the SAXS and WAXS region with the aim of showing the steps needed to follow when one wants to understand the effect of adding ingredients.
Dr. Yongfeng Ai, Assistant Professor – University of Saskatchewan
Dr. Yongfeng Ai is an Assistant Professor and Saskatchewan Ministry of Agriculture Endowed Research Chair in Carbohydrate Quality and Utilization in the Department of Food and Bioproduct Sciences at the University of Saskatchewan. The primary goal of his Carbohydrate Chemistry and Utilization Program is to promote value-added utilization of carbohydrates in foods, feeds and bioproducts. Specific research areas include:
(1) Chemical, physical and enzymatic modifications of starch and other carbohydrates for novel industrial applications
(2) Development of resistant starch, dietary fiber, and low-glycemic foods and feeds to improve the health of humans and animals
(3) Use of novel processing methods to enhance functional properties and nutritional quality of carbohydrates in pulses and cereal grains
Utilizing synchrotron-based-x-ray computed tomography to visualize the microscopic structure of non destructive starch hydrogels