Members of FoMSci Participated in the ACS Spring 2021 Conference

The American Chemical Society (ACS) annually hosts two major conferences on chemistry, one in the spring and the other in the autumn. Members of the Food Materials Science group in the University of Helsinki have regularly participated in the ACS Spring events since 2005 to present the results of our work. While the ACS Spring 2020 was cancelled due to the coronavirus pandemic, in 2021 the conference was held entirely online via Zoom, with live presentation sessions being held on April 5th-16th and on-demand sessions between April 19th-30th. Several of our members received the opportunity to present our research in the oral presentation sessions. Below is the list of presentation titles and the contributing authors, with the presenters in bold:

  1. Hardwood xylans show prebiotic effect on rodents – Emma Kynkäänniemi, Maarit Lahtinen, Ching Jian, Anne Salonen, Kirsi S. Mikkonen, Anne-Maria Pajari
  2. Comparative emulsion stability study of hot water-extracted birch glucuronoxylans – Felix Abik, Thao Minh Ho, Kirsi S. Mikkonen
  3. Lignin nanoparticles and nanocelluloses for the removal of pharmaceutical residues from water – Melissa Agustin, Mari Lehtonen, Kirsi S. Mikkonen
  4. Green route fabrication approaches of lignin nanoparticles: a comparison study – Patricia Figueiredo, Melissa Agustin, Maarit Lahtinen, Sami-Pekka Hirvonen, Paavo Penttilä, Kirsi S. Mikkonen
  5. Analytical insights on lignin-carbohydrate complexes in softwood and hardwood extracts – Danila Morais de Carvalho, Maarit Lahtinen, Martin Lawoko, Kirsi S. Mikkonen

We normally would have attended the conference live in the United States, but as it was held entirely online, we could participate without having to travel from Finland to the United States. The format also allowed us to watch the presentations that we found interesting, despite being spread across different divisions, and move between the different parallel sessions seamlessly. For example, most of us were involved in the Division of Cellulose and Renewable Materials (CELL), but we could easily switch to sessions within the Division of Colloid and Surface Chemistry (COLL), Agricultural and Food Chemistry (AGFD), or Analytical Chemistry (ANYL), to name a few. This allowed us to listen to various topics of our choice, maximizing the insight we got from the conference.

However, the sessions were organized based on the Pacific Daylight Time, which is 10 hours behind our current Eastern European Summer Time in Finland. Therefore, the sessions of the day began at 7 PM Helsinki time, and closed early in the morning. Consequently, a special mention goes to those  who had to present in the early hours of the morning. It also became rather difficult to watch the presentations that were scheduled later in the day. Nevertheless, an option to allow presenters to open their presentations to be available for on-demand viewing until April 30th was available, which allowed us to watch many of the presentations that we missed, was in parallel with other presentations, or even fell asleep while watching due to the late hours.

Overall, despite missing the direct interaction aspect of traditional conferences, we still managed to obtain as much knowledge and experience as we can from ACS Spring 2021. We look forward to our next participation in an ACS Meeting!




ROCK – building new knowledge to valorize forest resources

ROCK: ROle of lignin Carbohydrate complexes as Key to stable emulsions project has been completed. The project was designed to valorize forest resources, especially those from Nordic forests. Hemicelluloses-rich extracts, obtained by an environmentally-friendly water-extraction method was previously identified as a functional substance for stabilizing emulsions. Although rich in hemicelluloses, they also contain a certain amount of other polysaccharides and lignin co- extracted. When we commenced this project, the reason for the excellent stability performance of hemicellulose extracts as emulsifiers was still unclear and our hypothesis was that at least some of the residual lignins could be covalently linked to the polysaccharides forming so-called lignin-carbohydrates complexes (LCC). Such hybrid composites have two distinct regions, one more hydrophilic (hemicellulose part) and other more hydrophobic (lignin part). As a result, each region can interact with the different phases of the emulsion, possibly explaining the emulsion stability achieved using hemicellulose-based emulsifier. Our main aim was to investigate the presence of LCC in hemicelluloses extract and identify the role of such structures in emulsion stabilization. To do this we investigated the structures and functionalities of hemicelluloses extracts. In the initial part of this study, we characterized various types of hemicelluloses extracts obtained from birch and spruce wood. Using a combination of fractionation and advanced identification techniques, we demonstrated that some of the lignin residues in the extracts were involved in the formation of LCC linkages of various types (i.e., phenylglycoside, benzylether, and gamma-ester). A previous posted blog with these findings can be found here.

Next, we investigated how the different polymer populations in the hemicelluloses extract, including the LCC structures, are distributed between the emulsion phases (i.e., droplet interface and continuous phase) and what aspects drive such distribution. Beyond differences in the appearance (see figure), we discovered that the hemicelluloses populations in the various emulsion phases also differed in terms of their chemical and structural aspects. The residual lignin is a component of fundamental importance for the hemicelluloses orientation during emulsification and for the stability of the emulsions. Moreover, the various LCC structures identified in the hemicelluloses extracts were fractionated between emulsion phases depending of their type. In summary, ROCK provided the cornerstone to better understand the composition of hemicelluloses extracts and their functionality in emulsion, pushing the wood-hemicelluloses a step closer to added-value applications.

The ROCK project was funded by Tandem Forest Value and led by Assoc. Prof. Kirsi Mikkonen (University of Helsinki, Finland) and Prof. Martin Lawoko (Royal Institute of Technology, Sweden).