New AoF postdoc grant addresses pharmaceutical pollution in water

Do you know that you might be taking in medicines every day without you knowing it? It is possible when the water you drink is contaminated with pharmaceutical pollutants. These are residual drug molecules, which stay in water because conventional wastewater treatment methods cannot completely remove them. Pharmaceutical pollutants affect water resources, including drinking water in various parts of the world, and may pose health hazards to humans. The good news, though, is that the recently awarded postdoc grant to Melissa Agustin by the Academy of Finland (AoF) offers a potential solution to this global problem on pharmaceutical pollution. The project entitled: “Pickering emulsion-based synthesis of lignocellulose aerogels as adsorbents for pharmaceutical pollutants (PickPollutants)” will develop bio-based materials capable of removing residual drug molecules from water. This multidisciplinary project will employ the expertise in emulsion and aerogel research of the FoMSci group, with support from local and international collaborators: Aalto University, University of Eastern Finland, Finnish Environmental Institute, and Hamburg Institute of Technology.

The PickPollutants project is among the 15% successful applications in natural sciences and engineering to be granted a three-year funding by the AoF in 2020. Yearly, the AoF grants funding to high-quality scientific research in various fields with the aim of contributing to the renewal, diversification and increase internalization of Finnish research.

Kudos to Melissa´s new project! This shows that here in FoMSci, we care not only about the foods you eat, but also about the water you drink!

Links between lignin and hemicelluloses in spruce extract

The Food Materials Science research group continues to innovate in the use of Nordic forest resources in advanced applications for food and other novel materials. For this, a deep understanding on the chemical and structural aspects of wood components is crucial. Assessment of cellulose, hemicelluloses, and lignin alone is needed, but also the identification and elucidation of linkages between those structures: the so-called lignin-carbohydrate complexes (LCCs). Despite of paramount importance for applications, the identification of LCC bonds is challenging because of their relatively low frequency in wood extracts.

A recent research article by Danila Carvalho et al. (https://doi.org/10.1021/acssuschemeng.0c03988) tackled this challenge and improved the identification of LCC bonds in spruce hot water extract using an elegant combination of fractionation techniques, including chemical, enzymatic, and physical methods. Such techniques resulted in the fractionation of LCC bonds and enabled the identification of three types of LCCs, namely: phenylglycoside (PG), benzylether (BE) and gamma-ester (GE). This research developed an efficient analytical methodology for LCC identification, which may facilitate the study of LCC functionalities and, consequently, open novel opportunities of applications for wood-based derivatives.

This research was a result of the collaborative project: “Role of lignin carbohydrate complexes as key to stable emulsions” (ROCK), funded by Tandem Forest Values programme by Kungliga Skogs- och Lantbruksakademien (KSLA), Sweden, and led by Assist. Prof. Kirsi Mikkonen (University of Helsinki, Finland) and Assoc. Prof. Martin Lawoko (Royal Institute of Technology, Sweden).

The open access article is available at https://doi.org/10.1021/acssuschemeng.0c03988

PARTIFACE: Green route to wood-derived Janus particles for stabilized interfaces

We are extremely thrilled to start our new research project “PARTIFACE” since the beginning of June 2020, supported by the European Research Council and led by Assist. Prof. Kirsi S. Mikkonen. This project aims to develop a green conversion route using enzymatic crosslinking to build a novel concept, in which tailored bi-facial “Janus” particles will be prepared from two of the most abundant, but underexploited wood-based biopolymers: lignin and hemicelluloses.

Using environmentally friendly technology, this project will design sophisticated and sustainable hierarchical architectures from the abovementioned biopolymers. Due to their two ‘faces’ with opposite properties, these tailored wood-based particles are expected to have a superior capacity to stabilize emulsion interfaces.

Therefore, we envision a breakthrough in interface and colloid science, contributing to more sustainable use of the Earth’s resources.

New work reveals detailed features of spruce gum (galactoglucomannan) in water

The Food Materials Science group studies the applicability of spruce gum in dispersion-based systems, such as food, beverages, cosmetics, and chemicals. To formulate applications of spruce gum to produce high quality products, knowledge on its solution properties is very essential.

A recently published article (https://doi.org/10.1016/j.carbpol.2020.116368) by Mamata Bhattarai et al. reveals that spruce gum forms higher-order structures in water, such as aggregates and colloidal particles. We demonstrated this, for the first time, by fractionating and studying all the fractions of spruce gum using asymmetric field-flow fractionation and a combination of light scattering and electron microscopy.

Spruce gum is mainly composed of galactoglucomannan polysaccharides, but also other structures are co-extracted from spruce wood with the polysaccharides. Unpurified spruce gum containing high levels of lignin occurred in water in the form of polysaccharide-aggregate-particle mixture. Spruce gum after purification by ethanol precipitation did not show particles, but the aggregates still existed. Characterization of this unique mixture of spruce gum was challenging; thus, several parameters during the analytical fractionation had to be optimized. The article discusses several aspects about challenges to fractionate complex polysaccharide mixtures and possible approaches to address them.

The work was a result of excellent collaboration between the FoMSci group (Department of Food and Nutrition, University of Helsinki), Department of Physics (University of Helsinki), and the University of Natural Resources and Life Sciences (BOKU), Austria.

The article is available as open access: https://doi.org/10.1016/j.carbpol.2020.116368

Will future packaging be grown from fungi?

Think about expanded polystyrene and try to imagine something that works like polystyrene, but is much more environmentally friendly, very sustainable, and an economic material.

Fungal mycelia are versatile, highly productive, and sustainable sources for biocomposites to replace conventional plastics. However, only a few fungal strains have been characterized in composites and numerous strains remain unexplored. Many plant residue materials, such as side streams from food production could be used as feeding substrates for mycelia. A research article by Zeynep Tacer-Caba et al. (https://doi.org/10.1016/j.matdes.2020.108728) explored this field and studied novel fungal strains, feeding substrates, and dynamic mechanical properties of mycelium composites for the first time at a broad moisture gradient. The research was conducted within the Academy of Finland –funded project Reassembly of fungal polysaccharides for biocompatible interfaces (REPLY). 

The champion of novel mycelium composites, Agaricus bisporus, gave high stiffness and moisture-resistance. The dense structure and rich chemical composition of rapeseed cake made it a potent feeding substrate for mycelia. In this work, the compressive strength of mycelium composites ranged between 17 and 300 kPa. Therefore, mycelium composites may be considered as competitors of expanded polystyrene, as the latter have similar compressive strength (69–400 kPa).

 All tested mycelia composites, either with rapeseed cake or oat husk as feeding substrates, had rather low water uptake at moderate ambient humidity. Therefore, all samples – irrespective of the mycelium and substrate types – seemed to be resilient to moisture. Will future packaging be grown from fungi?

Okay, this is remote work!

COVID-19 forced the FoMSci research group to work remotely.  We rapidly took use of versatile online tools and Kirsi started to host weekly group meetings. Staying home made us realize how important human interactions are in working life, and hence we also opened remote coffee breaks. A video call over a cup of morning coffee makes things seem more normal again. 

While we do not have access to laboratories, otherwise moving to remote working was an easy step. It also proves to be an incredibly efficient way to advance writing publications or planning new project proposals. FoMSci has been very productive already! 

Yet, we cannot deny how much we miss working in the laboratories and the hands on work.  

During regular working days, one can easily reach a daily goal of 10K steps of walking. In remote working, UniSport video exercises help us keep in shape, and many of us has given a try to various workouts. A daily routine of stretching and getting fresh air is good for the mood!

FoMSci thanks the University of Helsinki for an excellent job during the corona crisis. The university offers to co-operate with hospitals and help authorities with their facilities and laboratory equipment. The administration and IT helpdesk are working brilliantly by clear communication and instructions, which has made these exceptional times and the digital leap much easier for teachers and researchers. We are working together for a better future. #WeAreHelsinkiuni

ENVISION: Oil-water interface characterization

Ever wonder why your salad dressing can be so smooth, even though it is basically made of oil and vinegar? Vinaigrette, like mayonnaise, milk, and ice cream, are examples of what we call emulsions. Commonly used in the pharmaceutical, cosmetics, biotechnology and food industries, emulsions let us enjoy liquid products that feel good to our senses, while at the same time they protect bioactive compounds contained inside the mixture. They are formed by mixing two liquids that do not spontaneously mix (typically oil and water) and stabilized by a surfactant. The behaviour and properties of the surfactant on the border between oil and water determine the stability of emulsions, but the relationship between how the surfactants arrange themselves on the oil droplets and how they stabilize the mixture is still unknown. Our project, called “ENVISION”, is ongoing to provide insights about interfacial properties of emulsions. This project is funded by The Academy of Finland (1.9.2019–31.8.2023), led by Assistant Professor Kirsi Mikkonen, and conducted by Postdoctoral Researcher Thao Minh Ho and Doctoral Student Felix Abik.

In this project, we will be using a technique called atomic force microscopy (AFM). Imagine entering a dark room; your first instinct would be to look for the light switch on the wall by touching it with your hand, feeling the surface until you found the switch. With AFM, we are doing the same thing, but with a much smaller ‘hand’ to ‘touch’ the surface of our emulsions and make an image of what is happening on the droplets. We have successfully investigated trials on the preparation of emulsions with different surfactants. Next steps will be the characterization of the stability of emulsions. This will be followed by development of an innovative method for interfacial characterization using AFM. The result of this project will potentially open new scenarios in manipulating and designing intelligent delivery systems in forms of emulsions, for many bioactive compounds in numerous applications in technology and life sciences.

Photo: Felix and his doctoral thesis committee (who met for the first time just before the COVID-19 outbreak spread in Finland). From left to right: Postdoctoral Researcher Thao Minh Ho, University Researcher Laura Flander, Professor Orlando Rojas (Aalto University), Assistant Professor Kirsi Mikkonen (PI), University Lecturer Marianna Kemell, and Doctoral Student Felix Abik.

Have FUN with OLEOgels! New HiPOC grant for turning oleogels into functional materials

In December 2019, Fabio Valoppi obtained the Proof of Concept grant (HiPOC) from the Helsinki Institute of Life Science (HiLIFE) of the University of Helsinki for his project entitled “Functional oleogels with health enhancing ability (FUN-OLEO)”. Within this project, Fabio and his collaborators are transforming oleogels into novel functional materials using an unusual route.

Oleogels are considered the “fat of the future” and were developed to replace saturated, hydrogenated and trans fats in food products. They contain high fractions of liquid oil (85 – 99.5%) entrapped in a network made of structuring molecules. However, oleogels have some drawbacks that slow down their application in certain type of foods. Fabio came up with a novel concept that could extend oleogels’ applicability to a broader range of food products while introducing a new health enhancing ability: this is how you kill two pigeons with one stone!

The purpose of this HiPOC grant is to accelerate the patenting of Fabio’s novel idea. Unfortunately, we cannot reveal too much about the idea behind the project at this time. We can only say that we already obtained encouraging results! Stay tuned for more updates and to find out how this project will evolve.

Doing GOOD

As highlighted in our previous blog post, food and pharmaceutical industries could utilize birch- and spruce-derived hemicelluloses and lignin in future. In addition to their promising emulsion stabilizing properties, the fiber- and polyphenol-rich birch and spruce extracts could be good for our gut health. Therefore, the effects of wood-derived extracts on gut health are the focus of the GOOD project. This project has recently received funding from the Jane and Aatos Erkko Foundation. Doctoral student Emma Kynkäänniemi, postdoctoral researcher Maarit Lahtinen, university lecturer Anne-Maria Pajari and assistant professor Kirsi Mikkonen form a good project team!

A group of rats got an exciting addition to their diets: polyphenol-rich birch extract. The diet was tasty and all the rats gained weight normally. Next, we will investigate the effects of the feeding period on gut health, analyzing, for example, the gut microbiota and their metabolites from the fecal samples of the rats. The results of the GOOD project will bring us many steps closer to the goal of transforming wood into food.

New findings on wood extracts and lignin nanoparticles

A recent research article by Maarit Lahtinen et al. (https://doi.org/10.3389/fchem.2019.00871) sheds new light on the chemical structures that make wood extracts so efficient in emulsion stabilization. Pressurized hot water extracted hemicelluloses, spruce galactoglucomannans (GGM) and birch glucuronoxylans, contain residual lignin. Some of that lignin may be covalently linked with the hemicellulose structures via lignin carbohydrate complexes. Presence of lignin greatly improves the oxidative stability of emulsions.

Mamata Bhattarai et al. (https://doi.org/10.1016/j.foodhyd.2019.105607) studied how spruce GGM behave in water. GGM show tendency to form physical assemblies during storage, meaning that dissolved hemicelluloses associate with each other and form clusters. This behavior depends on pH, so it is important to take into account when designing future products from GGM.

Alkali-extracted lignin precipitates in acidic pH. Melissa Agustin et al. (https://doi.org/10.1021/acssuschemeng.9b05445) took advantage of this property and developed lignin nanoparticles, with the help of a rapid ultrasonication treatment. The resulting particles were spherical, negatively charged, and very stable in suspensions and emulsions. The underexploited wood components, hemicelluloses and lignin, have promising properties that could be useful in chemicals, pharmaceuticals, and food.