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.

Who wants to be (ERC) millionaire?

The FoMSci group leader, Kirsi Mikkonen, received the prestigious and extremely competitive European Research Council Consolidator Grant (ERC-CoG) for her innovative and challenging project entitled: “Green Route to Wood-Derived Janus Particles for Stabilized Interfaces – PARTIFACE”. The project is about developing a novel type of Janus particles, that are bi-facial particles where the two “faces” of the particle have opposite properties. Imagine an apple, half red and sweet and half green and sour, that is a Janus apple! Kirsi will develop these new particles using renewable resources. Kirsi’s Janus particles will be able to stabilize emulsions from a physical and chemical perspective, meaning that the emulsions will look and smell the same even after months of storage.

The splendid news came in a very cryptic email from the Council. “I got the ERC grant” Kirsi said staring amazed at her phone. The rumor spread in the corridor and everybody started exulting and congratulating Kirsi. This year only five researchers in the whole Finland received this important grant worth two million euros. Kirsi’s ERC project is the first granted to the Faculty of Agriculture and Forestry of the University of Helsinki.

Kudos to Kirsi from all your research group. We are extremely proud of you!

PICTURES:

Happy faces at the party for the recently funded Assist. Prof. Kirsi Mikkonen’s ERC-CoG Partiface project.

ERC cake designed and prepared by Ida Nikkilä

FreshPack – new business from research ideas

We are excited to start our new research and commercialization project “FreshPack” since the beginning of September 2019. The project aims to identify the market potential and create new business from the research idea developed by the Food Materials Science Research Group. Assist. Prof. Kirsi Mikkonen leads this project and other members of the team are Project Planner Emmi Korjus, Doctoral Student Jaison Sithole, Commercialization Officer Petri Junttila, Prof. Maija Tenkanen, Postdoctoral Researcher Elina Jääskeläinen, and Prof. Johanna Björkroth.

Almost half of the global fruit and vegetable production is lost as food waste. FreshPack fights this problem with a novel active packaging component that maintains the quality, microbial safety, and freshness of plant-based products and therefore improves their shelf-life. We have started the further development of our active component along with testing it as part of the existing distribution chain. The component is bio-based and works well in both open and sealed packages.

In September, Emmi and Petri participated in the Smart Packaging Conference in Hamburg, Germany, which was a great kick-off for the project. The conference brought together other active and intelligent technology developers, brand owners, packaging producers, and processing experts to discuss new opportunities and applications for intelligent and active packaging. Among many good presentations, there were speakers from some companies targeting to solve similar problems as FreshPack. It was fruitful to explore the field and see different approaches and solutions to the same challenge.

Follow us for updates along the way from a great invention towards even greater commercial product!

 

Source of the fruit picture: Uni Material Bank

Writing retreat in Lammi 7.-9.10.2019

Our previous writing and networking retreat in October 2018 was such an excellently productive and positive experience that again in October 2019, the Food Materials Science Research Group, reinforced with Vice Dean of Research, Prof. Maija Tenkanen and her Carbohydrate Enzymology and Chemistry Group, and the Aalto Protein Team, led by Prof. Emma Master, spent three days at the Lammi Biological Station of the University of Helsinki.

The classroom was reserved for quiet working, where we reached an amazing flow experience for writing. Group meetings, face-to-face or via Skype, and many scientific discussions were held outside of the classroom. Fabio introduced us a modern idea about writing together an article in 24 hours, which we experimented. We enjoyed lively conversations, did a hiking trip to the nearby Evo forest area, picked mushrooms, and tasted them as an evening snack. Of course we enjoyed also delicious meals at breakfast, lunch, coffee breaks and dinner. The food was wonderful, and we could focus all our energy in writing. Evening sauna by the Pääjärvi lake was relaxing, and swimming in the fresh cold water kept our minds clear and sharp.