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Wood biorefining currently involves large-scale industrial processes where a notable portion of raw materials, namely hemicelluloses and lignin, are either lost with the process water, degraded, or burnt for energy. Value added utilization of polymeric hemicelluloses is challenging due to their intermediate molar mass and the presence of other wood components, such as phenolic residues or wood extractives. Oil-in-water (O/W) emulsions represent a diverse and abundant class of applications in which the natural properties of wood hemicelluloses are beneficial. In the current work, we present highly promising new technical alkyd paint emulsion systems stabilized with hardwood glucuronoxylans (GX) and softwood galactoglucomannans (GGM). Samples from three isolation methods and their further fractionation by ethanol precipitation were systematically compared with regard to hemicellulose composition, interfacial activity, and functionality in emulsions. Emulsification of alkyd resins was successful with both GX and GGM obtained by various biorefining strategies. The highest emulsion stability over storage was achieved using crude non-purified GX and GGM fractions, and was correlated with the presence of phenolic compounds and extractives, interfacial activity, and small droplet size. Hardwood GX and softwood GGM are envisioned as natural emulsifiers of alkyd O/W emulsions, which are examples of diverse and abundantly-used technical dispersions. This study can be utilized as a guideline for targeted extraction of hemicelluloses with desired functionality, and as a protocol for developing environmentally-compatible industrial dispersions.

Funding Information: P.P. and F.V. acknowledge the Academy of Finland (grant numbers P.P.: 315768 and F.V.: 316244). B.M.R. and F.V. acknowledge the European Union's Horizon 2020 research and innovation program funding under grant agreement No. 798917 and No. 836071, respectively. The authors acknowledge facilities and technical support by Nanomicroscopy Center at Aalto University. Funding Information: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Fabio Valoppi reports financial support was provided by Academy of Finland. Fabio Valoppi reports financial support was provided by European Union's Horizon 2020 research and innovation program. Paavo Penttila reports financial support was provided by Academy of Finland. Braulio Macias-Rodriguez reports financial support was provided by European Union's Horizon 2020 research and innovation program. Fabio Valoppi has patent #FI20225150 pending to University of Helsinki. Mamata Bhattarai has patent #FI20225150 pending to University of Helsinki.P.P. and F.V. acknowledge the Academy of Finland (grant numbers P.P.: 315768 and F.V.: 316244). B.M.R. and F.V. acknowledge the European Union's Horizon 2020 research and innovation program funding under grant agreement No. 798917 and No. 836071, respectively. The authors acknowledge facilities and technical support by Nanomicroscopy Center at Aalto University. Funding Information: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Fabio Valoppi reports financial support was provided by Academy of Finland . Fabio Valoppi reports financial support was provided by European Union's Horizon 2020 research and innovation program. Paavo Penttila reports financial support was provided by Academy of Finland . Braulio Macias-Rodriguez reports financial support was provided by European Union's Horizon 2020 research and innovation program. Fabio Valoppi has patent #FI20225150 pending to University of Helsinki. Mamata Bhattarai has patent #FI20225150 pending to University of Helsinki. Publisher Copyright: © 2022 The Authors Oleogels are a class of solid-fat mimetics that contain a large fraction of oil. Most of these materials have low stiffness and poor oil-binding capacity at commercially viable concentrations, which limits their application in the food and cosmetic industries. To improve their mechanical behavior, we exploited the concepts of particulate-filled materials by developing oil-continuous monoglyceride composites reinforced with crystalline cellulose of various sizes. Cellulose was used as the reinforcing filler material due to its strength, biodegradability, and abundance. The composites gradually stiffened and became more brittle with a progressive increase of the cellulose weight fraction as the maximum packing fraction of fillers approached. This was manifested as an increase in the viscoelastic moduli and yield stress, consistent with the size of the filler. Based on differential scanning calorimetry, X-ray diffraction, X-ray scattering analyses, and microscopic analyses, the inert surface of crystalline celluloses provided a solid substrate for the crystallization of monoglycerides, favoring the lamellar stacking of monoglyceride molecules during the composite oleogel formation regardless of the cellulose size. The present study suggests that cellulose is a suitable bio-based filler material to obtain mechanically strong oleogels suitable for high-shear applications e.g., in food and pharmaceutical industries.