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A multistage process was employed to obtain value-added products from brewer's spent grain (BSG). This paper is focused on the production and characterisation of cellulose nano-fibres (CNF) as one of the products obtained during the complete process. In the first stage, protein-rich liquor was separated via the alkaline (NaOH) treatment of dried BSG and stored for further utilisation. In the second stage, bleaching treatments were conducted to separate cellulose, which was later converted to CNF by high-pressure homogenisation. The lignocellulosic product from each step was analysed for its chemical composition by means of alkaline hydrolysis combined with the HPEAC method. The thermal properties were measured using thermogravimetric analysis (TGA). The morphology was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). X-ray diffraction (XRD) was done to observe changes in crystallinity. The nano-cellulose produced can be regarded as a value-added material from the bio-refinery of BSG along with numerous already-reported products. [ABSTRACT FROM AUTHOR]

A multistage process was employed to obtain value-added products from brewer’s spent grain (BSG). This paper is focused on the production and characterisation of cellulose nano-fibres (CNF) as one of the products obtained during the complete process. In the first stage, protein-rich liquor was separated via the alkaline (NaOH) treatment of dried BSG and stored for further utilisation. In the second stage, bleaching treatments were conducted to separate cellulose, which was later converted to CNF by high-pressure homogenisation. The lignocellulosic product from each step was analysed for its chemical composition by means of alkaline hydrolysis combined with the HPEAC method. The thermal properties were measured using thermogravimetric analysis (TGA). The morphology was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). X-ray diffraction (XRD) was done to observe changes in crystallinity. The nano-cellulose produced can be regarded as a value-added material from the bio-refinery of BSG along with numerous already-reported products.

The structure of wood is so compact that enzymes are too large to penetrate into the structure and thereby attack the wood components for modifications that can be valuable for various purposes. Here we present a pretreatment method based on traditional kraft pulping, which opens the wood structure, so that enzymes are able to attack the wood components. To study this kind of chemical pretreatment, spruce wood samples were treated at similar conditions used in kraft cooking at varying intensities (H-factors). To verify if the structure was "opened" for enzymes, the pretreated wood samples were incubated with a cellulolytic culture filtrate, and the released reducing sugar concentration after the enzymatic hydrolysis was measured. The results indicated that unpretreated wood fibers could not be attacked by the enzymes, but already relatively mild pretreatment was sufficient for letting the culture filtrate attack wood polysaccharides, and more intensive treatments opened the structure further. The mildest treatments did not cause any significant yield losses of lignin (Klason lignin). Some galactoglucomannans were however lost during the pretreatments. The mechanisms behind the effect and the technical significance of the method are discussed. [ABSTRACT FROM AUTHOR]