Bio-based Products from Lignocellulosic Waste Biomass: A State of the Art

This review presents data on the chemical composition of harvest residues and food industry by-products as widely abundant representatives of lignocellulosic waste biomass. Pretreatment methods, with special emphasis on biological methods, are presented as an important step in utilization of lignocellulosic waste biomass for the production of sustainable biofuels and high-value chemicals. Special attention was paid to the methods of lignin isolation and its possible utilization within lignocellulosic biorefinery. The objectives of circular bioeconomy and the main aspects of lignocellulosic biorefinery are highlighted. Finally, current data on industrial, pilot, and research and development plants used in Europe for the production of a variety of bio-based products from different feedstocks are presented. This work is licensed under a Creative Commons Attribution 4.0 International License

Release of Fermentable Sugars from Corn Silage – The Effect of Biological Pretreatment

Lignocellulose biomass, as a renewable and biodegradable carbon source, provides a wide range of valuable bioproducts. Their utilization requires an efficient conversion process to break down the complex and variable chemical structure of lignocellulose. In this work, a solid-state fermentation-based pretreatment method for the release of fermentable sugars from corn silage was investigated. The optimal process conditions for water-soluble sugar extraction were initially explored by response surface methodology with the aim to achieve the maximum sugar concentration in the extracts. The optimal extraction conditions were determined: t = 30 min; the liquid-solid ratio L/S = 25 mL g–1; n = 170 rpm; and T = 30 °C. The changes in the content of water-soluble sugars (glucose, fructose, sucrose, maltose, maltotriose) were analyzed during seven days of fungal treatment

Influence of extraction type on the total phenolics, total flavonoids and total colour change of different varieties of fig extracts

The study examined the influence of ultrasound-assisted extraction and solid-liquid extraction with 80% of aqueous ethanol solution on the total phenolics, total flavonoids and total colour change of extracts from five different varieties of figs (Bjelica, Termenjača, Crnica, Bružetka bijela and Šaraguja). The total phenolic content was determined by using Folin Ciocalteau assay. The content of total flavonoids was measured spectrophotometrically by using the aluminium chloride colourimetric assay. Colour changes were obtained by chromameter CR-400 (Minolta) in L*a*b* colour model. Ultrasound-assisted extraction showed highest total phenolic content (up to 13.72%) and total flavonoid content (up to 18.55%) compared to classic solid-liquid extraction. According to given results total colour changes of extracts were reduced (up to 32.1%) applying ultrasound. Significant difference was found between the total phenolic and total flavonoid content according to different varieties of fig

An Application of Image Analysis and Colorimetric Methods on Color Change of Dehydrated Asparagus (Asparagus maritimus L.)

Shape and color are key factors in quality evaluation of fresh asparagus (Asparagus maritimus L.). Typical green color of asparagus comes from the chlorophyll, pigment which has been degradated during drying process. The aim of this paper was to compare color changes of asparagus dried in laboratory tray drier equipment at different temperatures (40 °C, 50 °C, 60 °C and 70 °C) at airflow velocity of 2.75 ms-1. Color changes were obtained by digital image analysis in RGB color model and by chromameter in L*a*b* color model. Basic elements of image analysis system were low voltage halogen lamps with reflector, digital camera and programs for image pre-processing and analysis. Mean values of color parameters, color changes and correlation coefficients for asparagus were calculated for both color models. An analysis showed statistically significant influence of drying temperature on hue angle and total color change for both chosen color models of dehydrated asparagus. Represented results show that there was no statistically significant difference according to color changes between drying at 50 °C and 60 °C. Calculated correlation coefficient between color changes for used models was found to be 0.9167

Kinetic models for supercritical CO2 extraction of oilseeds - a review

Ekstrakcija uljarica superkritičnim fluidima u posljednjih nekoliko desetljeća nailazi na sve veće zanimanje u pogledu njene moguće komercijalne primjene. Razlog tome su brojne prednosti superkritične ekstrakcije, u odnosu na klasične ekstrakcijske postupke pomoću organskih otapala, kao i činjenicu da CO2, kao otapalo, ima oznaku GRAS te se smatra potpuno sigurnim za primjenu u proizvodnji i preradi hrane. Superkritična ekstrakcija, na industrijskoj razini, trenutno je usmjerena na dekofeinizaciju kave i čaja, ekstrakciju hmelja, proizvodnju sezamovog ulja te ekstrakciju pojedinih naftnih derivata. Za moguću industrijsku primjenu, ekstrakcije uljarica superkritičnim fluidima, od iznimne je važnosti ispitati primjenjivost odgovarajućih matematičkih modela koji omogućuju prijenos rezultata istraživanja iz laboratorijskog u industrijsko mjerilo. U radu je dan pregled značajnijih matematičkih modela objavljenih u literaturi, koji se koriste za opisivanje kinetike ekstrakcije superkritičnim fluidima.The supercritical fluid extraction of oilseeds is gaining increasing interest in commercial application for the last few decades, most particularly thanks to technical and environmental advantages of supercritical fluid extraction technology compared to current extraction methods with organic solvents. Furthermore, CO2 as a solvent is generally recognized as safe (GRAS). At present moment, supercritical fluid extractions on a commercial scale are limited to decaffeination, production of soluble hops extracts, sesame seed oil production and extraction of certain petroleum products. When considering industrial application, it is essential to test the applicability of the appropriate model for supercritical fluid extraction of oilseeds used for scale up of laboratory data to industrial design purposes. The aim of this paper is to review the most significant kinetic models reported in the literature for supercritical fluid extraction

Technological Solution for the Sustainability of the Destructive Distillation of Wood in Classic Horizontal Retorts

Charcoal production in retorts involves the pyrolysis i.e. thermal decomposition of wood in the absence of oxygen/air. The by products of this thermo-chemical process are tar, pyroligneous acid and wood gas. Pyroligneous acid can recover in several useful organic products by fraction distillation. However, the modern synthetic ways of their production are more economic, so that distillation of pyroligneous acid becomes irrational and is an abandoned procedure in “Factory of Wood Processing in Belišće”. The factory in full capacity makes about 25 t of pyroligneous acid daily, which is recognised as an environmental pollutant and hence cannot be allowed to escape into streams. Therefore, to continue wood charcoal production it was necessary to dispose of pyroligneous acid in an environmentally friendly manner. Four possible solutions to this problem were proposed. The innovative and acceptable solution found in the partial plant reconstruction that assumes direct combustion of exhaust retort gases instead of their condensation. The reconstruction gave several positive effects: the condensation phase was eliminated; retort gases became the main heating fuel that should provide ample heat for the plant; wastewater and gases are environmental-friendly