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

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

Influence of Temperature and Drying Time on Extraction Yield of Phenolic Compounds from Grape Pomace Variety “Portogizac”

The influence of drying temperature (60 °C, 70 °C, 80 °C) and fluid-bed drying time (90 min, 135 min, 180 min) on the extraction yield of phenolic compounds and antioxidant activity of extracts were investigated. The content of phenolic compounds and antioxidant activity of extracts obtained from wet grape pomace (WGP) were 73.83 mgGAE gdb–1, 42.24 mgCE gdb–1, 30.53 mg gdb–1, and 0.35 ginhDPPH gdb–1 for total phenolic compounds (TPC), total flavonoids (TF), total extractible proanthocyanidins (TPA), and antioxidant activity (AA), respectively. The applied drying conditions caused the reduction of content of all phenolic compounds down to 13.2 %, 43.1 %, 15.3 % and 21.0 % for TPC, TPA, TF and AA, respectively. The most abundant individual phenolic compound in grape pomace extracts was catechin (5.14 – 8.52 mg gdb–1). The highest content of observed compounds was retained when applying drying temperature below 70 °C for 90 minutes

Optimization of the extraction process of polyphenols from Thymus serpyllum L. herb using maceration, heat- and ultrasound-assisted techniques

Despite the fact that Thymus serpyllum is well-known medicinal plant and its chemical profile and biological activity have been investigated, there is no detailed study regarding the influence of different techniques and conditions on the extraction of polyphenolic compounds from Serpylli herba. The aim of this study was optimization of the extraction parameters that improves the efficiency of polyphenols extraction from T. serpyllum: particle size, solid-to-solvent ratio, solvent type and extraction time, by using maceration, heat- and ultrasound-assisted extraction (HAE and UAE). The extraction efficiency was expressed via total polyphenol content (TPC) and total flavonoid content (TFC). The statistical analysis (one-way ANOVA and full factorial design) has revealed that the optimal conditions for achieving the best polyphenols yield were particle size of 0.3 mm, 1:30 solid-to-solvent ratio and 50% ethanol, as environmentally friendly extraction medium, while extraction time has not shown statistically significant influence on polyphenols concentration, in all procedures. Under these conditions, the measured TPC was 26.6 mg GAE/L in maceration, 29.8 mg GAE/L in HAE and 32.7 mg GAE/L in UAE, which was in agreement with the predicted values, while TFC was 143 mg CE/L, 12.4 mg CE/L and 16.7 mg CE/L for maceration, HAE and UAE, respectively. According to total polyphenols yield, the efficiency of the extraction methods for all variables was ranked by significance in the following order: UAE gt HAE gt maceration, whereas total flavonoids yield was the highest in UAE, although there was no statistically significant difference between maceration and HAE. According to our results, UAE could be selected as the most successful and suitable technique for extraction of bioactive polyphenolic compounds from Serpylli herba. Using LC/MS and HPLC analysis, 9 polyphenolic compounds were identified and quantified: 6,8-Di-C-glucosylapigenin, chlorogenic acid, 6-hydroxyluteolin 7-O-glucoside, caffeic acid, luteolin 7-O-glucuronide, apigenin glucuronide, salvianolic acid g isomer, rosmarinic acid and salvianolic acid I. This study was an initial step in production of polyphenols-rich wild thyme extracts aimed to be used for formulation of foodstuffs and medicines