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.
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.
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 mg.sub.GAE g.sub.db.sup.-1, 42.24 mg.sub.CE g.sub.db.sup.-1 30.53 mg g.sub.db.sup.-1 and 0.35 g.sub.inhDPPH g.sub.db.sup.-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 g.sub.db.sup.-1). The highest content of observed compounds was retained when applying drying temperature below 70°C for 90 minutes. Key words: grape pomace, fluid-bed drying, phenolic compounds, antioxidant activity
Modelling of the process of solid-liquid extraction of total polyphenols from soybeans Jokic, S.,J.J. Strossmayer Univ., Osijek (Croatia). Faculty of Food Technology; Velic, D.,J.J. Strossmayer Univ., Osijek (Croatia). Faculty of Food Technology; Bilic, M.,J.J. Strossmayer Univ., Osijek (Croatia). Faculty of Food Technology ...
Czech Journal of Food Sciences,
01/2010, Letnik:
28, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The influence of the solvent, temperature, and extraction time on the extractability of total polyphenols from milled soybeans (variety Ika) was investigated. The study was performed in order to ...select the most suitable solvent (water; 50, 60, 70, and 80% aqueous ethanol) for achieving the highest yield of total polyphenols. The most effective solvent (50% aqueous ethanol solution) was used for monitoring the kinetics and modelling of solid-liquid extraction of total polyphenols from soybeans, average particle size 0.459 mm, at solid-liquid ratio of 20 mL/g (ratio of the solvent volume per g of raw material). The total polyphenols content in the soybean extract was determined spectrophotometrically using Folin-Ciocalteu micro-methods at 765 nm. The applicability of different mathematical models (Peleg, Page, and Logarithmic models) to describe the kinetics of the solid-liquid extraction process of total polyphenols from soybeans was studied as well. The results exhibited a significant influence of the solvent and temperature on the kinetics and extraction yield of total polyphenols from soybeans. The best extraction yield of total polyphenols was obtained using 50% aqueous ethanol solution at 80 deg C after 120 min (4.322 mg GAE/gdb). The extraction yield of total polyphenols in soybean extracts increased by increasing the extraction temperature and extending the duration of the extraction process. The mathematical models applied showed a good agreement with the experimental results, which allows their application in modelling and optimisation of solid-liquid extraction process for the extraction of total polyphenols from soybeans.
Corn silage refers to stalks, leaves and cobs of maize plants that remain in fields after the corn harvest. Commonly it is used as a cattle feed, but recently it has been more often used together ...with cattle manure in biofuel production in anaerobic co-digestion. In this work high-pressure and temperature extraction of phenolic compounds from corn silage was performed. Process parameters (temperature, T = 90 – 180 °C; extraction time, t = 40 – 120 min; liquid – solid ratio, 10 – 20 mL/g; and solvent concentration (10 – 90 % aqueous ethanol, v/v) were studied. Box-Bhenken design was used in order to obtain the maximal extractability of phenolic compounds (namely total phenolic compounds- TPC and total extractible proanthocyanidins - TPA) and the maximal antiradical power (ARP) of obtained extracts. Experimental results of TPC, TPA, and ARP of corn silage extracts were in the range from 10.01 – 72.43 mgGallicAcid Equivalent/gdrybiomass, 0.27 – 3.21 mg/gdrybiomass and 1.25 – 16.76 mgDPPH/mLextract, respectively. Statistical results confirmed that temperature was the most significant factor affecting the observed responses (p < 0.05). Optimal extraction conditions for TPA and ARP were achieved at 180 °C, 120 min using 65 % ethanol and L/S ratio 10 while optimal conditions for TPC were achieved at 180 °C, 120 min using 10 % ethanol and L/S ratio 20. The results of this study evidenced that extracts from corn silage can be a good source of antioxidant compounds which can be used for production of food, cosmetic and pharmaceutical products.
Influence of process parameters and pre-treatments on quality and drying kinetics of apple samples Jokic, S.,J.J. Strossmayer Univ., Osijek (Croatia). Dept. of Process Engineering; Velic, D.,J.J. Strossmayer Univ., Osijek (Croatia). Dept. of Process Engineering; Bilic, M.,J.J. Strossmayer Univ., Osijek (Croatia). Dept. of Process Engineering ...
Czech Journal of Food Sciences,
01/2009, Letnik:
27, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The aim of this research was to determine the influence of the process parameters and pre-treatment methods on the quality and drying kinetics of apple samples of the Florina variety using the ...following standard analytical methods: thermogravimetry, rehydration, colorimetry. The apple samples were dried in a laboratory tray drier at different temperatures (50, 60, and 70 deg C), airflow velocities (1.5 m/s and 2.75 m/s), and pre-treatment methods (dipping in 0.5% ascorbic acid solution; 0.3% L-cysteine solution; 0.1% 4-hexyl resorcinol solution; 0.5% sodium metabisulfite solution; mixed solution of 0.05% 4-hexyl resorcinol and 0.5% sodium metabisulfite; blanching in hot water at 85 deg C). According to the drying time, rehydration and colour characteristics, the optimal drying parameters found were: temperature of 60 deg C and airflow velocity of 2.75 m/s. The drying kinetic equations were estimated using Page's mathematical model. The results of the estimation showed a good agreement with the experimental data. The best results were achieved when the samples were pre-treated with 4-hexyl resorcinol. Blanching in hot water resulted in a higher drying rate and higher rehydration ratio, but also in unacceptable changes in the colour appearance of the apple samples.
Grape seeds are a waste by-product obtained after wine or juice making and present a good source of functional compounds, such as polyphenols. Extraction is a very important step for later use of ...phenolic components. The effect of different temperatures and solid–liquid ratios on the solid–liquid extraction yield of total polyphenols and the effect of four classes of particle size on the extraction kinetics of total polyphenols with 50% of aqueous ethanol were studied. Temperature, solid–liquid ratio and milling degree had positive influence on extraction rate and extent of extraction. The 1.47–6.68% of total polyphenols per dry matter of grape seeds was extracted during 200
min. Extraction kinetics was estimated using non-experimental two-parameter equation – modified Peleg’s model. Results showed a good prediction of Peleg’s model for extraction kinetics in all experiments (
ρ
>
0.994), which gave the possibility for estimation of initial rate and extent of solid–liquid extraction.
The influence of the solvent, temperature, and extraction time on the extractability of total polyphenols from milled soybeans variety Ika was investigated. The study was performed in order to select ...the most suitable solvent (water; 50, 60, 70, and 80% aqueous ethanol) for achieving the highest yield of total polyphenols. The most effective solvent (50% aqueous ethanol solution) was used for monitoring the kinetics and modelling of solid-liquid extraction of total polyphenols from soybeans, average particle size 0.459 mm, at solid-liquid ratio of 20 ml/g (ratio of the solvent volume per g of raw material). The total polyphenols content in the soybean extract was determined spectrophotometrically using Folin-Ciocalteu micro-methods at 765 nm. The applicability of different mathematical models (Peleg, Page, and Logarithmic models) to describe the kinetics of the solid-liquid extraction process of total polyphenols from soybeans was studied as well. The results exhibited a significant influence of the solvent and temperature on the kinetics and extraction yield of total polyphenols from soybeans. The best extraction yield of total polyphenols was obtained using 50% aqueous ethanol solution at 80°C after 120 min (4.322 mg GAE/gdb). The extraction yield of total polyphenols in soybean extracts increased by increasing the extraction temperature and extending the duration of the extraction process. The mathematical models applied showed a good agreement with the experimental results, which allows their application in modelling and optimisation of solid-liquid extraction process for the extraction of total polyphenols from soybeans.
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