Extraction of High Value Products from Zingiber officinale Roscoe (Ginger) and Utilization of Residual Biomass.

Zingiber officinale Roscoe (ginger) is a plant from the Zingiberaceae family, and its extracts have been found to contain several compounds with beneficial bioactivities. Nowadays, the use of environmentally friendly and sustainable extraction methods has attracted considerable interest. The main objective of this study was to evaluate subcritical propane (scPropane), supercritical CO2 (scCO2), and supercritical CO2 with ethanol (scCO2 + EtOH) as co-solvent methods for the extraction of high value products from ginger. In addition, the reuse/recycling of the secondary biomass in a second extraction as a part of the circular economy was evaluated. Both the primary and the secondary biomass led to high yield percentages, ranging from 1.23% to 6.42%. The highest yield was observed in the scCO2 + EtOH, with biomass prior used to scCO2 extraction. All extracts presented with high similarities as far as their total phenolic contents, antioxidant capacity, and chemical composition. The most abundant compounds, identified by the two different gas chromatography-mass spectrometry (GC-MS) systems present, were a-zingiberene, ß- sesquiphellandrene, a-farnesene, ß-bisabolene, zingerone, gingerol, a-curcumene, and γ-muurolene. Interestingly, the reuse/recycling of the secondary biomass was found to be promising, as the extracts showed high antioxidant capacity and consisted of significant amounts of compounds with beneficial properties.

Liquid-Liquid Equilibrium of Sesame Fatty Acid (Ethyl and Methyl) Ester + Glycerol + Ethanol/Methanol Mixtures at Different Temperatures.

This study aimed to investigate the liquid-liquid equilibrium (LLE) behavior of sesame fatty acid ethyl ester (FAEE) and methyl ester (FAME) in combination with glycerol and the co-solvents ethanol and methanol. FAEE and FAME were produced through the transesterification of mechanically extracted and purified sesame oil, using potassium hydroxide (KOH) as a homogeneous base catalyst. The reactions were conducted in ethanol and methanol to produce FAEE and FAME, respectively. Post-reaction, the products were separated and purified, followed by an analysis of the LLE behavior at 313.15 K and 323.15 K under atmospheric pressure (101.3 kPa). The experimental process for the miscibility analysis utilized a jacketed glass cell adapted for this study. Miscibility limits or binodal curves were determined using the turbidity-point method. Tie lines were constructed by preparing mixtures of known concentrations within the two-phase region, which allowed the phases to separate after agitation. Samples from both phases were analyzed to determine their composition. This study revealed that higher temperatures promoted greater phase separation and enhanced the biodiesel purification process. The NRTL model effectively correlated the activity coefficients with the experimental data, showing good agreement, with a root-mean-square deviation of 3.5%. Additionally, the data quality was validated using Marcilla's method, which yielded an R2 value close to 1. Attraction factors and distribution coefficients were also calculated to evaluate the efficiency of the co-solvents as extraction agents. The findings indicated higher selectivity for methanol than for ethanol, with varying degrees of distribution among the co-solvents. These results offer significant insights into enhancing biodiesel production processes by considering the effects of co-solvents on the LLE properties of mixtures, ultimately contributing to more efficient and cost-effective biodiesel production.

A Network of Processes for Biorefining Burdock Seeds and Roots.

In this work, a novel sustainable approach was proposed for the integral valorisation of Arctium lappa (burdock) seeds and roots. Firstly, a preliminary recovery of bioactive compounds, including unsaturated fatty acids, was performed. Then, simple sugars (i.e., fructose and sucrose) and phenolic compounds were extracted by using compressed fluids (supercritical CO2 and propane). Consequently, a complete characterisation of raw biomass and extraction residues was carried out to determine the starting chemical composition in terms of residual lipids, proteins, hemicellulose, cellulose, lignin, and ash content. Subsequently, three alternative ways to utilise extraction residues were proposed and successfully tested: (i) enzymatic hydrolysis operated by Cellulases (Thricoderma resei) of raw and residual biomass to glucose, (ii) direct ethanolysis to produce ethyl levulinate; and (iii) pyrolysis to obtain biochar to be used as supports for the synthesis of sulfonated magnetic iron-carbon catalysts (Fe-SMCC) to be applied in the dehydration of fructose for the synthesis of 5-hydroxymethylfurfural (5-HMF). The development of these advanced approaches enabled the full utilisation of this resource through the production of fine chemicals and value-added compounds in line with the principles of the circular economy.

Phytochemicals and Biological Activities of Burdock (Arctium lappa L.) Extracts: A Review.

Arctium lappa L., also known as burdock, is an edible wild plant which has the ability to grow in distinct environments and is considered a weed in several parts of the world. This species has great value in the biological and medical fields with its major secondary components being phenolic compounds and terpenes, substances rich in desired biological activities as antioxidant, antimicrobial, antitumor and anti-inflammatory. In addition, burdock leaves extracts have shown a modulatory effect on the complement system, which plays an important role in the development of inflammatory diseases, with an inhibitory effect on all complement pathways. Thus, natural products with those relevant activities are promising agents for healthcare applications. Therefore, the species A. lappa may represent an interesting asset for researching and developing new therapies for inflammatory afflictions.

Performing under pressure: esterification activity of dry fermented solids in subcritical and supercritical CO2.

OBJECTIVE: Lipases are often used in immobilized form, but commercial immobilized lipases are costly. An alternative is to produce lipases in solid-state fermentation, dry the solids and then use the "dry fermented solids" (DFS) directly. We produced DFS by growing Burkholderia contaminans on a mixture of sugarcane bagasse and sunflower seed meal and used the DFS to esterify oleic acid with ethanol in subcritical and supercritical CO2 at 40 °C. RESULTS: Compared to a control without CO2 at atmospheric pressure, subcritical CO2 at 30 bar improved esterification activity 1.2-fold. Higher pressures, including supercritical pressures up to 150 bar, reduced activity to less than 80% of the control. At 30 bar, the esterification activity was improved a further 1.8-fold with the addition of 9% water (i.e. 9 g water per 100 g oleic acid) to the reaction medium. CONCLUSION: A subcritical CO2 atmosphere, with the addition of a small amount of water, improved the esterification activity of DFS containing lipases of Burkholderia contaminans.

Inhibitory Effect of Supercritical Extracts from Arctium lappa L. on the Lectin Pathway of the Complement System.

The complement system participates in host defense by eliminating microorganisms and triggering inflammation. However, insufficient control or exacerbated complement activation contributes to inflammatory diseases. Since promising antioxidant and anti-inflammatory activities have been identified in Arctium lappa L. extracts, this study aims to explore the effect of A. lappa extracts on the lectin pathway (LP) of complement activation. Four extracts were obtained by supercritical extraction using scCO2 with or without ethanol as co-solvent, at different temperatures and pressures (E1: 2.2 mg/mL, E2: 2.6 mg/mL and E3: 2.0 mg/mL, E4: 1.5 mg/mL). To evaluate the effect of A. lappa extracts on the LP activation, an ELISA assay using mannose binding lectin pathway of complement was carried out with C4 detection. All extracts showed a concentration-dependent inhibitory effect on the activation of complement by the LP. The following IC50 were observed for E1, E2, E3 and E4: 179.4 µg/mL, 74.69 µg/mL, 119.1 µg/mL and 72.19 µg/mL, respectively. Our results suggest that A. lappa extracts are potential candidates for the treatment of inflammatory disorders that are complement-related.

High pressure extraction of olive leaves (Olea europaea): bioactive compounds, bioactivity and kinetic modelling.

In this study, the extraction yield, the mathematical modeling of pressurized liquid extraction (PLE) kinetics with sub- and supercritical carbon dioxide (SC-CO2) of olive leaves (Olea europaea) and the biological activity of the extracts were evaluated. The extraction with PLE was conducted isobarically (10.3 MPa), varying the temperature (20, 40 and 60 °C) and the solvent (ethyl acetate, acetone, ethanol, ethanol:water-80:20, v:v), solvent flow (2 mL min-1) and time (110 min) and the extractions with SC-CO2, varying the temperature between 20 and 60 °C and the pressure between 8 and 25 MPa, keeping the time constant (210 min) and the CO2 flow of 2 mL min-1. In the extracts, antioxidant activity, total phenolic and flavonoid contents and oleuropein were evaluated. The highest total extract yield in the PLE was 30.91% at 60 °C, 10.3 MPa using ethanol:water (80:20, v:v). The yield obtained using the supercritical fluid was 0.68% at 60 °C and 25 MPa. The PLE extract obtained with ethanol at 60 °C presented the highest concentration of total phenolic content (386.42 mg GAE g-1 extract), total flavonoids content (33.43 mg CAT g-1 extract), oleuropein (73.65 mg g-1 extract) and antioxidant activity (82.87%). The overall extraction curves were modeled using the well-established Sovová model and kinetic extraction model based on the Brunauer-Emmett-Teller theory of adsorption. Both kinetic models used were able to correlate well with the experimental data with slightly better results obtained by the former. The alternative PLE extraction technique investigated in this work was found to be suitable for the extraction of olive leaves after short times of extraction obtaining an extract with high biological activities.

Effect of grilling and baking on physicochemical and textural properties of tilapia (Oreochromis niloticus) fish burger.

The influence of two common cooking methods, grilling and baking, on chemical composition, water retention, fat retention, cooking yield, diameter reduction, expressible water, color and mechanical texture of tilapia (Oreochromis niloticus) fish burgers was investigated. Texture analyses were performed using a Warner-Bratzler test. The fish burger had a softer texture with a lower shear force than other meat products reported in the literature. There were no significant differences in proximate composition, diameter reduction, fat retention and expressible water between the grilled and oven-baked fish burgers. Cooking methods did not affect the cooking times and cooking rates. Warner-Bratzler parameters and color were significantly influenced by the cooking method. Grilling contributed to a shear force and work of shearing increase due to the lower cooking yield and water retention. Raw burgers had the highest L* (69.13 ± 0.96) and lowest b* (17.50 ± 0.75) values. Results indicated that baking yielded a product with better cooking characteristics, such as a desired softer texture with lower shear values (4.01 ± 0.54) and increased water retention (95.82 ± 0.77). Additionally, the baked fish burgers were lighter (higher L*) and less red (lower a*) than the grilled ones.

Ethanol organosolv pretreatment of sugarcane bagasse assisted by organic acids and supercritical carbon dioxide.

The scCO2-assisted organosolv pretreatment of sugarcane bagasse was carried out using aqueous ethanol and organic acid catalysts. Variables involved were temperature (150-190 °C), time (0-60 min), type of catalyst (acetic, citric, and oxalic acids), amount of CO2 (25-50 g), ethanol titer in water (0-80 vol%), and catalyst concentration (0.5 to 1.5 % w·v-1). The best delignification (86 wt%) and glucan retention (89 wt%) were achieved at 170 °C for 15 min using 60 vol% ethanol in water, 1 wt% oxalic acid, and 25 g CO2. Organic acid esterification was a limitation for pretreatment operations using ethanol titers above 60 vol%. Enzymatic hydrolysis of pretreated materials at 1 % (w·v-1) glucans released 74.3 ± 0.2 % glucose in 96 h using Cellic CTec3 (Novozymes) at 9.89 FPU·gglucans-1. The concentrated pretreatment liquor allowed lignin recovery by water precipitation in high yields, while the aqueous supernatant contained low levels of fermentation inhibitors.

Investigation of the Genotoxic, Antigenotoxic and Antioxidant Profile of Different Extracts from Equisetum arvense L.

The present study investigated the cyto-genotoxic and antigenotoxic effects of four different extracts of Equisetum arvense L. (common name: field horsetail) on human lymphocytes. Specifically, Soxhlet's prepared extracts from E. arvense L., using different solvents (S1: methanol (MeOH)-, S2: ethanol (EtOH)-, S3: water-, and S4: ethanol/water (EtOH-W)-) were analyzed for (a) their total phenolic and flavonoid content (TPC and TFC, respectively), (b) their antioxidant activity (AA), via the DPPH, FRAP and ABTS assays, and (c) their cyto-genotoxic and/or protective efficiency against the mutagenic agent mitomycin C, via the Cytokinesis Block MicroNucleus assay. All extracts showed increased TPC, TFC, and AA values in almost all cases. S1, S3 and S4 demonstrated no cytotoxic potential, whereas S2 was cytotoxic only at the highest concentrations. Genotoxicity was not observed in the tested extracts. The highest antigenotoxic activity was observed for EtOH-W (S4) extract, which was found to be rich in flavonoids, flavonoid-O-glycosides, phytosterols, phenolic and fatty acids as well as in minerals and mainly in K, Ca, Mg, Si and P, as assessed by using various mass spectrometry techniques. Those findings confirm that E. arvense L. extracts could be valuable candidates for medicinal applications and pharmaceutical products, thus alleviating the effects of more conventional drugs.

Enhancing the Recovery of Bioactive Compounds of Soybean Fermented with Rhizopus oligosporus Using Supercritical CO2: Antioxidant, Anti-Inflammatory, and Oxidative Proprieties of the Resulting Extract.

The aim of the present study was to evaluate the use of supercritical CO2 combined with cosolvent for the recovery of bioactive compounds of soybean fermented with Rhizopus oligosporus NRRL 2710. Soxhlet extractions using seven different organic solvents (n-hexane, petroleum ether, ethyl acetate, acetone, ethanol, methanol, and water) were initially performed for comparative purposes. The extracts obtained were characterized by physicochemical, antioxidant, total phenolic, and oxidative proprieties. For the Soxhlet extractions, the highest and lowest yields obtained were 45.24% and 15.56%, using methanol and hexane, respectively. The extraction using supercritical CO2 combined with ethanol as a static modifier (scCO2 + EtOH) presented, at a high pressure (25 MPa) and temperature (80 °C), a phenolic compound content of 1391.9 µg GAE g-1 and scavenging of 0.17 g, reaching a 42.87% yield. The extracts obtained by sCO2 + EtOH were characterized by high contents of essential fatty acids (linoleic acid and oleic acid) and bioactive compounds (gallic acid, trans-cinnamic acid, daidzein, and genistein). These extracts also showed a great potential for inhibiting hyaluronidase enzymes (i.e., anti-inflammatory activity). Thermogravimetric analyses of the samples showed similar profiles, with oil degradation values in the range from 145 to 540 °C, indicating progressive oil decomposition with a mass loss ranging from 93 to 98.7%. In summary, this study demonstrated the flexibility of scCO2 + EtOH as a green technology that can be used to obtain high-value-added products from fermented soybean.

Catalytic oxidation of concentrated orange oil phase by synthetic metallic complexes biomimetic to MMO enzyme.

BACKGROUND: This paper reports the catalytic oxidation of the concentrated orange oil phase using the complexes [Fe(III)(BMPP)Cl(micro-O)Fe(III)Cl(3)], [Cu(II)(BTMEA)(2)Cl]Cl and [Co(II)(BMPP)]Cl(2) biomimetic to methane monooxygenase enzyme as catalysts and hydrogen peroxide as oxidant. RESULTS: The reaction products of oil oxidation, mainly nootkatone, were identified by gas chromatography/mass spectrometry. A screening of catalysts was performed through a full 2(3) experimental design, varying the temperature from 30 to 70 degrees C, the catalyst concentration from 7.0 x 10(-4) to 1.5 x 10(-3) mol L(-1) and the oxidant/substrate molar ratio from 1:1 to 3:1. The results of reaction kinetics employing the most promising catalysts showed that conversions to nootkatone of up to 8% were achieved after 16 h at 70 degrees C. CONCLUSION: The results obtained in this study in terms of nootkatone production should be considered encouraging, since a real, industrially collected, raw material, instead of pure valencene, was employed in the reaction experiments, with a final content about ten times that present in the original concentrated oil.

Supercritical Fluids: A Promising Technique for Biomass Pretreatment and Fractionation.

Lignocellulosic biomasses are primarily composed of cellulose, hemicelluloses and lignin and these biopolymers are bonded together in a heterogeneous matrix that is highly recalcitrant to chemical or biological conversion processes. Thus, an efficient pretreatment technique must be selected and applied to this type of biomass in order to facilitate its utilization in biorefineries. Classical pretreatment methods tend to operate under severe conditions, leading to sugar losses by dehydration and to the release of inhibitory compounds such as furfural (2-furaldehyde), 5-hydroxy-2-methylfurfural (5-HMF), and organic acids. By contrast, supercritical fluids can pretreat lignocellulosic materials under relatively mild pretreatment conditions, resulting in high sugar yields, low production of fermentation inhibitors and high susceptibilities to enzymatic hydrolysis while reducing the consumption of chemicals, including solvents, reagents, and catalysts. This work presents a review of biomass pretreatment technologies, aiming to deliver a state-of-art compilation of methods and results with emphasis on supercritical processes.

Effects of pressurized hot water extraction on the yield and chemical characterization of pectins from Campomanesia xanthocarpa Berg fruits.

Pressurized hot water extraction (PHWE), known as a "green" extraction technique, was used to obtain polysaccharide from the pulp of gabiroba (Campomanesia xanthocarpa Berg) fruits. The effects of pressure, temperature, and flow rate on pectin yields were analyzed through a full factorial design experiment 23. The optimal extraction conditions to achieve maximum pectin yield (5.70 wt%) were pressure of 150 bar, temperature of 120 °C, and flow rate of 1.5 mL min-1. The high pressure (100 bar) promoted an increase in galacturonic acid content (36.0%) compared to conventional hot water extraction (CEGP) with 25.7%. Differences in the proportion of homogalacturonan (HG) and rhamnogalacturonan (RG-I) domains ranging from 16.3 to 35.4% and 61.7 to 80.1%, respectively, were observed for each pectin sample according to the extraction conditions. The mono-dimensional (13C-NMR) and bi-dimensional (1H/13C HSQC-NMR) analyses confirmed the presence of HG and RG-I regions and indicated the presence of arabinogalactans type I (AG-I) and arabinogalactans type II (AG-II) in the PHWE pectin samples, which was not found for pectins from gabiroba pulp obtained by CEGP. The results showed that PHWE proved to be a promising method for extracting pectins from gabiroba fruits.

Inulinase production in a batch bioreactor using agroindustrial residues as the substrate: experimental data and modeling.

The production of inulinase employing agroindustrial residues as the substrate is a good alternative to reduce production costs and to minimize the environmental impact of disposing these residues in the environment. This study focused on the use of a phenomenological model and an artificial neural network (ANN) to simulate the inulinase production during the batch cultivation of the yeast Kluyveromyces marxianus NRRL Y-7571, employing a medium containing agroindustrial residues such as molasses, corn steep liquor and yeast extract. It was concluded that due to the complexity of the medium composition it was rather difficult to use a phenomenological model with sufficient accuracy. For this reason, an alternative and more cost-effective methodology based on ANN was adopted. The predictive capacity of the ANN was superior to that of the phenomenological model, indicating that the neural network approach could be used as an alternative in the predictive modeling of complex batch cultivations.

Supercritical carbon dioxide combined with 1-butyl-3-methylimidazolium acetate and ethanol for the pretreatment and enzymatic hydrolysis of sugarcane bagasse.

The use of green solvents for the partial delignification of milled sugarcane bagasse (1mm particle size) and for the enhancement of its susceptibility to enzymatic hydrolysis was demonstrated. The experiments were carried out for 2h using 40 g of supercritical carbon dioxide combined with 1-butyl-3-methylimidazolium acetate and 15.8 g of ethanol. The effects of temperature (110-180 °C), pressure (195-250 bar) and IL-to-bagasse mass ratio (0:1-1:1) were investigated through a factorial design in which the response variables were the extent of delignification and both anhydroglucose and anhydroxylose contents in the pretreated materials. The highest delignification degree (41%) led to the best substrate for hydrolysis, giving a 70.7 wt% glucose yield after 12h using 5 wt% and Cellic CTec2® (Novozymes) at 10 mg g(-1) total solids. Hence, excellent substrates for hydrolysis were produced with a minimal IL requirement, which could be recovered by ethanol washing for its downstream processing and reuse.

Influence of two different alcohols in the esterification of fatty acids over layered zinc stearate/palmitate.

In this work, esterification of fatty acids (oleic, linoleic and stearic acid) with a commercial zinc carboxylate (a layered compound formed by simultaneous intercalation of stearate and palmitate anions) was performed. Kinetic modeling using a quasi-homogeneous approach successfully fitted experimental data at different molar ratio of fatty acids/alcohols (1-butanol and 1-hexanol) and temperature. An apparent first-order reaction related to all reactants was found and activation energy of 66 kJ/mol was reported. The catalyst showed to be unique, as it can be easily recovered like a heterogeneous catalysts behaving like ionic liquids. In addition, this catalyst demonstrated a peculiar behavior, because higher reactivity was observed with the increase in the alcohols chain length compared to the authors' previous work using ethanol.

Kinetics of enzymatic hydrolysis of olive oil in batch and fed-batch systems.

This work reports experimental data, kinetic modeling, and simulations of enzyme-catalyzed hydrolysis of olive oil. This reaction was performed in batch system and an ordered-sequential Bi Bi model was used to model the kinetic mechanism. A fed-batch system was proposed and experimental data were obtained and compared to the simulated values. The kinetic model used was able to correlate the experimental data, in which a satisfactory agreement between the experimental data and modeling results was obtained under different enzyme concentration and initial free water content. Therefore, the modeling allowed a better understanding of the reaction kinetics and affords a fed-batch simulation for this system. From the results obtained, it was observed that the fed-batch approach showed to be more advantageous when compared to the conventional batch system.

Kinetics of enzyme-catalyzed hydrolysis of steam-exploded sugarcane bagasse.

This work presents the experimental kinetic data and the fractal modeling of sugarcane bagasse steam treatment and enzymatic hydrolysis. Sugarcane bagasse (50 wt% moisture) was pretreated by autohydrolysis at 210 °C for 4 min. Acid catalysis involved the use of 9.5mg g(-1) of H2SO4 or H3PO4 in relation to the substrate dry mass at these same pretreatment conditions. Unwashed, water-washed and alkali-washed substrates were hydrolyzed at 2.0 wt% using 8 and 15 FPU g(-1) (108.22 and 199.54 mg/g) total solids of a Celluclast 1.5 L and Novozym 188 mixture (Novozymes). The fractal kinetic modeling was used to describe the effect of pretreatment and both washing processes on substrate accessibility. Water and/or alkali washing was not strictly necessary to achieve high hydrolysis efficiencies. Also, the fractal model coefficients revealed that H3PO4 was a better pretreatment catalyst under the experimental conditions used in this study, resulting in the most susceptible substrates for enzymatic hydrolysis.

Kinetics of ultrasound-assisted lipase-catalyzed glycerolysis of olive oil in solvent-free system.

This work reports experimental kinetic data of solvent-free glycerolysis of olive oil using a commercial immobilized lipase (Novozym 435) under the influence of ultrasound irradiation. The experiments were performed in a mechanically stirred reactor under ultrasound irradiation, evaluating the effects of temperature (50-70 °C), enzyme concentration (2.5-10 wt%) and glycerol to oil molar ratio (0.8:1-3:1). Results show that ultrasound-assisted lipase-catalyzed glycerolysis might be a potential alternative route to conventional methods, as high contents of reaction products, especially monoglycerides, were achieved at mild irradiation power supply (~130 W) and temperature, in a relatively short reaction time (2h) and low enzyme content (7.5 wt%). To completeness, two simplified kinetic modeling approaches, based on the ordered-sequential bi bi mechanism and reaction stoichiometry, were employed to represent the experimental data, thus allowing a better understanding of the reaction kinetics.