Influence of In Vitro Digestion on Antioxidant Activity of Enriched Apple Snacks with Grape Juice.

Fruits are sources of bioactive compounds (BACs), such as polyphenols. This research aimed to study the in vitro bioaccessibility of polyphenols from enriched apple snacks with grape juice and determine their antioxidant capacity. Impregnation (I) treatments were carried out at atmospheric pressure and in a vacuum (IV) at 30, 40, and 50 °C and their combinations with ohmic heating (OH), I/OH, and IV/OH. Later, samples were dehydrated by forced convection at 40, 50, and 60 °C. Enriched samples were subjected to in vitro digestion. The total polyphenols, monomeric polyphenols, and antioxidant activities were determined from recovered extracts. Results showed that total polyphenols present in higher concentrations in the gastric phase, 271.85 ± 7.64 mg GAE/100 g d.m. Monomeric polyphenols' behavior during in vitro digestion for the VI/OH 50 °C and dried treatment (60 °C) was descending, mainly in quercetin, which decreased by 49.38% concerning the initial concentration, before digestion. The cyanin, catechin, epicatechin, and epigallocatechin decreased by 26.66%, 20.71%, 23.38%, and 21.73%, respectively. Therefore, based on obtained results, the IV/OH 50 °C treatment (dried 60 °C) is the best combination to incorporate polyphenols from grape juice.

Starch-Based Aerogels Obtained via Solvent-Induced Gelation.

In this work, the ability of several solvents to induce gel formation from amylomaize starch solubilized in dimethyl sulfoxide (DMSO) was investigated. The formed gels were subjected to solvent exchange using ethanol and dried with supercritical carbon dioxide (sc-CO2) to obtain the aerogels. The influence of starch concentration (3-15 wt%) and solvent content (20-80 wt%) on gel formation was also studied. It was demonstrated that the gelation of starch in binary mixtures of solvents can be rationalized by Hansen Solubility Parameters (HSP) revealing a crucial hole of hydrogen bonding for the gel's strength, which is in agreement with rheological measurements. Only the addition of water or propylene glycol to starch/DMSO solutions resulted in strong gels at a minimum starch and solvent content of 7.5 wt% and 50 wt%, respectively. The resulting aerogels showed comparably high specific surface areas (78-144 m2 g-1) and low envelope densities (0.097-0.203 g cm-3). The results of this work indicate that the HSP parameters could be used as a tool to guide the rational selection of water-free gelation in starch/DMSO systems. In addition, it opens up an attractive opportunity to perform starch gelation in those solvents that are miscible with sc-CO2, avoiding the time-consuming step of solvent exchange.

Covalently Binding of Bovine Serum Albumin to Unsaturated Poly(Globalide-Co-ε-Caprolactone) Nanoparticles by Thiol-Ene Reactions.

When nanoparticles (NPs) are introduced to a biological fluid, different proteins (and other biomolecules) rapidly get adsorbed onto their surface, forming a protein corona capable of giving to the NPs a new "identity" and determine their biological fate. Protein-nanoparticle conjugation can be used in order to promote specific interactions between living systems and nanocarriers. Non-covalent conjugates are less stable and more susceptible to desorption in biological media, which makes the development of engineered nanoparticle surfaces by covalent attachment an interesting topic. In this work, the surface of poly(globalide-co-ε-caprolactone) (PGlCL) nanoparticles containing double bonds in the main polymer chain is covalently functionalized with bovine serum albumin (BSA) by thiol-ene chemistry, producing conjugates which are resistant to dissociation. The successful formation of the covalent conjugates is confirmed by flow cytometry (FC) and fluorescence correlation spectroscopy (FCS). Transmission electron microscopy (TEM) allows the visualization of the conjugate formation, and the presence of a protein layer surrounding the NPs can be observed. After conjugation with BSA, NPs present reduced cell uptake by HeLa and macrophage RAW264.7 cells, in comparison to uncoated NP. These results demonstrate that it is possible to produce stable conjugates by covalently binding BSA to PGlCL NP through thiol-ene reaction.

Valorization of papaya (Carica papaya L.) agroindustrial waste through the recovery of phenolic antioxidants by supercritical fluid extraction.

In this work, supercritical fluid extraction (SFE) for the recovery of phenolic antioxidants from papaya agroindustrial waste (seeds) was explored, making use of neat supercritical CO2 and CO2 added with ethanol (CO2-EtOH). A full factorial design played on in order to evaluate the effect of CO2 extraction parameters (temperature between 40 and 60 °C, and pressure between 10 and 30 MPa) on yield and total phenols content (TPC), then ethanol was applied as a co-solvent and its effect on the recovery of phenolics was analyzed. The SFE was compared to the conventional extraction using ethanol. The antioxidant activity of all extracts was evaluated, and the phenolic composition in selected extracts was assessed by HPLC-ESI-MS. The highest extraction yields (21.02-26.46%) and TPC (15.34-34.23 mgGAE/g) were found in extracts obtained with CO2-EtOH and ethanol. Good and selective phenolic recovery was obtained by using CO2-EtOH, (44.81% of TPC recovered). The CO2-EtOH extracts showed high radical scavenging activity and higher antioxidant effect against lipid oxidation. Some phenolic acids and flavonoids were observed in the extracts with better antioxidants properties. The results showed that SFE is a suitable green technology for the phenolic recovery from papaya agroindustrial waste, and also an alternative for its valorization.

CDK2 and Bcl-xL inhibitory mechanisms by docking simulations and anti-tumor activity from piperine enriched supercritical extract.

Supercritical fluid technologies offer an innovative method for food industry and drug discovery from natural sources. The aim of the study is to investigate the anti-tumor activity of piperine rich extract by supercritical fluid (SFE) from black pepper (Piper nigrum). In silico docking simulations predicted anti-tumor molecular mechanism and protein-piperine hydrophobic interactions, showing hydrogen bonds between piperine and residue Ser5 inside the ATP binding site in CDK2. Moreover, piperine interacts with peptide substrate residue Lys8 inside its binding site in Cyclin A molecule. Other predicted interaction showed piperine inside the hydrophobic groove of Bcl-xL. Confirming the docking simulation, in vitro assays with SFE (40 °C/30 MPa) showed cytotoxicity to MCF-7 cells (IC50 = 27.8 ±â€¯6.8 µg/ml) correlated to increased apoptosis. Balb/c mice-bearing Ehrlich Ascites Carcinoma (EAC) group that received the SFE (100 mg/kg/day) showed tumor growth inhibition (60%) and increased mice survival (50%), probably related to cell cycle arrest (G2/M) and increased apoptosis. In vivo treatments with SFE increased the expression of pro-apoptotic proteins (p53 and Bax), inhibited cell cycle proteins (CDK2, Cyclin A) and anti-apoptotic protein (Bcl-xL). Thus, confirming in silico predicted inhibitory interactions. These results clearly showed promising performance of the piperine-rich fraction recovered from black pepper, drawing attention to its use as complementary therapy for cancer.

N-acetylcysteine side-chain functionalization of poly(globalide-co-ε-caprolactone) through thiol-ene reaction.

N-Acetylcysteine (NAC) is a drug well known for its antimucolytic action, antioxidant activity and ability to protect cells from oxidative stress. Conjugation of NAC with double bonds in the main polymer chain of poly(globalide-co-ε-caprolactone) (PGlCL) through thiol-ene reaction is reported. Different globalide (Gl) (an unsaturated macrolactone) to ε-caprolactone (CL) ratios were employed for PGlCL synthesis. The polymeric materials (PGlCL-NAC) were evaluated in terms of the number of functionalized double bonds, thermal properties, affinity for water and antioxidant potential. PGlCL-NAC containing more globalide repeating units presented higher degree of functionalization, due to the higher number of double bonds available to react through thiol-ene coupling. For high globalide contents (Gl/CL ratios above 50/50), NAC coupling in PGlCL chains resulted in completely amorphous copolymers with a more hydrophilic character, which should enhance bioresorption and cell adhesion characteristics. Functionalization also gave rise to a thioether linkage, conferring to PGlCL-NAC an antioxidant character, important for biomedical applications, where the material could combat cellular oxidative-stress.

In vivo antitumor activity of by-products of Passiflora edulis f. flavicarpa Deg. Rich in medium and long chain fatty acids evaluated through oxidative stress markers, cell cycle arrest and apoptosis induction.

Antiinflammatory and antitumor activity has been reported in Passiflora edulis (yellow passion fruit) nevertheless the intrinsic mechanisms of action are not fully elucidated. The present study aimeds to perform a comparison between the antitumor activity involving the crude extract (HCE) and the supercritical fluid extract with ethanol as co-solvent (SFEtOH) from P. edulis f. flavicarpa Deg. The in vitro cytotoxicity was evaluated in MCF-7 cells, while the in vivo antitumor activity was assessed in male Balb/c mice inoculated with Ehrlich carcinoma cells. SFEtOH exhibited higher antitumor activity compared to HCE. Wherein, SFEtOH showed an EC50 of 264.6 µg/mL against MCF-7 cells as well as an increased inhibition of tumor growth of 48.5% (p < 0.001) in male Balb/c mice, thereby promoting an increased mice lifespan to approximately 42%. Moreover, SFEtOH caused lipid (p < 0.001) and protein (p < 0.001) oxidation by increasing glutathione redox cycle activity while decreased the thioredoxin reductase activity (p < 0.001). SFEtOH also induced oxidative DNA damage in Ehrlich ascites carcinoma (EAC) cells leading to G2/M cycle arrest and has increased apoptotic cells up to 48.2%. These data suggest that the probable mechanisms of antitumor effect are associated to the lipid, protein and DNA damage, leading to cell cycle arrest and triggering apoptosis via mitochondrial pathway, should be probable due to the presence of medium and long chain fatty acids such as lauric acid.

Technological process for cell disruption, extraction and encapsulation of astaxanthin from Haematococcus pluvialis.

In this work, the effectiveness of different enzymatic techniques for cell wall disruption of Haematococcus pluvialis for the extraction of carotenoids and subsequent encapsulation of extracts in the co-polymer poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) using the Solution Enhanced Dispersion by Supercritical fluids (SEDS) technique was investigated. Glucanex(®) performed best compared with Lyticase(®) and Driselase(®). The conditions for enzymatic lysis using this enzyme preparation were established as a pH of 4.5, a temperature of 55 °C, an initial activity of ß-1,3-glucanase of 0.6 U mL(-1) and a reaction time of 30 min. Enzymatic lysis assisted by ultrasound without biomass freezing was shown to be a promising and simple one-step technique for cell wall disruption, reaching 83.90% extractability. In the co-precipitation experiments, the highest encapsulation efficiency (51.21%) was obtained when using a higher biomass to dichloromethane ratio (10 mg mL(-1)) at the carotenoid extraction step and a lower pressure of precipitation (80 bar). In these conditions, spherical particles in the micrometer range (0.228 µm) were obtained.

Antimicrobial activity and composition profile of grape (Vitis vinifera) pomace extracts obtained by supercritical fluids.

The possibility of increasing the aggregated value of the huge amount of residues generated by wineries around the world foment studies using the grape pomace - the residue from the wine production, composed by seed, skin and stems - to obtain functional ingredients. Nowadays, consumers in general prefer natural and safe products mainly for food and cosmetic fields, where the supercritical fluid extraction is of great importance due to the purity of the extracts provided. Therefore, the objective of this work is to evaluate the global extraction yield, the antimicrobial activity and the composition profile of Merlot and Syrah grape pomace extracts obtained by supercritical CO2 (SC-CO2) and CO2 added with co-solvent at pressures up to 300 bar and temperatures of 50 and 60 °C. The results were compared with the ones obtained by Soxhlet and by ultrasound-assisted leaching extraction methods. The main components from the extracts, identified by HPLC, were gallic acid, p-OH-benzoic acid, vanillic acid and epicatechin. The antibacterial and antifungal activities of the extracts were evaluated using four strains of bacteria (Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa) and three fungi strains (Candida albicans, Candida parapsilosis, Candida krusei). Despite lower extraction yield results, the supercritical fluid extracts presented the highest antimicrobial effectiveness compared to the other grape pomace extracts due to the presence of antimicrobial active compounds. Syrah extracts were less efficient against the microorganisms tested and Merlot extracts were more active against Gram-positive bacteria.

Supercritical fluid extraction from spent coffee grounds and coffee husks: antioxidant activity and effect of operational variables on extract composition.

The present study describes the chemical composition and the antioxidant activity of spent coffee grounds and coffee husks extracts, obtained by supercritical fluid extraction (SFE) with CO(2) and with CO(2) and co-solvent. In order to evaluate the high pressure method in terms of process yield, extract composition and antioxidant activity, low pressure methods, such as ultrasound (UE) and soxhlet (SOX) with different organic solvents, were also applied to obtain the extracts. The conditions for the SFE were: temperatures of 313.15K, 323.15K and 333.15K and pressures from 100 bar to 300 bar. The SFE kinetics and the mathematical modeling of the overall extraction curves (OEC) were also investigated. The extracts obtained by LPE (low pressure extraction) with ethanol showed the best results for the global extraction yield (X(0)) when compared to SFE results. The best extraction yield was 15±2% for spent coffee grounds with ethanol and 3.1±04% for coffee husks. The antioxidant potential was evaluated by DPPH method, ABTS method and Folin-Ciocalteau method. The best antioxidant activity was showed by coffee husk extracts obtained by LPE. The quantification and the identification of the extracts were accomplished using HPLC analysis. The main compounds identified were caffeine and chlorogenic acid for the supercritical extracts from coffee husks.