Antioxidant and antimicrobial evaluation of rice bran (Oryza sativa L.) extracts in a mayonnaise-type emulsion.

The objective of this study was to evaluate the in vitro antimicrobial and antioxidant activities of different bran extracts and concentrations, and their influence on the parameters of a mayonnaise-type emulsion. To that end, first ethanol and then water were used to extract two rice bran extracts (RBE) from rice bran. Both these extracts were then added at two different concentrations (0.5 and 2%) to the emulsions that were subsequently analysed after seven days under two different storage temperatures, 4 °C and 20 °C. The antioxidant and antimicrobial ability of the extracts were evaluated, along with a control and a synthetic antioxidant. Results indicate the positive effect of rice bran extracts as additives in the food matrix. Ethanolic rice bran extract (EE) at 2% decreased the oxidation as well as mould and yeast proliferation and preserved the emulsion structure, while the other treatments acted in a similar way although their effect was less pronounced.

Fixed-bed performance of a waste-derived granular activated carbon for the removal of micropollutants from municipal wastewater.

This work aimed to assess the fixed-bed adsorptive performance of a primary paper mill sludge-based granular activated carbon (PSA-PA) for the removal of pharmaceuticals, namely carbamazepine (CBZ), sulfamethoxazole (SMX) and paroxetine (PAR), from water. The breakthrough curves corresponding to the adsorption of CBZ at different flow rates and in two different matrices (distilled and municipal wastewater) were firstly determined, which allowed to select the most favorable flow rate for the subsequent experiments. The fixed-bed adsorption of CBZ, SMX and PAR from single and ternary solutions in wastewater showed that the performance of PSA-PA was different for each pharmaceutical. According to the obtained breakthrough curves, the poorest bed adsorption capacity, either from single or ternary solution, was observed for SMX, which may be related with electrostatic repulsion at the pH of the wastewater used (pH ~ 7.3-7.7). Also, the bed adsorption capacity of PSA-PA for SMX, in the ternary solution, was notoriously lower compared to the single solution, while it slightly decreased for CBZ and even increased for PAR. The regeneration studies showed that the CBZ adsorption capacity of the PSA-PA bed decreased about 38 and 71% after the first and the second thermal regeneration stages, respectively. This decline was comparatively larger than the corresponding reduction of the PSA-PA specific surface area (SBET), which decreased only 5 and 25% for the first and second regeneration stages, respectively, and pointed to the lack of viability of more than one regeneration stage.

Obtaining granular activated carbon from paper mill sludge - A challenge for application in the removal of pharmaceuticals from wastewater.

In this work, a granular activated carbon (GAC) was produced using primary paper mill sludge (PS) as raw material and ammonium lignosulfonate (AL) as binder agent. PS is a residue from the pulp and paper industry and AL is a by-product of the cellulose pulp manufacture and the proposed production scheme contributes for their valorisation together with important savings in GAC precursors. The produced GAC (named PSA-PA) and a commercially available GAC (GACN), used as reference material, were physically and chemically characterized. Then, these materials were tested in batch experiments for the adsorption of carbamazepine (CBZ), sulfamethoxazole (SMX), and paroxetine (PAR) from ultra-pure water and wastewater. Even though GACN and PSA-PA possess very similar specific surface areas (SBET) (629 and 671 m2 g-1, respectively), PSA-PA displayed lower maximum adsorption capacities (qm) than GACN for the pharmaceuticals here studied (6 ±â€¯1-44 ±â€¯5 mg g-1 and 49 ±â€¯6-106 ±â€¯40 mg g-1, respectively). This may be related to the comparatively higher incidence of mesopores in GACN, which might have positively influenced its adsorptive performance. Moreover, the highest hydrophobic character and degree of aromaticity of GACN could also have contributed to its adsorption capacity. On the other hand, the performance of both GACs was significantly affected by the matrix in the case of CBZ and SMX, with lower qm in wastewater than in ultra-pure water. However, the adsorption of PAR was not affected by the matrix. Electrostatic interactions and pH effects might also have influenced the adsorption of the pharmaceutical compounds in wastewater.

Bioavailability, composition and functional characterization of extracts from Oryza sativa L. bran.

The aim of this study has been to assess the composition and antioxidant activities of rice bran extracts submitted to a human simulated digestion, which extraction process was previously optimized. In order to adjust the optimum values for the extraction, D-optimal experimental design and response surface methodology have been applied. Phenolic compounds and γ-oryzanol contents have been used as response parameters. In this way, two different extracts have been obtained. The first one, was obtained with 100% water as solvent, and it was mainly composed by phenolic acids. Ferulic acid was the majority compound found with a concentration of 1.00 ±â€¯0.03 mg/g extract, followed by p-coumaric acid (0.19 ±â€¯0.02 mg/g), The second extract, extracted with ethanol as solvent, was a γ-oryzanol enriched fraction with a content of 14.41 ±â€¯0.26 mg/g extract. The optimized rice bran extracts thus obtained were subjected to a process of human in-vitro digestion. In the first extract, with high polyphenol content, the phenolic content was oscillating during the digestion, like antioxidant activity. The oryzanol content found in this fraction (0.079 ±â€¯0.002 mg/g) has not been detected in any phase of digestion. In the second extract, with a high oryzanol content at the beginning, oryzanol content was not detected in any of digestion steps. However, phenolic composition was stable in all phases of simulation (ranging from 0.117 and 0.094 mg/g in the case of ferulic acid). This fact evidence that oryzanol is not a bioavailability fraction, while phenolic compounds support to some extent, the conditions of digestion.

Synthesis and antiproliferative activity of peracetylated 2-amino-1,2-dideoxy-1-nitro-d-glycero-l-manno and d-glycero-d-talo heptitols.

Michael additions between carbohydrate derived nitroalkenes and several aliphatic and aromatic amines proceeded in a stereoselective way, leading to peracetylated 2-amino-1,2-dideoxy-1-nitro-heptitols. In addition, the antiproliferative activity of some of the new adducts has been studied. The results allowed to identify lead compounds which show GI50 values in the range 1.7-19µM.