Development of eco-friendly porous fired clay bricks using pore-forming agents: a review.

Today, clay bricks are facing technological challenges and are uncompetitive compared to materials such as concrete. Their performance must be improved if they are to stand up to the competition. Increasing environmental concerns over the accumulation of unmanaged wastes from agricultural or industrial productions have made these good candidates for incorporation into building materials to improve their performance. This process leads to the formation of pores in the bricks, producing lightweight and sustainable building materials. This paper reviews the different pore-forming agents from renewable or mineral resources as described in the literature. It also presents the impact of pore-forming agents on the physical, mechanical and thermal properties of clay bricks.

Extraction, Characterization, and Nutraceutical Potential of Prosthechea karwinskii Orchid for Insulin Resistance and Oxidative Stress in Wistar Rats.

Prosthechea karwinskii is an endemic orchid of Mexico with cultural significance for its ornamental, food, religious, and medicinal uses. In traditional medicine, diabetic patients use the leaves of this plant to lower glucose levels. The present study evaluated the effect of P. karwinskii leaves extract on the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in a model of obese rats with insulin resistance for its nutraceutical potential to reduce insulin resistance and oxidative stress. Obesity and insulin resistance were induced with 40% sucrose in water for 20 weeks. Four groups (control rats, obese rats, obese rats administered the extract, and obese rats administered metformin) were evaluated. Extract compounds were identified by UHPLC-ESI-qTOF-MS/MS. Glucose, insulin, triglyceride, and insulin resistance indices (HOMA-IR and TyG), as well as the activity of the antioxidant enzymes, increased in rats in the obese group. Administration of P. karwinskii extract and metformin reduced glucose, insulin, triglyceride, and insulin resistance indices and antioxidant enzyme activity to values similar to those of the control group. Therefore, this study shows the nutraceutical potential of P. karwinskii extract as an ingredient in the formulation of dietary supplements or functional foods to help treat diseases whose pathophysiology is related to oxidative stress and insulin resistance.

Effect of Microwave and Ultrasound during the Killing Stage of the Curing Process of Vanilla (Vanilla planifolia, Andrews) Pods.

The curing process (CP) of Vanilla planifolia pods, which is a long and tedious process, is necessary to obtain the natural vanilla extract. This research evaluated the application of microwave (M) and ultrasound (U) during the "killing" stage of the CP and its effect on vanillin content and ß-glucosidase activity. The pods were immersed in a container with water or with moistened samples for the M treatments. In U treatments, the pods were immersed in an ultrasonic bath. After this stage, the samples were subjected to an additional U treatment. The results show that the application of these technologies significantly improves vanillin yield (p < 0.05) and the curing time is reduced to 20 days. U treatments subjected to additional sonication at 38 °C obtain more than double the yield of vanillin regarding control. The effect of M and U on cell structure damage increases with additional sonication, but at 15 min, ß-glucosidase inactivation decreases the final yield. Disposition of samples in M also affects the final vanillin content. There is no significant correlation between ß-glucosidase and vanillin in the different treatments. The application of M and U with the appropriate parameters reduces the CP time without affecting the compounds of interest.

Validation of the traditional medicinal use of a Mexican endemic orchid (Prosthechea karwinskii) through UPLC-ESI-qTOF-MS/MS characterization of its bioactive compounds.

Ethnopharmacological relevance: The orchid Prosthechea karwinskii is a medicinal orchid in Oaxaca, Mexico, used to treat diabetes, cough, wounds, and burns, prevent miscarriage and assist in labor. Each part of the plant (leaves, pseudobulbs, or flowers) is used by healers for certain treatment conditions, indicating that each part has different biocompounds with specific pharmacological activity. Aim of the study: To characterize the biocompounds in extracts from leaves, pseudobulbs, and flowers of P. karwinskii and evaluate their ROS inhibition capacity to associate it with medicinal uses. Materials and methods: The compounds present in extracts from leaves, pseudobulbs, and flowers of P. karwinskii were identified by UPLC-ESI-qTOF-MS/MS. The chemical differentiation of each extract was tested by principal component analysis (PCA) using compound intensity values. For each extract, total phenol and flavonoid contents were quantified. Their antioxidant capacity was evaluated ex vivo by inhibition of ROS with DCFH-DA and in vitro with DPPH radical. Results: Based on the PCA, it was observed that some compounds were completely separated from others according to the correlation that they presented. The compounds common to all three plant parts were quinic, malic, succinic, azelaic, and pinellic acids. Among the compounds identified, two were exclusive to leaves, four to pseudobulbs, and ten to flowers. Some of the identified compounds have well-known antioxidant activity. The leaves had the highest content of total phenols and flavonoids, and the highest in vitro and ex vivo antioxidant capacity. A strong correlation was observed between phenol and flavonoid contents, and antioxidant capacity ex vivo and in vitro. Conclusions: It was found that the bioactive compounds and antioxidant capacity of each part of the plant were associated with its traditional medicinal use. A pharmacological potential was also found in P. karwinskii for further biological studies because of the type of compounds it contained.

Antimicrobial and antioxidant properties of methanol extract, fractions and compounds from the stem bark of Entada abyssinica Stend ex A. Satabie.

BACKGROUND: The aim of this study was to evaluate the antimicrobial and antioxidant activities of the methanol extract, fractions and isolated compounds from Entada abyssinica stem bark, plant used traditionally against gastrointestinal infections. METHODS: The methanol extract of E. abyssinica stem bark was pre-dissolved in a mixture of methanol and water, and then partitioned between n-hexane, ethyl acetate and n-butanol. The ethyl acetate portion was fractionated by column chromatography and the structures of isolated compounds elucidated by analysis of spectroscopic data and comparison with literature data. Antimicrobial activity was assayed by broth microdilution techniques on bacteria and yeasts. The antioxidant activity was determined by DPPH radical scavenging method. RESULTS: Four known compounds [(5S,6R,8aR)-5-(carboxymethyl)-3,4,4a,5,6,7,8,8a-octahydro-5,6,8a-trimethylnaphthalenecarboxylic acid (1), methyl 3,4,5-trihydroxybenzoate (2), benzene-1,2,3-triol (3) and 2,3-dihydroxypropyltriacontanoate (4)] were isolated. Compared to the methanol extract, fractionation increased the antibacterial activities of the n-hexane and ethyl acetate fractions, while the antifungal activities increased in ethyl acetate, n-butanol and aqueous residue fractions. The isolated compounds were generally more active on bacteria (9.7 to 156.2 µg/ml) than yeasts (78.1 to 312.5 µg/ml). Apart from compound 1, the three others displayed DPPH· scavenging activity (RSa), with RSa50 values of 1.45 and 1.60 µg/ml. CONCLUSION: The results obtained from this study support the ethnomedicinal use of E. abyssinica in the treatment of gastrointestinal infections and the isolated compounds could be useful in the standardisation of antimicrobial phytomedicine from this plant.

VOC and carbonyl compound emissions of a fiberboard resulting from a coriander biorefinery: comparison with two commercial wood-based building materials.

Indoor air quality is a major public health issue. It is related to the choice of construction materials and associated with VOC emissions. Two wood-based commercial panels were tested: a medium-density fiberboard (MDF) and a chipboard (CH), and they were compared to a material produced from a coriander biorefinery (COR). Indicators chosen to compare the materials were physical properties (density, bending properties, surface hardness, thickness swelling, and water absorption) and VOC emissions. Emissions were evaluated in an environmental chamber at 23 °C, 31 °C, and 36 °C, and during 28 days. Carbonyl emissions on day 1 at 23 °C were 74, 146, and 35 µg m-2 h-1, respectively, for MDF, CH, and COR. Terpenic emissions were 12, 185, and 37 µg m-2 h-1, respectively. Higher temperature resulted in higher emissions which decreased over time, except for formaldehyde. VOC emissions depended largely on material and temperature. Formaldehyde emission was 300 to 600 times lower for coriander boards (< 0.2 µg m-2 h-1), making them significantly more environmentally friendly materials in comparison with MDF and chipboard. These results highlight the interest of coriander by-products as raw materials for producing fiberboards with low impact on indoor air quality.

Pressurized water extraction of isoflavones by experimental design from soybean flour and Soybean Protein Isolate.

A Doehlert experimental design was conducted and surface response methodology was used to determine the effect of temperature, contact time and solid liquid ratio on isoflavone extraction from soybean flour or Soybean Protein Isolate in pressurized water system. The optimal conditions conducted gave an extraction yield of 85% from soybean flour. For Soybean Protein Isolate compared to soybean flour, the isoflavone extraction yield is 61%. This difference could be explained by higher aglycon content, while aglycon appears to be the least extracted isoflavone by pressurized water. The solid liquid ratio in the ASE cell was the overriding factor in obtaining high yields with both soybean products, while temperature has less influence. A high temperature causes conversion of the malonyls-glucosides and glucosides isoflavone derivatives into glucosides or aglycons forms. pressurized water extraction showed a high solubilization of protein material up to 95% of inserted Soybean Protein Isolate.

Suitability assessment of a continuous process combining thermo-mechano-chemical and bio-catalytic action in a single pilot-scale twin-screw extruder for six different biomass sources.

A process has been validated for the deconstruction of lignocellulose on a pilot scale installation using six types of biomass selected for their sustainability, accessibility, worldwide availability, and differences of chemical composition and physical structure. The process combines thermo-mechano-chemical and bio-catalytic action in a single twin-screw extruder. Three treatment phases were sequentially performed: an alkaline pretreatment, a neutralization step coupled with an extraction-separation phase and a bioextrusion treatment. Alkaline pretreatment destructured the wall polymers after just a few minutes and allowed the initial extraction of 18-54% of the hemicelluloses and 9-41% of the lignin. The bioextrusion step induced the start of enzymatic hydrolysis and increased the proportion of soluble organic matter. Extension of saccharification for 24h at high consistency (20%) and without the addition of new enzyme resulted in the production of 39-84% of the potential glucose.

Response surface methodology to optimise Accelerated Solvent Extraction of steviol glycosides from Stevia rebaudiana Bertoni leaves.

Following the approval of steviol glycosides as a food additive in Europe in December 2011, large-scale stevia cultivation will have to be developed within the EU. Thus there is a need to increase the efficiency of stevia evaluation through germplasm enhancement and agronomic improvement programs. To address the need for faster and reproducible sample throughput, conditions for automated extraction of dried stevia leaves using Accelerated Solvent Extraction were optimised. A response surface methodology was used to investigate the influence of three factors: extraction temperature, static time and cycle number on the stevioside and rebaudioside A extraction yields. The model showed that all the factors had an individual influence on the yield. Optimum extraction conditions were set at 100 °C, 4 min and 1 cycle, which yielded 91.8% ± 3.4% of total extractable steviol glycosides analysed. An additional optimisation was achieved by reducing the grind size of the leaves giving a final yield of 100.8% ± 3.3%.

Coupled extruder-headspace, a new method for analysis of the essential oil components of Coriandrum sativum fruits.

A new method involving concurrent single screw extruder combined with continuous headspace dynamic for the extraction and identification of the essential oil of Coriandrum sativum L. fruit was developed. The effect of six different nozzle diameters (5, 6, 7, 8, 9 and 10 mm) on the content and chemical composition of the essential oil of coriander fruit was studied. The oils from fruit samples were obtained by OMEGA 20 extruder. The result showed that the highest yield (0.53%) was obtained by the diameter of the nozzle was 8mm. Twenty-nine components were determined in essential oils, which were mostly hydrocarbons and alcohol monoterpenes. The main components linalool, α-pinene, γ-terpinene, p-cymene and limonene showed significant variations with drying trials.

Antifungal Properties of Chenopodium ambrosioides Essential Oil Against Candida Species.

The essential oil of the aerial part (leaves, flowers and stem) of Chenopodium ambrosioides was obtained by hydrodistillation and its chemical composition analyzed by GC and GC/MS, which permitted the identification of 14 components, representing 98.8% of the total oil. Major components were α-terpinene (51.3%), p-cymene (23.4%) and p-mentha-1,8-diène (15.3%). The antifungal properties of this essential oil were investigated in vitro by the well diffusion and broth microdilution methods. The in vitro antifungal activity was concentration dependent and minimum inhibitory concentration values varied from 0.25 to 2 mg/mL. The in vivo antifungal activity was evaluated on an induced vaginal candidiasis rat model. The in vivo activity of the oil on mice vaginal candidiasis was not dose-dependent. Indeed, all the three tested doses; 0.1%, 1% and 10% led to the recovery of mice from the induced infection after 12 days of treatment. The effect of the essential oil on C. albicans ATCC 1663 fatty acid profile was studied. This oil has a relatively important dose-dependent effect on the fatty acids profile.

Antidiarrheal activity of extracts and compound from Trilepisium madagascariense stem bark.

OBJECTIVE: The present study was performed to evaluate the preventive and curative antidiarrheal effects of the methanol extract, fractions and compound from the stem bark of Trilepisium madagascariense in rats. MATERIALS AND METHODS: The methanol extract from the stem bark of T. madagascariense, its fractions (n-hexane, ethyl acetate, n-butanol and aqueous residue) and compound (obtained from further column chromatography of the ethyl acetate fraction) were evaluated for the antidiarrheal activity in rats. These test samples (at 100, 200 and 400 mg/kg for the extract and fractions and 2.5 mg/kg for compound) were assayed on the latent periods, purging indices and fecal frequencies in castor oil-induced diarrhea. Gastrointestinal transit and castor oil-induced enteropooling assays were conducted. Shigella-induced diarrhea was assayed. Blood chemistry and fecal Shigella load were examined. RESULTS: The fractionation of the ethyl acetate fraction from the methanol extract of T. madagascariense afforded a known compound [isoliquiritigenin (1)]. Compound 1 increased the latent period of diarrhea induction (179.40 min) compared to the saline control (60.80 min). The purging indices, fecal frequencies and intestinal enteropooling decreased with an increase in the dose of test samples. The blood cell counts, sera creatinine and fecal Shigella load decreased significantly (P ≤ 0.05) in the plant extract-treated rats compared to the saline control. CONCLUSION: The results of our study, being reported for the first time, provide clear evidence that the methanol extract, fractions and isoliquiritigenin from T. madagascariense stem bark possess antidiarrheal activities.