Screening of Novel Bioactive Peptides from Goat Casein: In Silico to In Vitro Validation

Food-derived bioactive peptides are of great interest to science and industry due to evolving drivers of food product innovation, including health and wellness. This study aims to draw attention through a critical study on how bioinformatics analysis is employed in the identification of bioactive peptides in the laboratory. An in silico analysis (PeptideRanker, BIOPEP, AHTpin, and mAHTPred) of a list of peptides from goat casein hydrolysate was performed to predict which sequences could potentially be bioactive. To validate the predictions, the in vitro antihypertensive potential of the five peptides with the highest potential was first measured. Then, for three of these, gastrointestinal digestion was simulated in vitro, followed by the analysis of the resulting ACE inhibitory activity as well as antioxidant capacity. We thus observed that the use of new computational biology technologies to predict peptide sequences is an important research tool, but they should not be used alone and complementarity with various in vitro and in vivo assays is essential.     

Use of focused open vessel microwave-assisted extraction as prelude for the determination of the fatty acid profile of fish – a comparison with results obtained after liquid-liquid extraction according to Bligh and Dyer

 A method based on microwave-assisted extraction (MAE) was developed to extract lipids from fish for the determination of the fatty acid composition. Microwave-assisted extraction was performed with an open-vessel extraction apparatus similar to the system of Soxhlet. The solvent was an equivolume mixture of ethyl acetate and cyclohexane. The solvent forms a ternary azeotrope with water, and water is separated after re-condensation in a water trap. With this technique, extraction can be performed without pre-drying of fish tissues. After lipid extraction, the esterification was performed with trimethylsulfonium hydroxide (TMSH) and the fatty acid methyl esters (FAMEs) were determined by GC/FID. The results were compared with those obtained after liquid-liquid extraction according to Bligh and Dyer. Fillets of mackerel (Scomber scombrus) and livers of cod (Gadus morhua) were used as the sample material. The water content (n=7) of the cod livers was 36.2±1.6% and that of mackerel fillets was 74.5±0.5%. The lipid contents (n=5) using the MAE method were 5.6±0.4% and 62.6±3.1% in mackerel and cod liver, respectively. Relative levels of 58 fatty acids (two co-eluted) were determined with GC/FID on two capillary columns with different polarity. These were 10 saturated, 24 unsaturated, and 24 unidentified peaks which are most likely unsaturated or branched-chain fatty acids. After MAE the composition of the 57 peaks was virtually the same as that obtained with the Bligh and Dyer method. The advantages are, however, that MAE is faster, requires less solvent, and avoids the use of chlorinated solvents and so is more environmentally friendly. Our results confirm that MAE is a well-suited alternative to the Bligh and Dyer method for the extraction of lipids followed by determination of the fatty acid profile. Received: 1 March 2000 / Revised version: 23 May 2000     

Molecular Markers for Assessing Must Varietal Origin

Wine quality and market value greatly depend on the grapevine varietal composition, which may be characteristic of specific regions. In order to defend the distinct regions, Denominations of Origin were defined to protect against fraudulent practices. In this study, we evaluated the efficiency of two microsatellite-based systems (microsatellite (SSR) and intermicrosatellite (ISSR)) for must varietal composition determination and their potential role in certification purposes. Eleven Vitis vinifera L. varieties from leaf and monovarietal must DNA samples were screened with six SSR and 14 ISSR primers to discriminate polymorphisms. Principal coordinates analysis was performed with DCENTER on the resultant data using unweighted pair group mathematical average and revealed that ISSRs markers were not suitable for certification procedures, whereas nuclear SSR markers presented a complete correspondence between leaf and must samples, demonstrating that they were adequate for traceability purposes.     

Kinetics of the xylitol crystallization in hydro-alcoholic solution

Nývlt method was used to determine the kinetic parameters of commercial xylitol in ethanol:water (50:50 %w/w) solution by batch cooling crystallization. The kinetic exponents (n, g and m) and the system kinetic constant (B_N) were determined. Model experiments were carried out in order to verify the combined effects of saturation temperatures (40, 50 and 60 °C) and cooling rates (0.10, 0.25 and 0.50 °C/min) on these parameters. The fitting between experimental and calculated crystal sizes has 11.30% mean deviation.     

Copper slag waste as a supplementary cementing material to concrete

Summary The use of industrial solid waste to concrete production is environmentally friendly because it contributes to reducing the consumption of natural resources, the pollution concrete production generates and the power it consumes. This paper presents the results of a study on the use of copper slag as pozzolanic supplementary cementing material for use in concrete. Initially, the chemical and mineralogical characteristics of the copper slag were determined. After this, concrete batches were made with copper slag additions of 20% (relative to the cement weight) and a set properties were investigated, i.e., specific gravity, compressive strength, splitting-tensile, absorption, absorption rate by capillary suction and carbonation. The results pointed out that there is a potential for the use of copper slag as a supplementary cementing material to concrete production. The concrete batches with copper slag addition presented greater mechanical and durability performance.     

Use of Ti in hard metal alloys – Part II: mechanical properties

WC‐Co hard metal is a material of high hardness, high compressive strength and wear resistance while maintaining good toughness and thermal stability. Samples of nanosized WC powders with 10 wt% Co, WC‐10 wt% Ti, WC‐9 wt% Ti‐1 wt% Co were cold pressed at 200 MPa and sintered at 1500°C during 1 hour under vacuum of 10^–2 mbar. The characterization of the sintered materials was performed by the measurements of densification, HV30 hardness, fracture toughness and compression strength. The results showed that it is possible to process a hard metal through a Powder Metallurgical conventional route from nanoscaled WC grains, using Ti (or a Ti‐Co mixture) as a binder phase, with good mechanical properties.     

A multicriteria model,based on the PROMETHEE II,for assessing corporate sustainability

Clean Technologies and Environmental Policy - As global inequality and climate change concerns increase, consumers and investors are looking for products and services that have been produced...     

Synthesis of Fatty Acetoacetates Under Microwave Irradiation Catalysed by Sulfamic Acid in a Solvent-Free System

The 1,3‐dicarbonyl compounds are important building blocks to obtain products with various biological activities and technological applications. In this work, we used a simple transesterification method to develop fatty acetoacetates in a solvent‐free medium using a green catalyst, sulfamic acid (NH₂SO₃H), under microwave irradiation. The experimental results demonstrate good yields in a short reaction time (13 min), which makes this method an efficient approach to synthesize fatty acetoacetates from a wide range of saturated, unsaturated, and polyunsaturated long chain fatty alcohols, and ricinoleic derivatives. Experiments of recycling of the catalyst were performed and no decrease in catalytic activity of sulfamic acid was observed.     

Effects of Root Isoquinoline Alkaloids from <Emphasis Type="Italic">Hydrastis canadensis</Emphasis> on <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> Isolated from <Emphasis Type="Italic">Hydrastis</Emphasis> Root Tissue

Goldenseal (Hydrastis canadensis L.) is a popular medicinal plant distributed widely in North America. The rhizome, rootlets, and root hairs produce medicinally active alkaloids. Berberine, one of the Hydrastis alkaloids, has shown antifungal activity. The influence of a combination of the major Hydrastis alkaloids on the plant rhizosphere fungal ecology has not been investigated. A bioassay was developed to study the effect of goldenseal isoquinoline alkaloids on three Fusarium isolates, including the two species isolated from Hydrastis rhizosphere. The findings suggest that the Hydrastis root extract influences macroconidia germination, but that only the combined alkaloids—berberine, canadine, and hydrastine—appear to synergistically stimulate production of the mycotoxin zearalenone in the Fusarium oxysporum isolate. The Hydrastis root rhizosphere effect provided a selective advantage to the Fusarium isolates closely associated with the root tissue in comparison with the Fusarium isolate that had never been exposed to Hydrastis.