Bioinformatics tools for the study of bioactive peptides from vegetal sources: evolution and future perspectives.

Bioactive peptides from vegetal sources have been shown to have functional properties as anti-inflammatory, antioxidant, antihypertensive or antidiabetic capacity. For this reason, they have been proposed as an interesting and promising alternative to improve human health. In recent years, the numerous advances in the bioinformatics field for in silico prediction have speeded up the discovery of bioactive peptides, also reducing the associated costs when using an integrated approach between the classical and bioinformatics discovery.

Brewers' spent hop revalorization for the production of high added-value cosmetics ingredients with elastase inhibition capacity.

This article summarizes the analysis of α and β-acids and prenylflavonoids from brewers' spent hop (BSH) as source of bioactive molecules to improve skin integrity by inhibiting elastase activity. To maximize the efficacy of the BSH extracts, it was necessary to identify the most bioactive hop compounds and the extraction parameters to maximize elastase inhibition and total antioxidant capacity. Thus, a computational methodology was carried out to test the anti-elastase potential of these hop molecules, detecting cis-iso-α-cohumulone and 8-prenylnaringenin as main inhibitors.

MIRATE: MIps RATional dEsign Science Gateway.

Molecularly imprinted polymers (MIPs) are high affinity robust synthetic receptors, which can be optimally synthesized and manufactured more economically than their biological equivalents (i.e. antibody).

Virtual Screening of Receptor Sites for Molecularly Imprinted Polymers.

Molecularly Imprinted Polymers (MIPs) are highly advantageous in the field of analytical chemistry. However, interference from secondary molecules can also impede capture of a target by a MIP receptor. This greatly complicates the design process and often requires extensive laboratory screening which is time consuming, costly, and creates substantial waste products.

Water-compatible imprinted pills for sensitive determination of cannabinoids in urine and oral fluid.

A novel molecularly imprinted solid phase extraction (MISPE) methodology followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) has been developed using cylindrical shaped molecularly imprinted pills for detection of Δ(9)-tetrahydrocannabinol (THC), 11-nor-Δ(9)-tetrahydrocannabinol carboxylic acid (THC-COOH), cannabinol (CBN) and cannabidiol (CBD) in urine and oral fluid (OF). The composition of the molecular imprinted polymer (MIP) was optimized based on the screening results of a non-imprinted polymer library (NIP-library). Thus, acrylamide as functional monomer and ethylene glycol dimethacrylate as cross-linker were selected for the preparation of the MIP, using catechin as a mimic template.

Volatile phenols depletion in red wine using molecular imprinted polymers.

Wines can be modified by microorganisms during the ageing process, by producing off-flavours like volatile phenols (VP), leading to their deterioration, with great economic losses. The development of methods to recover wines affected by unwanted VP became an important target. Molecular imprinted polymers (MIPs) are synthetic materials with artificially-generated recognition sites for selective extraction of organic compounds from different matrices.

Plasticized poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends incorporated with catechin intended for active food-packaging applications.

Active biobased packaging materials based on poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends were prepared by melt blending and fully characterized. Catechin incorporation, as antioxidant compound, enhanced the thermal stability, whereas its release was improved by the addition of acetyl(tributyl citrate) (ATBC) as plasticizer. Whereas the incorporation of ATBC resulted in a reduction of elastic modulus and hardness, catechin addition produced more rigid materials due to hydrogen-bonding interactions between catechin hydroxyl groups and carbonyl groups of PLA and PHB.

Analytical determination of flavonoids aimed to analysis of natural samples and active packaging applications.

Several HPLC and UHPLC developed methods were compared to analyse the natural antioxidants catechins and quercetin used in active packaging and functional foods. Photodiode array detector coupled with a fluorescence detector and compared with LTQ-Orbitrap-MS was used. UHPLC was investigated as quick alternative without compromising the separation, analysis time shortened up to 6-fold.

Enhancing the release of the antioxidant tocopherol from polypropylene films by incorporating the natural plasticizers lecithin, olive oil, or sunflower oil.

In this work, natural plasticizers-modified polypropylenes intended for food active packaging were developed. Sunflower oil, olive oil, and soy lecithin, without any known harmful effects or toxicity, were employed as natural plasticizers, also implementing the attractiveness of using synthetic plastics on active packaging developments. Their incorporation during the extrusion of polypropylene was tried as a means to obtain polymers with improved diffusion paths, allowing differences in antioxidant release rates for active packaging materials.

Improving the capacity of polypropylene to be used in antioxidant active films: incorporation of plasticizer and natural antioxidants.

Two types of active antioxidant food packages with improved release properties, based on polypropylene (PP) as one of the most common polymers used in food-packaging applications, were developed. Incorporation of catechin and green tea as antioxidant provided PP with 6 times higher stabilization against thermal oxidation. Release of natural antioxidants (catechins, gallic acid, caffeine, and quercetin) into various food simulants from that nonpolar matrix were improved by blending poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) (PPG-PEG-PPG) as plasticizer into the polymer formulation.

Interaction and release of catechin from anhydride maleic-grafted polypropylene films.

In this paper, investigations were carried out on catechin-loaded maleic anhydride (MAH)-modified polypropylenes (PP). Two maleic-modified polypropylenes (PPMAH) with different maleic concentrations have been blended with PP and catechin to obtain composites of improved catechin retention with the aim of studying the possible interactions between these grafted polymers with antioxidants, and a secondary interest in developing an active antioxidant packaging. Composite physicochemical properties were measured by thermal analysis (thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and oxidation induction time (OIT)) and infrared spectroscopy studies.

Effect of PPG-PEG-PPG on the tocopherol-controlled release from films intended for food-packaging applications.

The feasibility of novel controlled release systems for the delivery of active substances from films intended for food packaging was investigated. Because polyolefins are used highly for food-packaging applications, the reported high retention degree of antioxidants has limited their use for active packaging. Thus, in this study, PP films modified with different chain extenders have been developed to favor and control the release rates of the low molecular weight antioxidant tocopherol.

Application of liquid chromatography in polymer non-ionic antistatic additives analysis.

This article investigates the applicability of HPLC-UV, ultra performance LC-evaporative light-scattering detection (UPLC-ELSD), HPLC-ESI(+)-MS and HPLC-hybrid linear ion trap (LTQ) Orbitrap MS for the analysis of different non-ionic antistatic additives, Span 20, Span 60, Span 65, Span 80, Span 85 (sorbitan fatty acid esters), Atmer 129 (glycerol fatty acid ester) and Atmer 163 (ethoxylated alkylamine). Several alkyl chain length or different degrees of esterification of polyol derivatives can be present in commercial mixtures of these polymer additives. Therefore, their identification and quantification is complicated.

Liquid chromatographic methods to analyze hindered amines light stabilizers (HALS) levels to improve safety in polyolefins.

A chromatographic method using ultra performance LC with ultraviolet spectrophotometry detection system (UPLC-UV-visible (UV/Vis)) (UPLC, ultra performance LC) was developed to determine Chimassorb 944 and Tinuvin 770, high- and low-molecular mass hindered amine light stabilizers, respectively. The use of a bridge ethylene hybrid-based particles C(18) UPLC column, being compatible with a buffered mobile phase adjusted to pH 11.5, was used to achieve a satisfactory elution of possible non-ionizated units of polymeric Chimassorb 944.

Development of an ultraperformance liquid chromatography method for improved determination of additives in polymeric materials.

An analytical method for the simultaneous separation and quantitation of ten colorants and six antioxidants used as polymer additives has been developed by transferring chromatographic conditions from two independent HPLC methods to a single ultraperformance liquid chromatography system. An experimental design was carried out to achieve the best elution gradient for separation of all the studied compounds with the best possible peak resolution and in the shortest possible analysis time. The new method gives good values for the analytical quality parameters evaluated.

As, Hg, and Se flue gas sampling in a coal-fired power plant and their fate during coal combustion.

As, Hg, and Se are the most volatile elements in the flue gas from a coal-fired power plant. Significant amounts of these elements cause an undesired direct gaseous emission, which leads to a serious environmental health risk. The main focus of this study is to evaluate the possibility of simultaneous sampling of these volatile elements using an accurate official method for Hg (the most volatile element).