Structure–antioxidant activity relationships of flavonoids isolated from different plant species

In the course of our phytochemical studies of different plants from developing countries we isolated and structurally characterized several flavonoid derivatives (compounds 1–26), both aglycones and glycosides, typical of the species investigated. The aim of this study was to evaluate varieties of medicinal plants that were growing in developing countries, known in traditional medicine as anti-inflammatory remedies, with respect to their flavonoidic isolated constituents, assuming that their anti-inflammatory activity could be explained, at least in part, by the presence of antioxidant principles. The antioxidant activities of compounds 1–26 were evaluated by measuring their ability to scavenge the radical cation 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate) (ABTS⁺) and the superoxide anion, to inhibit β-carotene oxidation in a lipid micelle system, and to inhibit xanthine oxidase activity, showing some structure–activity relationships.     

Structure–function relationship of fermented skate skin gelatin-derived bioactive peptides: a peptidomics approach

Food Science and Biotechnology - In this study, we investigated the multi-functionality of bioactive peptides derived from fermented skate (Raja kenojei) skin gelatin hydrolysates. The extracted...     

Physico–chemical,thermal and pasting properties of fractions obtained during three successive reduction milling of different corn types

The physico–chemical, thermal and pasting properties of fractions obtained during three successive reduction milling of degermed grains of four corn types (popcorn, sweet corn, dent corn, and white corn) was studied. Popcorn and white corn gave higher coarser fraction (14–20 mesh) yield than dent and sweet corn. Protein content progressively decreased with increase in fineness in the particle size. Fractions of first reduction stage showed higher fat content and L^∗ value; and lower b^∗ value than the fractions from second and third reduction stages. L^∗ value increased whereas ‘a^∗’ and ‘b^∗’ values decreased with increase in fineness of the fractions. T_o, T_p and ΔH_gel, peak viscosity, breakdown, setback and final viscosity increased while pasting temperature decreased with increase in fineness of the fractions. The results showed that the successive reduction dry milling of a single corn type could produce fractions with varied characteristics.     

Structure–activity relationship and molecular docking analysis of cysteine-containing dipeptides as antioxidant and ACE inhibitory

Comparative molecular field analysis (CoMFA), comparative similarity index analysis (CoMSIA) and hologram QSAR (HQSAR) were used to identify the relationship between the structure of cysteine-containing dipeptide with antioxidant and ACE inhibitory activity; then, molecular docking, ADME prediction and thermostability assay were applied to illustrate the performance in docking with ACE, metabolic information and thermostability of the strongest activity dipeptide. According to pIC₅₀ of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azinobis-(3-ethyl-benzothiazoline-6-sulphonate) (ABTS), constructed CoMFA, CoMSIA and HQSAR models predicted the structural properties of carboxyl of C-terminus impacted on the antioxidant activity. The properties of side chain of C-terminus influenced on the ACE inhibitory activity based on CoMFA, CoMSIA and HQSAR models. As the strongest multifunctional cysteine-containing dipeptide, CW interacted with ACE by S1 pocket, S2 pocket, Zn²⁺. It was promising for CW to utilise in the functional foods due to less interference in normal life activities, high oral bioavailability and stability under 70 °C.     

Thermal and mass transport properties of polyester–cotton plated fabrics in relation to back layer fibre profiles and face layer yarn types

Clothing plays an important role in maintaining thermal equilibrium between a human body and the ambient environment by serving as a medium for heat, moisture vapour and liquid moisture transfer. The ability of fabric to maintain this equilibrium is related to thermo-physiological comfort. Plating is an innovative knitted fabric production technique to obtain bi-layered fabrics. An attempt has been made to engineer plated knit structures with such a combination of fibre cross section in the back (inner/next to skin) and the yarn type in the face (outer) layer, so that a rapid liquid transfer from back layer by wicking and quick liquid absorption and evaporation by the face layer can be achieved. Plated fabrics using the combination of triangular polyester fibre in the back and carded cotton yarn in the face layer showed the higher thermal resistance, higher absorbent capacity and would be warmer to the initial touch. However, the combination of combed cotton yarn with triangular polyester fibre resulted in fabrics with the higher air permeability, moisture vapour transmission rate and transplanar wicking.     

Studies on cotton–acrylic bulked yarns produced from different spinning technologies. Part I: yarn characteristics

The effects of different factors, namely spinning technologies (ring, rotor and DREF-II, i.e. Group A yarns), position of shrinkable acrylic feed sliver in DREF-II friction spinning system (Group B yarns) and proportion of shrinkable acrylic core fibre in core-sheath type DREF-III friction spun yarns (Group C yarns) on various properties of cotton-acrylic–blended bulked yarns have been studied. The bulk in the yarns was developed by relaxing shrinkable acrylic component of the yarns using boiling water treatment. All the above factors have a significant impact on various properties of cotton–acrylic blended bulked yarns. For all the yarns, after boiling treatment, there is lengthwise shrinkage of yarns and the specific volume also increases. Tenacity and breaking elongation of all the yarns of Group A and Group B increase after hot water treatment, whereas in case of core-sheath type DREF-III yarns (Group C yarns) there is drop in tenacity and breaking elongation after similar treatment. In general, for all the yarns the flexural rigidity of the yarns reduces and compressibility and compressional recovery of increases after bulking treatment.     

Modelling of thermal conductivity of knitted fabrics made of cotton–bamboo yarns using artificial neural network

Regenerated cellulosic fibre made from bamboo is gaining popularity for apparel use due to its improved functional properties. This paper presents the modelling of thermal conductivity of knitted fabrics made from blended yarns of cotton and bamboo fibres using an artificial neural network (ANN). Five parameters, namely knitted fabric structure type, yarn linear density, bamboo fibre proportion (%), fabric thickness and fabric areal density, were used as inputs to the ANN model. The developed model was able to predict the thermal conductivity of fabrics with very good accuracy. The trend analysis of the developed model revealed the influence of various input parameters on the thermal conductivity of knitted fabrics. These findings can be judiciously used for the selection of optimum material and structural parameters of knitted cellulosic fabrics for a particular end‐use.     

Edible films made from blends of manioc starch and gelatin – Influence of different types of plasticizer and different levels of macromolecules on their properties

The interest in the development of edible and biodegradable films has increased because it is every day more evident that non-degradable materials are doing much damage to the environment. In this research, bioplastics were based on blends of manioc starch (native and modified) and gelatin in different proportions, added of glycerol or sorbitol, which were used as plasticizers. The objective was to study the effect of two different plasticizers, glycerol and sorbitol, and different concentrations of starch and gelatin on the barrier (water vapor permeability – WVP), mechanical (tensile strength and elongation at break), physicochemical (solubility in water and in acid) and physical properties (opacity and thickness) of the obtained bioplastics samples. As a result, all of them showed transparency and resistance to tensile strength, as well as increasing in thickness values and in the WVP, as the gelatin content increased in the formulations. Finally, all results for tensile strength and elongation at break obtained for those samples plasticized with sorbitol were better than those plasticized with glycerol.     

Process–Structure–Function Relations of Pectin in Food

Pectin, a complex polysaccharide rich in galacturonic acid, has been identified as a critical structural component of plant cell walls. The functionality of this intricate macromolecule in fruit- and vegetable-based–derived products and ingredients is strongly determined by the nanostructure of its most abundant polymer, homogalacturonan. During food processing, pectic homogalacturonan is susceptible to various enzymatic as well as nonenzymatic conversion reactions modifying its structural and, hence, its functional properties. Consequently, a profound understanding of the various process–structure–function relations of pectin aids food scientists to tailor the functional properties of plant-based derived products and ingredients. This review describes the current knowledge on process–structure–function relations of pectin in foods with special focus on pectin's functionality with regard to textural attributes of solid plant-based foods and rheological properties of particulated fruit- and vegetable-derived products. In this context, both pectin research performed via traditional, ex situ physicochemical analyses of fractionated walls and isolated polymers and pectin investigation through in situ pectin localization are considered.     

Structure–mechanism relationship of antioxidant and ACE I inhibitory peptides from wheat gluten hydrolysate fractionated by pH

The aims of this study were to assess bioactive properties (ACE inhibition and antioxidant capacity) from wheat gluten hydrolysate peptides fractionated by pH (4.0, 6.0 and 9.0), to determine peptide action mechanism, and to relate it to the secondary structure and functional groups of peptides. Gluten hydrolysate extracts (GHE) were enriched in peptides with medium hydrophobicity and molecular weight (≈ 60% MH and 5.5 kDa, respectively). Gluten peptides inhibited ACE I by uncompetitive mechanism and a direct relationship between α-helix structure and IC50% value was obtained (r = 0.9127). TEAC and cooper chelating activity from GHE 6.5 were the highest and directly correlated with MH peptides. GHE 9.0 had high carotene bleaching inhibition (47.5 ± 0.3%) and reducing power activity (163.1 ± 2.9 mg S₂O₃^2 − equivalent g^− 1 protein), which were directly related to disulfide bonds content of peptides (r = 0.9982 and 0.9216, respectively). pH was a good alternative to select bioactive peptides from wheat gluten hydrolysate.     

Tensile behavior of staple fiber yarns,part IV: experimental verification of predicted stress–strain curves

In this paper, specific stress–strain curves were predicted for viscose, cotton, and polyester yarns spun by ring and rotor technologies. The average fiber-specific stress–strain curves were used to predict yarn-specific stress–strain curves. The predicted yarn-specific stress–strain curves captured the experimental yarn-specific stress–strain curves well both in shape and position for the three studied yarn types. However, higher prediction error was observed relatively in polyester yarns due to more slippage of fibers in these yarns. All rotor yarns exhibited higher difference between experimental and predicted results which might be the result of the nature of the twist in rotor yarn.     

Tribological properties of aramid–polypropylene composites from commingled yarns: influence of aramid fibre weight fraction

Commingling process involves the mixing of two types of filaments, viz. reinforcing and matrix-forming filaments in a nozzle with the help of compressed air leading to a homogenous distribution. During compression moulding, close placement of reinforcing and matrix-forming filaments reduces the mass transfer distance of the matrix and ensures proper wetting of fibres resulting in the enhanced properties of the composites. Three types of compression-moulded composites of polypropylene and Kevlar with different Kevlar fibre weight fractions were developed using commingled yarns. Studies on mechanical properties of these laminates confirmed that the composites having higher weight fraction of Kevlar fibre showed better tensile properties. Both abrasive and erosive wear rates showed a strong influence of Kevlar fibre weight fraction. With increase in weight fraction of Kevlar fibre, the erosion wear rate of the composites decreased as Kevlar fibres have higher wear resistance compared with polypropylene matrix. Similar trend was observed also in case of abrasive wear. The composites showed higher wear resistance while abrading the composite with polymer pin in a direction perpendicular to the fibre orientation as compared with abrading in a direction parallel to the fibre orientation.     

The influence of temperature on residual deformation of Phenylon and Nomex yarns following the creep–recovery process

High-performance synthetic filaments and yarns are subjected to different loads and temperature during their practical and industrial applications, resulting in changes in their mechanical properties. Knowledge of the deformation and strength properties of these polymer materials at various temperatures and different levels of preliminary stretching is therefore very important. Semi-rigid chain polymers Phenylon and Nomex yarns are popular materials for use at high temperatures. Their mechanical properties can be changed significantly at high temperatures. It is also shown that preliminary stretching of Phenylon and Nomex yarns at more than 5% will change the nature of the stress–strain curves due to the rearrangement of the supermolecular structures which occur at this elongation. However, there is no change in the character of accumulation of residual deformation at elevated temperatures for Phenylon and Nomex yarns.     

The impact of nitrogen low temperature plasma treatment upon the physical–chemical properties of polyester fabric

An approximate theoretical analysis of the cantilever stiffness test is presented. This yields convenient formulae for calculating the bending parameters of fabrics. The formulae show good agreement with Peirce's empirical equation and reasonable agreement with Grosberg and Swani's graphical method.