Oxidative Stability of α‐Linolenic Acid in Corn Chips Enriched with Linseed Oil Pro/Antioxidative Activity of Tocopherol

Extruded products, particularly those which are corn‐based, are widely consumed salty or sweet snacks; moreover, they very often provide a basis for breakfast for people around the world. Extruded products are characterised by a low nutritional value, and a particularly low content of polyunsaturated fatty acids of the n‐3 group. An attempt was made to enrich extruded corn crisps with α‐linolenic acid (ALA) through the addition of refined linseed oil at an amount of 5 %. Corn crisps were produced with the addition of the oil concerned so that the concentration of ALA in the finished product was at least 2 g 100 g^?1 (in a portion). With such a content of ALA, the crisps may be classified as ‘functional food’ in accordance with Commission Regulation (EU) No 432/2012 of May 2012. The following were tested: oxidative stability, and changes to the content of ALA during 6‐month storage of crisps with the addition of linseed oil and various concentrations of δ‐tocopherol and ascorbic acid. The crisps were packed in polyamide/polyethylene barrier film packages (30/70 µm), using either atmospheric air of argon for the packaging process. The study showed that with each applied concentration of δ‐tocopherol added to the linseed oil (200–800 mg 100 g^?1), it had a strong pro‐oxidant effect. Packaging in argon atmosphere play very protective role in ALA stabilisation in functional corn crisp.     

Thermo‐Physical and Impact Properties of Epoxy Containing Epoxidized Linseed Oil, 2

Summary: Biobased neat epoxy materials containing epoxidized linseed oil (ELO) were processed with an amine curing agent. A defined amount of diglycidyl ether of bisphenol F (DGEBF) was replaced by ELO. The thermophysical properties of the amine‐cured biobased neat epoxy were measured by dynamic mechanical analysis (DMA). The Izod impact strength increased with an increase in the amount of ELO added. The change in the Izod impact strength was correlated with the thermophysical properties measured by DMA.

Relation between the Izod impact strength and loss factor for amine‐ and anhydride‐cured ELO‐containing epoxy resins.     

Thermo‐Physical and Impact Properties of Epoxy Containing Epoxidized Linseed Oil, 1

Summary: Biobased neat epoxy materials containing epoxidized linseed oil (ELO) were processed with an anhydride curing agent. A defined amount of the diglycidyl ether of bisphenol F (DGEBF) was replaced by ELO. The selection of the DGEBF, ELO, and an anhydride curing agent resulted in an excellent combination, to provide a new biobased epoxy material showing high elastic modulus, high glass transition temperature, and high heat distortion temperature (HDT) with larger amounts of ELO. The Izod impact strength was almost constant while changing the amount of ELO. This is a promising result for future industrial applications in different engineering industries.

The effect of changing ELO concentration of the anhydride‐cured neat epoxy on the storage modulus.     

Forms of n‐3 (ALA,C18:3n‐3 or DHA,C22:6n‐3) Fatty Acids Affect Carcass Yield,Blood Lipids,Muscle n‐3 Fatty Acids and Liver Gene Expression in Lambs

The effects of supplementing diets with n‐3 alpha‐linolenic acid (ALA) and docosahexaenoic acid (DHA) on plasma metabolites, carcass yield, muscle n‐3 fatty acids and liver messenger RNA (mRNA) in lambs were investigated. Lambs (n = 120) were stratified to 12 groups based on body weight (35 ± 3.1 kg), and within groups randomly allocated to four dietary treatments: basal diet (BAS), BAS with 10.7 % flaxseed supplement (Flax), BAS with 1.8 % algae supplement (DHA), BAS with Flax and DHA (FlaxDHA). Lambs were fed for 56 days. Blood samples were collected on day 0 and day 56, and plasma analysed for insulin and lipids. Lambs were slaughtered, and carcass traits measured. At 30 min and 24 h, liver and muscle samples, respectively, were collected for determination of mRNA (FADS1, FADS2, CPT1A, ACOX1) and fatty acid composition. Lambs fed Flax had higher plasma triacylglycerol, body weight, body fat and carcass yield compared with the BAS group (P < 0.001). DHA supplementation increased carcass yield and muscle DHA while lowering plasma insulin compared with the BAS diet (P < 0.01). Flax treatment increased (P < 0.001) muscle ALA concentration, while DHA treatment increased (P < 0.001) muscle DHA concentration. Liver mRNA FADS2 was higher and CPT1A lower in the DHA group (P < 0.05). The FlaxDHA diet had additive effects, including higher FADS1 and ACOX1 mRNA than for the Flax or DHA diet. In summary, supplementation with ALA or DHA modulated plasma metabolites, muscle DHA, body fat and liver gene expression differently.     

Dietary High‐Oleic Acid Soybean Oil Dose Dependently Attenuates Egg Yolk Content of n‐3 Polyunsaturated Fatty Acids in Laying Hens Fed Supplemental Flaxseed Oil

Chickens can hepatically synthesize eicosapentaenoic acid (20:5 n‐3) and docosahexaenoic acid (22:6 n‐3) from α‐linolenic acid (ALA; 18:3 n‐3); however, the process is inefficient and competitively inhibited by dietary linoleic acid (LNA; 18:2 n‐6). In the present study, the influence of dietary high‐oleic acid (OLA; 18:1 n‐9) soybean oil (HOSO) on egg and tissue deposition of ALA and n‐3 polyunsaturated fatty acids (PUFA) synthesized from dietary ALA was investigated in laying hens fed a reduced‐LNA base diet supplemented with high‐ALA flaxseed oil (FLAX). We hypothesized that reducing the dietary level of LNA would promote greater hepatic conversion of ALA to very long‐chain (VLC; >20C) n‐3 PUFA, while supplemental dietary HOSO would simultaneously further enrich eggs with OLA without influencing egg n‐3 PUFA contents. Nine 51‐week‐old hens each were fed 0, 10, 20, or 40 g HOSO/kg diet for 12 weeks. Within each group, supplemental dietary FLAX was increased every 3 weeks from 0 to 10 to 20 to 40 g/kg diet. Compared to controls, dietary FLAX maximally enriched the total n‐3 and VLC n‐3 PUFA contents in egg yolk by 9.4‐fold and 2.2‐fold, respectively, while feeding hens 40 g HOSO/kg diet maximally attenuated the yolk deposition of ALA, VLC n‐3 PUFA, and total n‐3 PUFA by 37, 15, and 32%, respectively. These results suggest that dietary OLA is not neutral with regard to the overall process by which dietary ALA is absorbed, metabolized, and deposited into egg yolk, either intact or in the form of longer‐chain/more unsaturated n‐3 PUFA derivatives.     

Simultaneous IR‐Spectroscopic Observation of α‐Synuclein,Lipids, and Solvent Reveals an Alternative Membrane‐Induced Oligomerization Pathway

The intrinsically disordered protein α‐synuclein (αS), a known pathogenic factor for Parkinson's disease, can adopt defined secondary structures when interacting with membranes or during fibrillation. The αS–lipid interaction and the implications of this process for aggregation and damage to membranes are still poorly understood. Therefore, we established a label‐free infrared (IR) spectroscopic approach to allow simultaneous monitoring of αS conformation and membrane integrity. IR showed its unique sensitivity for identifying distinct β‐structured aggregates. A comparative study of wild‐type αS and the naturally occurring splicing variant αS Δexon3 yielded new insights into the membrane's capability for altering aggregation pathways.     

Effect of Draw Ratio on Physical,Release, and Antibacterial Properties of Poly(ε‐caprolactone) Loaded with Lysozyme

In this work, some films of poly(ε‐caprolactone) (PCL) containing lysozyme at 5% by weight are obtained. Lysozyme is a natural antimicrobial molecule. The films are submitted to cold drawing process at three different draw ratios, λ = 3, 4, and 5, where λ is the ratio between final and initial length. Morphology, physical and barrier properties of the drawn samples are studied and correlated to the release of lysozyme. Tests against Bacillus sp are performed and correlated to the material texture. The molecular orientation of uniaxially drawn lysozyme doped PCL films is demonstrated to be a significant parameter for controlled release monitoring of the active molecule and the antimicrobial activity.     

Lower Concentration of n‐3 in the Red Blood Cells and Plasma of Lambs when their Dams were Fed a Diet High Compared with Low in n‐6 Fatty Acids at Joining

Feeding ewes a diet high in n‐6 in late gestation can affect fatty acid concentrations in the newborn lamb. The effect of feeding ewes a high n‐6 diet prior to conception and in early gestation on lamb n‐6 and n‐3 status has not previously been examined. The aim of the current study was to determine whether the concentration of n‐6 was higher and n‐3 was lower in lamb red blood cells (RBC) and plasma when Merino dams were fed a diet high in n‐6 either pre‐conception only or both pre‐conception and in early gestation. Dams were fed a diet low (silage) or high (oats/CSM) in n‐6 for either 6 weeks pre‐mating only or 6 weeks pre‐mating and 17 days post‐mating. The fatty acid status of lamb RBC and plasma was determined following birth and compared with dam fatty acids around parturition. The concentration of lamb RBC and plasma n‐3 was lower (p < 0.05) when dams received the high n‐6 compared with low‐n‐6 diet around mating, independent of the length of time of feeding. The concentration of n‐3 in lamb plasma was also higher when lambs were assessed as being likely rather than unlikely to have suckled prior to blood collection. Lamb RBC and plasma n‐3 fatty acids were lower when dams were fed the high compared with the low n‐6 diet for only a short time around mating. Transfer of fatty acids via the placenta and milk may account for the differences.     

Synthesis and characterization of new hydrogels on the basis of water‐soluble maleic anhydride copolymers with γ‐aminopropyltriethoxysilane

This work describes the synthesis and macromolecular reactions of maleic anhydride (MA)–acrylic acid (AA) binary reactive copolymers with γ‐aminopropyltriethoxysilane (APTS) as a polyfunctional crosslinker. Copolymers with a given composition of MA–AA (47.17–52.83 wt %) were synthesized by radical binary copolymerization with benzoyl peroxide as an initiator in p‐dioxane at 70°C in nitrogen atmosphere and initial monomer ratio of 1 : 1. It is shown that the network structure is formed in MA–AA/APTS in water by intermolecular reaction between the anhydride unit and the amine group, as well as between the etoxysilyl fragment and free carboxyl groups of the acrylic acid and maleic anhydride unit. Swelling parameters such as beginning time of hydrogel formation, initial rate of swelling, swelling rate constant, equilibrium swelling, and equilibrium water content were determined for copolymer/APTS/water systems with various copolymer/crosslinker ratios. Formation of a hyperbranched network structure through the fragmentation of side‐chain reactive groups in the studied systems was confirmed by FTIR, TGA, and DSC methods. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4009–4015, 2003     

Effect of Maleic‐Anhydride Grafting on the Physical and Mechanical Properties of Poly(L‐lactic acid)/Starch Blends

MA is grafted onto both PLLA and starch in an internal mixer in the presence of DCP in a one‐step reactive compatibilization process. The effect of maleation of MA on the physical and mechanical properties and morphology of the blends was assessed. The onset decomposition temperature of the PLLA/starch blends decreased as the starch content increases due to the lower thermal stability of starch and the low effect of the maleation reaction on the thermal stability of the blends. PLLA/starch blends without grafted MA showed higher crystallinity as the starch content increased. Reactive compatibilized blends with less than 20 wt% starch had higher storage modulus, indicating that the compatibility between the two phases was improved.

     

The Effect of α‐Zirconium Phosphate Nanosheets on Thermal,Mechanical, and Tribological Properties of Polyimide

In this work, to investigate the addition effect of 2D α‐zirconium phosphate (α‐ZrP) nanosheets on the properties of polyimide (PI), a series of PI/ZrP composites are synthesized by in situ polymerization. The thermal, mechanical, and tribological properties of composites strongly depend on the dispersity and distribution of α‐ZrP nanosheets in the PI matrix. The dispersed α‐ZrP can make rich interfacial interactions with PI matrix, which facilitates the transfer of external stress, heat, antiwear ability, etc., from the PI matrix to the surface of the α‐ZrP nanosheets, leading to the obvious enhancements of the thermal, mechanical, and tribological properties of the PI/ZrP composites. Specially, compared with pure PI, the tensile strength and elongation at break of the optimum sample of PI‐0.6 are increased by 13.7% and 35.7%, while its wear volume is reduced by 85%. This work provides a new paradigm for using other layered 2D nanosheets to prepare high‐performance PI‐based composite materials.     

The Impact of Cyclopropane Configuration on the Biological Activity of Cyclopropyl‐Epothilones

Two cis‐12,13‐cyclopropyl‐epothilone B variants have been synthesized, differing only in the configuration of the stereocenters at C12 and C13. The syntheses were based on a common allylic alcohol intermediate that was converted into the corresponding diastereomeric hydroxymethyl‐cyclopropanes by means of stereoselective Charette cyclopropanations. Macrocyclizations were accomplished through ring‐closing metathesis (RCM). Substantial differences between the two compounds were found with regard to microtubule binding affinity, antiproliferative activity and their effects on the cellular microtubule network. While the analogue with the cyclopropane moiety oriented in a corresponding way to the epoxide configuration in natural epothilones was almost equipotent with epothilone A, the other was significantly less active. Based on these findings, natural epothilone‐like activity of cis‐fused 12,13‐cyclopropyl‐epothilone analogues is tightly linked to the natural orientation of the cyclopropane moiety.     

The Effect of the Addition of Re and Ge on the Properties of Pt/Al2O3

The effect of Re and Ge addition to Pt/Al₂O₃ was studied. Mono-, bi- and a trimetallic catalysts were prepared and characterized by TPR, XPS, TPO and by the n-pentane, cyclohexane (CH) and n-octane reactions. It was found that the trimetallic was the most active and stable catalyst and showed selectivities to aromatics and isomers very similar to the bimetallic germanium-based catalyst.     

Impact of a Standard Rodent Chow Diet on Tissue n‐6 Fatty Acids, Δ9‐Desaturation Index,and Plasmalogen Mass in Rats Fed for One Year

Although many studies focus on senescence mechanisms, few habitually consider age as a biological parameter. Considering the effect of interactions between food and age on metabolism, here we depict the lipid framework of 12 tissues isolated from Sprague–Dawley rats fed standard rodent chow over 1 year, an age below which animals are commonly studied. The aim is to define relevant markers of lipid metabolism influenced by age in performing a fatty acid (FA) and dimethylacetal profile from total lipids. First, our results confirm impregnation of adipose and muscular tissues with medium‐chain FA derived from maternal milk during early infancy. Secondly, when animals were switched to standard croquettes, tissues were remarkably enriched in n‐6 FA and especially 18:2n‐6. This impregnation over time was coupled with a decrease of the desaturation index and correlated with lower activities of hepatic Δ5‐ and Δ6‐desaturases. In parallel, we emphasize the singular status of testis, where 22:5n‐6, 24:4n‐6, and 24:5n‐6 were exceptionally accumulated with growth. Thirdly, 18:1n‐7, usually found as a discrete FA, greatly accrued over the course of time, mostly in liver and coupled with Δ9‐desaturase expression. Fourthly, skeletal muscle was characterized by a surprising enrichment of 22:6n‐3 in adults, which tended to decline in older rats. Finally, plasmalogen‐derived dimethylacetals were specifically abundant in brain, erythrocytes, lung, and heart. Most notably, a shift in the fatty aldehyde moiety was observed, especially in brain and erythrocytes, implying that red blood cell analysis could be a good indicator of brain plasmalogens.     

The Determination of n-3 Fatty Acid Levels in Food Products Containing Microencapsulated Fish Oil Using the One-Step Extraction Method. Part 1: Measurement in the Raw Ingredient and in Dry Powdered Foods

An optimized one-step extraction and methylation method (OSE) for the determination of n-3 fatty acid levels in microencapsulated fish oil products has been described. Validation of the method for the food ingredient powder MEG-3^® (a commercial microencapsulated fish oil product manufactured by Ocean Nutrition Canada Ltd, with a gelatin shell matrix) has been demonstrated and compared to a method that combines enzymatic digestion of the shell material, gravimetric determination of released oil payload and an official method of fish oil analysis. Excellent agreement between the two methods was also achieved using a microencapsulated standard of pure ethyl palmitate. The OSE method was applied to an infant formula containing microencapsulated fish oil powder and is shown to be a valid method for such dry powdered foods.     

The Synthesis of trans‐Perhydroindolic Acids and their Application in Asymmetric Domino Reactions of Aldehyde Esters with β,γ‐Unsaturated α‐Keto Esters

(2S,3aR,7aS)‐Perhydroindolic acid, the key intermediate in the synthesis of trandolapril, and its trans‐isomers, were readily prepared. These proline‐like molecules are unique in that they contain a rigid bicyclic structure, with two hydrogen atoms trans to each other at the bridgehead carbon atoms. These molecules were used successfully as chiral organocatalysts in asymmetric domino Michael addition/cyclization reactions of aldehyde esters with β,γ‐unsaturated α‐keto esters. They proved to have excellent catalytic behavior, allowing for the synthesis of multi‐substituted, enantiomerically enriched hemiacetal esters. Under optimal conditions (using 10 mol% catalyst loading), a series of β,γ‐unsaturated α‐keto esters was examined with up to 99% de, ee and yield, respectively. Additionally, the enantiomerically enriched hemiacetal esters could be readily transformed into their corresponding bioactive pyrano[2,3‐b]pyrans (possessing a multi‐substituted bicyclic backbone).     

Influences of pre‐ordered melt structures on the crystallization behavior and polymorphic composition of β‐nucleated isotactic polypropylene with different stereo‐defect distribution

As part of continuous efforts to understand the surprising synergetic effect between β‐nucleating agent and pre‐ordered structures of isotactic polypropylene (iPP) in significant enhancement of β‐crystallization (Ordered Structure Effect, OSE), two β‐nucleated iPP with different uniformities of stereo‐defect distribution (WPP‐A and WPP‐B) were prepared, their crystallization behaviors with variation of melt structures were studied in detail. The results revealed that β‐phase can hardly form in WPP‐A (whose stereo‐defect distribution is less uniform) because of its strong tendency of α‐nucleation caused by its less uniform stereo‐defect distribution, while WPP‐B is more favorable for β‐crystallization; As fusion temperature decreases, similar variation trends of crystallization temperature and β‐phase proportion can be observed from WPP‐A and WPP‐B, indicating the occurrence of OSE behavior, which provides unsurpassed β‐nucleation efficiency and induces β‐crystallization even in WPP‐A which is less favorable for β‐crystallization; moreover, the upper and lower limiting temperatures of Region II of WPP‐A and WPP‐B are identical, suggesting the uniformity of stereo‐defect distribution has little influence on temperature window for OSE (denoted as Region II). To explore the physical nature of Region II, self‐nucleation behavior and equilibrium melting temperature of PP‐A and PP‐B were studied. The lower limiting temperatures of exclusive self‐nucleation domain of both PP‐A and PP‐B are identical with the lower limiting temperatures of Region II in OSE (168°C); moreover, the T_m⁰ of both PP‐A and PP‐B are close to their upper limiting temperatures of Region II in OSE behavior (189°C). The possible explanation was proposed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42632.