Search

Yogurt rheological and textural parameters are known to have an important impact on food quality and acceptability. The paper includes the determination of the viscoelastic and textural parameters of goat's milk and cow's milk yogurt in terms of physico-chemical indices and technological properties. Two series of yogurts were prepared: series I of goat's milk and cow's milk 50:50 (5 samples) and series II of 100% goat's milk (5 samples), adding the aronia, strawberries, raspberries, peaches using classical technology. Texture parameters with higher values were obtained for yogurt of first series due to the presence of casein fractions specific to cow's milk. Added fruits to yogurt have had a positive impact on texture indices, due to contained hydrocolloids that confer thickening, stabilizing, gelling and emulsifying properties to food products. Due to the organic acids contained in fruits, the pH of yogurt is lower, so the voluminosity of casein micelle increases at lower pH value due to increased hydration, possitivly influensed the viscosity parameters. Manufacture of yogurt from goat's milk and cow's milk induced stronger yogurt gel (series I), due to a higher content of α casein in cow's milk compared to goat's milk. The viscoelastic characteristics of yogurt samples, show that G′ is higher than G′′ during the entire frequency range. The added fruits to yogurt influence the viscoelastic parameters more through some components present in their composition: The higher dry matter content in the yogurt samples with the addition of aronia, respectively indicates the higher values for the parameters G' and G'', namely for the yogurt of the second series.

Over the last decades, interest of researchers in the preparation and study of heterometallic Fe–Ln organometallic compounds has increased due to their intriguing architectures and promising applications as single molecule magnets (SMMs) that exhibit magnetic hysteresis of purely molecular origin. SMMs are fundamentally different from conventional bulk magnets because a collective long-range magnetic ordering of magnetic moments is not necessary. It is expected that SMMs can be employed in the future as the smallest magnetic memory units or in quantum computational devices. This review examines synthetic strategies and magnetic properties of Fe–Ln SMM compounds published till July 2016.

Two families of charge‐neutral heterometallic Fe‐4f coordination compounds comprising isobutyrate and amino alcoholate linkers were found to form exclusively upon ultrasonication irradiation. Under one‐pot conditions, the trinuclear precursor [Fe3O(O2CCHMe2)6(H2O)3](NO3)·2(MeCN)·2(H2O) reacts with Ln(NO3)3·xH2O or Y(NO3)3·6H2O, N‐butyldiethanolamine (bdeaH2) and NaN3 in methanol to yield the decanuclear clusters [Fe6M4(O2CCHMe2)8(N3)2(bdea)10]·n(solvent) (MIII = Y (1a·3MeOH), Gd (2a·2.5MeOH), Dy (3a·3.5MeOH·0.5H2O), Tb (4a·2MeOH), Ho (5a·2MeOH), as well as subsequently the hexanuclear compounds [Fe4M2(OH)2(O2CCHMe2)6(N3)2(bdea)4]·2(solvent) (MIII = Y (1b·2MeOH), Gd (2b·2MeOH), Dy (3b·2MeOH, 3c·2EtOH), Tb (4b·2MeOH), Er (6b·2MeOH), Tm (7b·2MeOH)). The {Fe6M4} clusters feature a wheel‐shaped architecture with the metal ions, interlinked by carboxylate and polyalcoholamine bridges, forming a saddle‐like ring. The hexanuclear {Fe4M2} clusters comprise two {Fe2M} triangles, connected via two bridging µ3‐OH– groups, which form a condensed core of metals additionally linked by deprotonated tripodal bdeaH2 ligands and bridging carboxylates. Magnetic measurements revealed predominant strong antiferromagnetic interactions within compounds 1–7 and out‐of‐phase signals for {Fe6Dy4} (3a·3.5MeOH·0.5H2O), {Fe6Tb4} (4a·2MeOH), and {Fe4Dy2} (3b·2MeOH). [ABSTRACT FROM AUTHOR]

A new μ3-oxo trinuclear chromium(III) propionate cluster, [Cr3(μ3-O)(O2CCH2CH3)6(pyr)3]NO3·0.25(H2O) (1), has been synthesized by reaction of a μ3-oxo trinuclear chromium(III) propionate precursor [Cr3(μ3-O)(O2CCH2CH3)6(H2O)3]NO3with a pyrazol ligand (pyr) and characterized by IR spectroscopy, single-crystal X-ray structure determination, and thermal analysis. Magnetic susceptibility and magnetization studies revealed antiferromagnetic exchange interactions within the trinuclear Cr(III) cluster (J = −11.9 cm−1) and determined the electronic ground state (S = ½) of the compound. [ABSTRACT FROM PUBLISHER]

A series of new octanuclear propeller-like aminoalcohol-supported Fe(iii) oxocarboxylate coordination clusters, [Fe8O3(O2CCHMe2)9(tea)(teaH)3]·MeCN·2(H2O) (1), [Fe8O3(O2CCHMe2)6(N3)3(tea)(teaH)3] (2), [Fe8O3(O2CCMe3)6(N3)3(tea)(teaH)3]·0.5(EtOH) (3), and [Fe8O3(O2CCHMe2)6(N3)3(mdea)3(MeO)3] (4) (where teaH3 = triethanolamine; mdeaH2 = N-methyldiethanolamine) has been isolated and magnetochemically analyzed combining the programs wxJFinder and CONDON in an approach to avoid overparameterization issues that are common to larger spin polytopes. Dominant antiferromagnetic exchange interactions exist in all clusters along the edges of the propellers, while moderate ferromagnetic interactions are found along the propeller axes in their {Fe8O3} metallic cores. [ABSTRACT FROM AUTHOR]

Trinuclear μ 3 -oxo-centered iron(III) isobutyrate clusters readily react with polyalcohol organic ligands under one-pot synthesis conditions. Depending on the ligand, solvent, and temperature, a range of hexa-, dodeca-, and doicosanuclear iron(III) oxo-hydroxo condensation products, isolated as (mdeaH 3 ) 2 [Fe 6 O(thme) 4 Cl 6 ]·0.5(MeCN)·0.5(H 2 O) (1), [Fe 12 O 4 (OH) 2 (teda) 4 (N 3 ) 4 (MeO) 4 ]N 3 (NO 3 ) 0.5 (MeO) 0.5 ·2.5(H 2 O) (2), [Fe 12 O 6 (teda) 4 Cl 8 ]·6(CHCl 3 ) (3), [Fe 22 O 16 (OH) 2 (O 2 CCHMe 2 ) 18 (bdea) 6 (EtO) 2 (H 2 O) 2 ]·2(EtOH)·5(MeCN)·6(H 2 O) (4), and [Fe 22 O 14 (OH) 4 (O 2 CCHMe 2 ) 18 (mdea) 6 (EtO) 2 (H 2 O) 2 ](NO 3 ) 2 ·EtOH·H 2 O (5), where tedaH 4 = N, N, N', N'-tetrakis(2-hydroxyethyl)ethylenediamine; thmeH 3 = 1,1,1-tris(hydroxymethyl)ethane; mdeaH 2 = N-methyldiethanolamine; and bdeaH 2 = N-butyldiethanolamine. Complete carboxylate metathesis in the {Fe 3 } precursor complexes by thme 3- or teda 4- and the agglomeration of the formed species under solvothermal conditions afforded carboxylate-free {Fe 6 } product (1) in MeCN/CH 2 Cl 2 or {Fe 12 } complexes (2 and 3) in MeOH/EtOH and CHCl 3 /thf, respectively (thf = tetrahydrofuran). Single-crystal X-ray diffraction analyses revealed that 1 contains a [Fe 6 O(thme) 4 Cl 6 ] 2- cluster anion with a Lindqvist-type {Fe 6 (μ 6 -O)} core motif, charge-compensated by two protonated mdeaH 3 + cations. 2 comprises a [Fe 12 O 4 (OH) 2 (teda) 4 (N 3 ) 4 (MeO) 4 ] 2+ cation with a {Fe 12 O 4 (OH) 2 } 26+ core, whereas 3 contains a charge-neutral [Fe 12 O 6 (teda) 4 (Cl) 8 ] complex with an {Fe 12 O 6 } 24+ core. Finally, employing flexible bdeaH 2 or mdeaH 2 ligands under soft reaction conditions afforded giant {Fe 22 } oxo-hydroxo complexes (4 and 5) with a central {Fe 6 } layer sandwiched between two outer {Fe 8 } groups. Magnetic studies of 1-5 revealed strong antiferromagnetic coupling between the Fe III spin centers in all clusters.

A family of wheel-shaped charge-neutral heterometallic {Fe III 4 Ln III 2 }- and {Fe III 18 M III 6 }-type coordination clusters demonstrates the intricate interplay of solvent effects and structure-directing roles of semiflexible bridging ligands. The {Fe 4 Ln 2 }-type compounds [Fe 4 Ln 2 (O 2 CCMe 3 ) 6 (N 3 ) 4 (Htea) 4 ]·2(EtOH), Ln = Dy (1a), Er (1b), Ho (1c); [Fe 4 Tb 2 (O 2 CCMe 3 ) 6 (N 3 ) 4 (Htea) 4 ] (1d); [Fe 4 Ln 2 (O 2 CCMe 3 ) 6 (N 3 ) 4 (Htea) 4 ]·2(CH 2 Cl 2 ), Ln = Dy (2a), Er (2b); [Fe 4 Ln 2 (O 2 CCMe 3 ) 4 (N 3 ) 6 (Htea) 4 ]·2(EtOH)·2(CH 2 Cl 2 ), Ln = Dy (3a), Er (3b) and the {Fe 18 M 6 }-type compounds [Fe 18 M 6 (O 2 CCHMe 2 ) 12 (Htea) 18 (tea) 6 (N 3 ) 6 ]·n(solvent), M = Dy (4, 4a), Gd (5), Tb (6), Ho (7), Sm (8), Eu (9), and Y (10) form in ca. 20-40% yields in direct reaction of trinuclear Fe III pivalate or isobutyrate clusters, lanthanide/yttrium nitrates, and bridging triethanolamine (H 3 tea) and azide ligands in different solvents: EtOH for the smaller {Fe 4 Ln 2 } wheels and MeOH/MeCN or MeOH/EtOH for the larger {Fe 18 M 6 } wheels. Single-crystal X-ray diffraction analyses revealed that 1-3 consist of planar centrosymmetric hexanuclear clusters built from Fe III and Ln III ions linked by an array of bridging carboxylate, azide, and aminopolyalcoholato-based ligands into a cyclic structure with a cavity, and with distinct sets of crystal solvents (2 EtOH per formula unit in 1a-c, 2 CH 2 Cl 2 in 2, and 2 EtOH and 2 CH 2 Cl 2 in 3). In 4-10, the largest 3d/4f wheels currently known, nearly linear Fe 3 fragments are joined via mononuclear Ln/Y units by a set of isobutyrates and amino alcohol ligands into virtually planar rings. The magnetic properties of 1-10 reveal slow magnetization relaxation for {Fe 4 Tb 2 } (1d) and slow relaxation for {Fe 4 Ho 2 } (1c), {Fe 18 Dy 6 } (4), and {Fe 18 Tb 6 } (6).