Effects of Hexane on Protein Profile,Solubility and Foaming Properties of Defatted Proteins Extracted from Tenebrio molitor Larvae

Inclusion of edible insects in human diets is increasingly promoted as a sustainable source of proteins with high nutritional value. While consumer acceptability remains the main challenge to their integration into Western food culture, the use of edible insects as meal and protein concentrate could decrease neophobia. The defatting of edible insects, mostly done with hexane, is the first step in producing protein ingredients. However, its impact on protein profiles and techno-functionality is still unclear. Consequently, this study compares the protein profiles of hexane-defatted and non-hexane-defatted yellow mealworm (Tenebrio molitor) meals and protein extracts, and evaluates the impact of hexane on protein solubility and foaming properties. Results showed that profiles for major proteins were similar between hexane-defatted and non-defatted samples, however some specific content differences (e.g., hexamerin 2) were observed and characterized using proteomic tools. Protein solubility was markedly lower for T. molitor meals compared to protein extracts. A large increase in the foaming capacity was observed for defatted fractions, whereas foam stability decreased similarly in all fractions. Consequently, although the hexane-defatting step was largely studied to produce edible insect protein ingredients, it is necessary to precisely understand its impact on their techno-functional properties for the development of food formulations.     

Detection of refined olive oil adulteration with refined hazelnut oil by employing NMR spectroscopy and multivariate statistical analysis

NMR spectroscopy was employed for the detection of adulteration of refined olive oil with refined hazelnut oil. Fatty acids and iodine number were determined by ¹H NMR, whereas ³¹P NMR was used for the quantification of minor compounds including phenolic compounds, diacylglycerols, sterols, and free fatty acids (free acidity). Classification of the refined oils based on their fatty acids content and the concentration of their minor compounds was achieved by using the forward stepwise canonical discriminant analysis (CDA) and the classification binary trees (CBTs). Both methods provided good discrimination between the refined hazelnut and olive oils. Different admixtures of refined olive oils with refined hazelnut oils were prepared and analyzed by ¹H NMR and ³¹P NMR spectroscopy. Subsequent application of CDA to the NMR data allowed the detection of the presence of refined hazelnut oils in refined olive oils at percentages higher than 5%. Application of the non-linear classification method of the binary trees offered better possibilities of measuring adulteration of the refined olive oils at a lower limit of detection than that obtained by the CDA method.     

Use of fat suppression in R₂ relaxometry with MRI for the quantification of tissue iron overload in beta-thalassemic patients

Purpose

To assess the performance and results of R₂ relaxometry using a fat-suppressed (FS) multiecho sequence and compare these to conventional R₂ relaxometry in estimating tissue iron overload.

Materials and Methods

Relaxation rate values (R₂=1/T2) of the liver, spleen, pancreas and vertebral bone marrow (VBM) were estimated in 21 patients with β-thalassemia major, using a respiratory-triggered 16-echo Carr-Purcell-Meiboom-Gill (CPMG) spin-echo sequence before (R₂) and after (R₂ FS) the application of chemically selective fat suppression.

Results

Hepatic and splenic R₂ FS values correlated with respective R₂ values (r=0.98 and r=0.96, P<.001), whereas correlations between R₂ FS and R₂ values for pancreas and VBM were not statistically significant. Bland–Altman plots show disagreement between R₂ and R₂ FS values, particularly for pancreas and VBM. Hepatic, pancreatic and VBM R₂ FS values correlated with serum ferritin (r=0.88, P<.001; r=0.51, P<.003; and r=0.75, P<.002, respectively). Hepatic R₂ FS values correlated with splenic R₂ FS (r=0.77, P<.03), pancreatic R₂ FS (r=0.61, P<.006) and VBM R₂ FS values (r=0.70, P<.001), whereas pancreatic R₂ FS values correlated also with VMB R₂ FS values. On the contrary, among the R₂ values of the above tissues, obtained without fat suppression, only hepatic R₂ values correlated with serum ferritin, whereas no correlation was documented between hepatic and pancreatic or VBM R₂ values. The application of fat suppression did not improve breathing or flow artifacts.

Conclusion

Application of fat suppression in the standard CPMG sequence improved the capability of MRI in noninvasive quantification of iron, particularly in lipid-rich tissues, such as vertebral bone marrow (VBM) and pancreas.     

Preparation of titanium‐containing polymeric foam for inertial confinement fusion target

In the framework of the increasing need for metal‐doped polymer materials for inertial confinement fusion targets, we report the preparation of low‐density titanium‐containing materials. For this purpose, we developed a new monomer based on hydroxyl and oxime chelation: Ti₃(5‐vinylsalicylaldoximato)₂(Oi‐Pr)₈. We report here the synthesis, characterization and first results of polymerization of this new titanium‐containing monomer. Copyright © 2013 John Wiley & Sons, Ltd.     

First enantioselective synthesis of 4-aminoalcohol quinoline derivatives through a regioselective SN2 epoxide opening mechanism

Mefloquine derivatives, contrary to chloroquine derivatives have not been widely studied to date. Consequently, mefloquine and its derivatives still remain very attractive synthetic targets. Although mefloquine is usually used clinically as a racemic mixture, some studies have shown that its (+)-enantiomer is more potent than the (−)-enantiomer. Moreover, the (−)-enantiomer is responsible for side effects due to reaction with the central nervous system adenosine receptors, while the (+)-enantiomer does no bind at this binding site. Recently, different libraries of racemic 4-aminoalcohol quinolines showed interesting antimalarial activities. Herein, we describe an enantiopure synthetic and straightforward route to prepare pure enantiomer 4-aminoalcohol quinoline derivatives through a 4-oxirane key-intermediate. A regioselective S_N2 ring opening of this epoxide, by diverse amines, allows us to obtain the corresponding (R) or (S) 4-aminoquinolines with good yields and enantiomeric excesses generally superior to 92%. The reported methodology appears suitable for the synthesis of a large number of pure enantiomer 4-aminoalcohol quinoline derivatives.     

Folding Assessment of Incorporation of Noncanonical Amino Acids Facilitates Expansion of Functional-Group Diversity for Enzyme Engineering

Protein design is limited by the diversity of functional groups provided by the canonical protein „building blocks“. Incorporating noncanonical amino acids (ncAAs) into enzymes enables a dramatic expansion of their catalytic features. For this, quick identification of fully translated and correctly folded variants is decisive. Herein, we report the engineering of the enantioselectivity of an esterase utilizing several ncAAs. Key for the identification of active and soluble protein variants was the use of the split-GFP method, which is crucial as it allows simple determination of the expression levels of enzyme variants with ncAA incorporations by fluorescence. Several identified variants led to improved enantioselectivity or even inverted enantiopreference in the kinetic resolution of ethyl 3-phenylbutyrate.     

Electronically excited states and visible region photodissociation spectroscopy of Au(m)(+) . Ar(n) clusters (m=7-9): molecular dimensionality transition?

Photodissociation spectra were determined for Au(m)(+) . Ar(n) (m=7; n=0-3 and m=8,9; n=0,1) in the photon energy range of 2.14-3.02 eV. Experimental data were compared with predictions of dipole allowed transitions using time-dependent density functional theory (TDDFT) as applied to cluster structures from both DFT (B3-LYP functional) and ab initio calculations at the MP2 level. Argon adduct formation does not significantly perturb the bare metal cluster core structure, but it does change the metal cluster spectrum for highly symmetric cluster structures. The photodissociation spectra are consistent with a transition from planar to three-dimensional gold cluster core geometries between m=7 and m=8 for both n=0 and 1. TDDFT predictions for favored isomers describe experimental absorption features to within +/-0.25 eV. We also discuss size-dependent trends in TDDFT transition energies for the lowest energy two- and three-dimensional structures of Au(m)(+)(m=3-9).     

Optimized operating rules for short-term hydropower planning in a stochastic environment

Computational Management Science - To operate a large-scale hydropower production system in an ever-changing environment, operating rules are a convenient way of communication between short-term...