Lipidology, Volume 1, Issue 1 (June 2024) – 4 articles

The individual viscoelastic responses of gluten proteins and their lipid-removed counterparts were studied under mixing deformations and small, medium, and large deformations selected in the Large Amplitude Oscillatory Shear (LAOS) sweeps. During Farinograph mixing, gliadin reached the 500 BU consistency line after 3.6 ± 0.4 min, while the highest consistency recorded for lipid-removed gliadin was 268 ± 8.4 BU, suggesting a reduction in the water absorption of gliadin in the absence of lipids. The affinity of glutenin to water increased in the absence of lipids, as development time was reached 11 min earlier for lipid-removed glutenin. Under small LAOS strains, tanδ of gliadin remained constant with the removal of lipids, while glutenin’s elasticity decreased (tanδ increased) in the absence of lipids at high frequencies. Intracycle strain-stiffening behavior (e₃/e₁ > 0) of gliadin increased under medium deformations with high frequency and decreased under low-frequency large deformations as lipids were removed, while this response decreased for glutenin with the removal of lipids only under high-frequency medium and large deformations. Under large LAOS strains, the clockwise rotation of the Lissajous–Bowditch curves for gliadin in the absence of lipids suggested higher intercycle strain-softening and shear-thinning, while the counter-clockwise rotation of the curves for glutenin in the absence of lipids suggested lower intercycle strain-softening and shear-thinning. These results revealed the influence of endogenous lipids on the viscous-dominated response of gliadin and to the elastic-dominated response of glutenin, while balancing the intracycle strain-stiffening behaviors of these gluten proteins especially under large deformations. Full article

Edible oils have commercial and nutritional value due to the presence of essential fatty acids. They can be consumed fresh in the form of capsules known as nutraceuticals. The quality of such products is of interest to the consumer. In this context, this study describes a method based on high-resolution nuclear magnetic resonance (NMR) and Fourier-transform mid-infrared spectroscopic analysis (FTIR), combined with statistical analyses, to differentiate different edible oils used as nutraceuticals in Brazil by fatty acid content. Through the analysis of ¹H NMR spectra, the levels of saturated and unsaturated fatty acids in edible oils were characterized and quantified. Statistical analysis of the data confirmed the real distinctions between nutraceutical raw materials, with emphasis on ω-9, ω-6, and ω-3 fatty acids. The analytical approach presented also demonstrates the potential to identify the origin (animal or vegetable) of edible oils used as nutraceuticals. Full article

The precise role of protein–lipid interactions in protein translocation is, after almost four decades of research, still a matter of debate. The experimental evidence, as described in the literature, indicates that (anionic) phospholipids play a role in numerous events in protein translocation; however, its meaning and relevance are still a matter of debate. This study tries to fill some missing links in the experimental evidence by means of in silico experiments. The study presented here indicates not only that there is a direct signal sequence–phospholipid interaction but also that the corresponding signal peptides can translocate additional amino acids across a pure lipid membrane. Furthermore, results are presented when it comes to the extent of anionic phospholipids’ dependence on this process. The correlations between the in silico results of pure signal peptide–phospholipid interactions and the observed experimental trends in the overall protein translocation effects are at least remarkable. The results emphasize that new models for protein translocation will have to be developed to take all these and previous experimental data into account. Full article