Chemical composition of a soybean cultivar lacking lipoxygenases (LOX2 and LOX3)

The nutrient, phytic acid, oxalate, trypsin inhibitors and isoflavones composition of a whole soy flour produced from a new cultivar (UFV-116), lacking lipoxygenases 2 and 3, compared to a conventional cultivar (OCEPAR-19) were determined. Protein and dietary fibres (total, soluble and insoluble) were similar for both cultivars. OCEPAR-19 was higher in lipids and UFV-116 in ash content (p < 0.05). Indispensable, dispensable and total aminoacid as well as Ca, K and Mg were higher for UFV-116. This cultivar also showed higher levels of phytic acid, oxalate and trypsin inhibitors (p < 0.05). Total saturated and unsaturated fatty acids were similar between them. However, palmitic and linoleic acids were higher for UFV-116 and stearic, α-linolenic and oleic acids for OCEPAR-19 (p < 0.05). The higher concentration of isoflavones in UFV-116 (p < 0.05) could provide better benefit for human health. Experimental studies are necessary to evaluate health effects of this new soybean cultivar.     

Evaluation of Norrish’s Equation for Correlating the Water Activity of Highly Concentrated Solutions of Sugars,Polyols, and Polyethylene Glycols

Norrish’s equation, a_\textw = X_\textw exp( - KX²_\texts )a_{{\text{w}}} = X_{{\text{w}}} \exp {\left( { - KX^{2}_{{\text{s}}} } \right)}, where a _w is water activity, X _w and X _s are molar fractions of water and solute, respectively, and K is the correlating constant, has been widely used to predict a _w of aqueous nonelectrolyte solutions in connection with development of intermediate moisture foods, i.e., food having a _w ≥ 0.85. Present work evaluated the ability of Norrish’s equation to model the water activity of solutions of sugars, polyols, and some polyethylene glycols, in a wide range of concentration, i.e., from low to highly concentrated solutions. For sugar and polyols, a relatively small modification of the “most accepted” literature parameters K allowed the fitting of the data for the wide range of solute concentrations corresponding to a range of a _w from 0.99 to about 0.3 for same solutes. However, a modified Norrish’s model needs to be used to model the behavior of polyethylene glycols 400 and 600 up to water activities as low as 0.5.     

G-Quadruplex in Gene Encoding Large Subunit of Plant RNA Polymerase II: A Billion-Year-Old Story

G-quadruplexes have long been perceived as rare and physiologically unimportant nucleic acid structures. However, several studies have revealed their importance in molecular processes, suggesting their possible role in replication and gene expression regulation. Pathways involving G-quadruplexes are intensively studied, especially in the context of human diseases, while their involvement in gene expression regulation in plants remains largely unexplored. Here, we conducted a bioinformatic study and performed a complex circular dichroism measurement to identify a stable G-quadruplex in the gene RPB1, coding for the RNA polymerase II large subunit. We found that this G-quadruplex-forming locus is highly evolutionarily conserved amongst plants sensu lato (Archaeplastida) that share a common ancestor more than one billion years old. Finally, we discussed a new hypothesis regarding G-quadruplexes interacting with UV light in plants to potentially form an additional layer of the regulatory network.     

A Beckwith–Wiedemann-Associated CDKN1C Mutation Allows the Identification of a Novel Nuclear Localization Signal in Human p57Kip2

p57^Kip2 protein is a member of the CIP/Kip family, mainly localized in the nucleus where it exerts its Cyclin/CDKs inhibitory function. In addition, the protein plays key roles in embryogenesis, differentiation, and carcinogenesis depending on its cellular localization and interactors. Mutations of CDKN1C, the gene encoding human p57^Kip2, result in the development of different genetic diseases, including Beckwith–Wiedemann, IMAGe and Silver–Russell syndromes. We investigated a specific Beckwith–Wiedemann associated CDKN1C change (c.946 C>T) that results in the substitution of the C-terminal amino acid (arginine 316) with a tryptophan (R316W-p57^Kip2). We found a clear redistribution of R316W-p57^Kip2, in that while the wild-type p57^Kip2 mostly occurs in the nucleus, the mutant form is also distributed in the cytoplasm. Transfection of two expression constructs encoding the p57^Kip2 N- and C-terminal domain, respectively, allows the mapping of the nuclear localization signal(s) (NLSs) between residues 220–316. Moreover, by removing the basic RKRLR sequence at the protein C-terminus (from 312 to 316 residue), p57^Kip2 was confined in the cytosol, implying that this sequence is absolutely required for nuclear entry. In conclusion, we identified an unreported p57^Kip2 NLS and suggest that its absence or mutation might be of relevance in CDKN1C-associated human diseases determining significant changes of p57^Kip2 localization/regulatory roles.     

Chemical characterisation of non-defective and defective green arabica and robusta coffees by electrospray ionization-mass spectrometry (ESI-MS)

The coffee roasted in Brazil is considered to be of low quality, due to the presence of defective coffee beans that depreciate the beverage quality. These beans, although being separated from the non-defective ones prior to roasting, are still commercialized in the coffee trading market. Thus, it was the aim of this work to verify the feasibility of employing ESI-MS to identify chemical characteristics that will allow the discrimination of Arabica and Robusta species and also of defective and non-defective coffees. Aqueous extracts of green (raw) defective and non-defective coffee beans were analyzed by direct infusion electrospray ionization mass spectrometry (ESI-MS) and this technique provided characteristic fingerprinting mass spectra that not only allowed for discrimination of species but also between defective and non-defective coffee beans. ESI-MS profiles in the positive mode (ESI(+)-MS) provided separation between defective and non-defective coffees within a given species, whereas ESI-MS profiles in the negative mode (ESI(−)-MS) provided separation between Arabica and Robusta coffees.     

Discrimination between defective and non-defective Brazilian coffee beans by their volatile profile

The coffee roasted in Brazil is considered to be of low quality, due to the presence of defective coffee beans that depreciate the beverage quality. In view of the fact that coffee flavour is directly related to the volatile compounds produced during roasting, the objective of the present study was to perform a comparative evaluation of the volatile fraction of defective (black, immature, sour) and healthy coffee beans, in order to find possible chemical markers for detection of defective coffee beans in roasted coffee. Volatiles extraction and concentration was performed by solid phase micro-extraction (SPME) of the roasted coffee headspace, using a triple phase (divinylbenzene/carboxen/polydimethylsiloxane) fiber. Analysis of the volatile profiles was performed by GC–MS. The results obtained showed that the proposed methodology was adequate for extraction, concentration and analysis of the coffees volatile profile. Several substances were identified as possible markers for differentiating black, sour and immature beans from healthy coffee beans. Statistical analysis of the data by principal components (PCA) demonstrated that the volatile profile enables the differentiation of healthy and defective coffees. The data were separated into two major groups, one represented by immature and black beans and the other by healthy and sour coffee beans. Such results indicated that black and sour beans can be associated to fermentation of immature and of healthy beans, respectively.     

Production of Bioactive Peptides from Lactic Acid Bacteria: A Sustainable Approach for Healthier Foods

Traditional fermented foods where lactic acid bacteria (LAB) are present have been associated with beneficial effects on human health, and some of those benefits are related to protein‐derived products. Peptides produced by LAB have attracted the interest of food industries because of their diverse applications. These peptides include ribosomally produced (bacteriocins) and protein hydrolysates by‐products (bioactive peptides), which can participate as natural preservatives and nutraceuticals, respectively. It is essential to understand the biochemical pathways and the effect of growth conditions for the production of bioactive peptides and bacteriocins by LAB, in order to suggest strategies for optimization. LAB is an important food‐grade expression system that can be used in the simultaneous production of peptide‐based products for the food, animal, cosmetic, and pharmaceutical industries. This review describes the multifunctional proteinaceous compounds generated by LAB metabolism and discusses a strategy to use a single‐step production process, using an alternative protein‐based media. This strategy will provide economic advantages in fermentation processes and will also provide an environmental alternative to industrial waste valorization. New technologies that can be used to improve production and bioactivity of LAB‐derived peptides are also analyzed.     

Enzyme activity during germination of different cereals: A review

The germination process increases enzymatic activity. However, this does not occur in the same way in all cereals. It depends on the type of enzyme, the cereal, and the conditions of germination. During germination, most enzymes are localized in the aleurone layer and the scutellum. Some of them, such as xylanases, proteases, and β-glucanases, are also localized in the endosperm while β-glucanases and lipases have been identified in the embryo. The maximum activity of the enzymes in most cereals start from day 4 of germination. Germination allows the hydrolysis of macromolecules and compounds like β-glucans and phytic acid. In cereals, starch is the component that presents the most morphological changes. Germination mobilizes and increases the activity of some enzymes. Temperature, steeping time, and variety are determining factors in the activation time. At higher temperatures, the enzymatic activation is generally faster; however, there are some exceptions. The use of germination could be a promising resource for modifying grain properties and increase enzymatic activity; also, this process is simple and economical.     

Anticorrosive coating based on poly(vinyl acetate) formed by electropolymerization on the copper surface

The poly(vinyl acetate) (PVAC) film was obtained by electropolymerization on the copper electrode using cyclic voltammetry performed in mixed electrolyte based on water/ethyl alcohol/acetic acid containing vinyl acetate (VAc) and benzoyl peroxide as polymerization initiator. The coatings were characterized by optical microscopy, scanning electron microscopy (SEM) and infrared (IR) spectroscopy. The corrosion was induced in hydrochloric acid solution using potentiodynamic measurements and electrochemical impedance spectroscopy (EIS). The microscopic and SEM images revealed the PVAC coating formation and IR spectroscopy confirmed that it exhibits the same characteristic bands as a standard PVAC sample. From the potentiodynamic polarization, the PVAC protective performance of 78% was computed. The EIS measurements showed the occurrence of the surface adsorbed layer with a higher impedance response to the frequency and a phase angle maximum shifted to lower values than those of uncoated samples. In addition, the VAc electropolymerization mechanism was discussed and the PVAC adsorption mechanism on the copper surface was proposed. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47320.     

Poly(hexylacrylate)Core‐poly(ethyleneglycol methacrylate)Shell nanogels as fillers for poly(2‐hydroxyethyl methacrylate) nanocomposite hydrogels

The preparation of poly(hexylacrylate)_core‐poly(ethyleneglycol methacrylate)_shell (PHA‐co‐PEGMA) nanogels, to be used as fillers in nanocomposite hydrogels, is reported. Stable nanogels with particle sizes between 90–300 nm were obtained varying the conditions of synthesis. The synthesis recipe of the nanogels could be easily scaled up. Purified and dispersed nanogels in aqueous solution were used as soft fillers for poly(2‐hydroxyethyl methacrylate) (PHEMA) hydrogels, crosslinked with ethylene glycol dimethacrylate (EGDMA). The obtained nanocomposite hydrogels exhibit a larger swelling capacity and a higher thermal stability in comparison with the non‐filled PHEMA hydrogels. Young, storage, and lost moduli, increase largely, in the better case up to 72.5% in the swollen state; while in the dry state the storage modulus increase up to 4.7 fold with a very low load on nanogels (0.64 wt%); resulting in biomaterials with improved properties with potential applications in medical devices. POLYM. ENG. SCI., 59:170–181, 2019. © 2018 Society of Plastics Engineers