D- and N-Methyl Amino Acids for Modulating the Therapeutic Properties of Antimicrobial Peptides and Lipopeptides.

Here we designed and synthesized analogs of two antimicrobial peptides, namely C10:0-A2, a lipopeptide, and TA4, a cationic α-helical amphipathic peptide, and used non-proteinogenic amino acids to improve their therapeutic properties. The physicochemical properties of these analogs were analyzed, including their retention time, hydrophobicity, and critical micelle concentration, as well as their antimicrobial activity against gram-positive and gram-negative bacteria and yeast. Our results showed that substitution with D- and N-methyl amino acids could be a useful strategy to modulate the therapeutic properties of antimicrobial peptides and lipopeptides, including enhancing stability against enzymatic degradation. The study provides insights into the design and optimization of antimicrobial peptides to achieve improved stability and therapeutic efficacy. TA4(dK), C10:0-A2(6-NMeLys), and C10:0-A2(9-NMeLys) were identified as the most promising molecules for further studies.

Nanocomplexes based on egg white protein nanoparticles and bioactive compounds as antifungal edible coatings to extend bread shelf life.

This work is aimed to obtain nanocomplexes based on egg white protein nanoparticles (EWPn) and bioactive compounds (BC), carvacrol (CAR), thymol (THY) and trans-cinnamaldehyde (CIN), and evaluate their application as antifungal edible coatings on preservative-free breads. The nanocomplex formation was studied through stoichiometry, affinity, colloidal behavior, morphology, and encapsulation efficiency (EE, %). Rounded-shape nanocomplexes with particle sizes < 100 nm were obtained. The EE values were similar for all BC (>83%). Furthermore, the in vitro antifungal activity of the nanocomplexes was verified using the Aspergillus niger species. The nanocomplexes were applied as coatings onto the crust of preservative-free breads, which were stored for 7 days (at 25 °C). The coatings had no impact on the physicochemical properties of the bread loaves (moisture, aw, texture, and color). Finally, the coatings based on EWPn-THY and EWPn-CAR nanocomplexes showed higher antifungal efficacy, extending the bread shelf life after 7 days.

Impact of gum arabic and sodium alginate and their interactions with whey protein aggregates on bio-based films characteristics.

Two polysaccharides (PS), gum arabic (GA) and sodium alginate (SA), and whey protein concentrate (WPC) were used to design bio-based films at two ratios (RPS:WPC, 1:2 and 1:3). The effects of PS, RPS:WPC and WPC thermal treatment (unheated vs. aggregate) were determined on films characteristics. Film-forming dispersions were tested using different complementary techniques: UV-Vis spectroscopy, electrophoretic mobility, bulk rheology and confocal microscopy. PS exhibited weak associations with proteins. However, this behavior was more significative in SA/WPC systems. Rheological and optical characteristics of filmogenic suspensions were influenced by PS, RPS:WPC and WPC heat treatment. Apparent viscosity values for SA/WPC systems were 80-250 times higher than the ones obtained for GA/WPC systems. Furthermore, thickness, moisture absorption, contact angle and mechanical properties were also affected by the film design factors. GA/WPC-aggregates films showed lesser moisture absorption; however, they have higher surface polarity than those made with SA/WPC-aggregates. Moreover, SA/WPC-aggregates systems provided stronger films in comparison with the GA/WPC-aggregates ones. In addition, mechanical properties were also affected by RPS:WPC and WPC treatment. It was observed that denatured WPC and 1:3 RPS:WPC produced weaker mechanical features. Results provide useful information for the design of bio-based mixed films with tailor-made properties.

Optimization of mold wheat bread fortified with soy flour, pea flour and whey protein concentrate.

The objective of this work was to study the effect of replacing a selected wheat flour for defatted soy flour, pea flour and whey protein concentrate on both dough rheological characteristics and the performance and nutritional quality of bread. A mixture design was used to analyze the combination of the ingredients. The optimization process suggested that a mixture containing 88.8% of wheat flour, 8.2% of defatted soy flour, 0.0% of pea flour and 3.0% of whey protein concentrate could be a good combination to achieve the best fortified-bread nutritional quality. The fortified bread resulted in high protein concentration, with an increase in dietary fiber content and higher calcium levels compared with those of control (wheat flour 100%). Regarding protein quality, available lysine content was significantly higher, thus contributing with the essential amino acid requirement.

Assessment of oxidative status and genotoxicity in photocopier operators: a pilot study.

Occupational exposure to photocopiers has been indicated as being responsible for a number of health complaints, particularly effects on the respiratory, immunological, and nervous systems. In this study, we investigated oxidative and genotoxic damage in photocopier operators by assessing catalase activity (CAT), reduced vs. oxidized glutathione ratio (GSH/GSSG), level of lipid peroxidation (TBARS), damage index by Comet assay (DICA), and buccal cells with micronuclei (BCMN). Our results reveal that the TBARS levels in operators were increased (27%; p<0.05) but that no significant alterations to GSH/GSSG or CAT activity were observed. The DICA and the number of BCMN were significantly increased (134% and 100%, respectively; p<0.05) in the exposed group. There was a significant association between the time in months spent at work and DNA damage in lymphocytes (r(s) = 0.720; p<0.001) and buccal cell with MN (r(s) = 0.538; p<0.001). Because laser printers and photocopiers have become increasingly used, it is important to control human exposure using reliable biomarkers.