22 research outputs found
Antioxidants Properties and Effect of Processing Methods on Bioactive Compounds of Legumes
Extensive research has proven that fruits and vegetables contribute significantly to the body supply of bioactive compounds due to their antioxidant activity to protect organisms against harmful effects of oxygen radicals. A special case is the legumes that are also rich source of proteins, dietary fiber, micronutrients, and bioactive phytochemicals. Many legume species are still an irreplaceable source of dietary proteins for humans, especially in the mainly vegetarian diets of developing countries. Incorporation of leguminous seeds into the human diet can offer protective effects against chronic diseases because they contain a number of bioactive substances including phenolics that can increase protein digestibility and mineral bioavailability. However, technological processing and seed germination can impact the levels of natural endogenous antioxidants (e.g., phenolics, tocopherols; vitamin C) in leguminous seeds. Therefore, this chapter is a review about reports of antioxidant properties and their relationship with their total phenolic content of the most commonly consumed legumes. Researches about changes in the content of natural antioxidants during technological processing are included as well as some clinical reports concerning to the health benefits offered by legumes of higher consumption
Detection of Cyanuric Acid and Melamine in Infant Formula Powders by Mid-FTIR Spectroscopy and Multivariate Analysis
Chemometric methods using mid-FTIR spectroscopy were developed in order to reduce the time of study of melamine and cyanuric acid in infant formulas. Chemometric models were constructed using the algorithms Partial Least Squares (PLS1, PLS2) and Principal Component Regression (PCR) in order to correlate the IR signal with the levels of melamine or cyanuric acid in the infant formula samples. Results showed that the best correlations were obtained using PLS1 (R2: 0.9998, SEC: 0.0793, and SEP: 0.5545 for melamine and R2: 0.9997, SEC: 0.1074, and SEP: 0.5021 for cyanuric acid). Also, the SIMCA model was studied to distinguish between adulterated formulas and nonadulterated samples, giving optimum discrimination and good interclass distances between samples. Results showed that chemometric models demonstrated a good predictive ability of melamine and cyanuric acid concentrations in infant formulas, showing that this is a rapid and accurate technique to be used in the identification and quantification of these adulterants in infant formulas
Morphological and Physicochemical Characterization of Agglomerates of Titanium Dioxide Nanoparticles in Cell Culture Media
Titanium dioxide nanoparticles (TiO2 NP) are possible carcinogenic materials (2B-IARC) and their toxicity depends on shape, size, and electrical charge of primary NP and on the system formed by NP media. The aim of this work was to characterize agglomerates of three TiO2 NP by evaluating their morphometry, stability, and zeta potential (ζ) in liquid media and their changes with time. Sizes of agglomerates by dynamic light scattering (DLS) resulted to be 10–50 times larger than those obtained by digital image analysis (DIA) given the charged zone around particles. Fractal dimension (FD) was highest for agglomerates of spheres and belts in F12K, and in E171 in FBS media. E171 and belts increased FD with time. At time zero, using water as dispersant FD was larger for agglomerates of spheres than for of E171. Belts suspended in water had the smallest values of circularity (Ci) which was approximately unchanged with time. All dispersions had ζ values around −30 mV at physiological pH (7.4) and dispersions of NP in water and FBS showed maximum stability (Turbiscan Lab analysis). Results help in understanding the complex NP geometry-size-stability relationships when performing in vivo and in vitro environmental-toxicity works and help in supporting decisions on the usage of TiO2 NP
Exploration adhesion properties of Liquorilactobacillus and Lentilactobacillus isolated from two different sources of tepache kefir grains.
Due to the distinctive characteristics of probiotics, it is essential to pinpoint strains originating from diverse sources that prove efficacious in addressing a range of pathologies linked to dysfunction of the intestinal barrier. Nine strains of lactic acid bacteria were isolated from two different sources of tepache kefir grains (KAS2, KAS3, KAS4, KAS7, KAL4, KBS2, KBS3, KBL1 and KBL3), and were categorized to the genus Lacticaseibacillus, Liquorilactobacillus, and Lentilactobacillus by 16S rRNA gene. Kinetic behaviors of these strains were evaluated in MRS medium, and their probiotic potential was performed: resistance to low pH, tolerance to pepsin, pancreatin, bile salts, antibiotic resistance, hemolytic activity, and adhesion ability. KAS7 strain presented a higher growth rate (0.50 h-1) compared with KAS2 strain, who presented a lower growth rate (0.29 h-1). KBS2 strain was the only strain that survived the in vitro stomach simulation conditions (29.3%). Strain KBL1 demonstrated significantly higher viability (90.6%) in the in vitro intestine simulation conditions. Strain KAS2 demonstrated strong hydrophilic character with chloroform (85.6%) and xylol (57.6%) and a higher percentage of mucin adhesion (87.1%). However, strains KBS2 (84.8%) and KBL3 (89.5%) showed the highest autoaggregation values. In terms of adhesion to the intestinal epithelium in rats, strains KAS2, KAS3 and KAS4 showed values above 80%. The growth of the strains KAS2, KAS3, KAS4, KBS2, and KBL3 was inhibited by cefuroxime, cefotaxime, tetracycline, ampicillin, erythromycin, and cephalothin. Strains KBS2 (41.9% and 33.5%) and KBL3 (42.5% and 32.8%) had the highest co-aggregation values with S. aureus and E. coli. The results obtained in this study indicate that lactic acid bacteria isolated from tepache can be considered as candidates for potentially probiotic bacteria, laying the foundations to evaluate their probiotic functionality in vivo and thus to be used in the formulation of functional foods
Squalene-Rich Amaranth Oil Pickering Emulsions Stabilized by Native α-Lactalbumin Nanoparticles
The stabilization of Pickering emulsions by nanoparticles has drawn great interest in the field of food science and technology. In this study, α-Lactalbumin nanoparticles prepared by the desolvation and cross-linking method from protein solutions with initial pH values of 9 and 11 were used to stabilize squalene-rich amaranth oil Pickering o/w emulsions. The effect of different concentrations of nanoparticles on the size, size distribution, ζ potential, and emulsion stability was evaluated using dynamic light scattering, electron microscopy, and light backscattering. Dependence of the emulsions’ droplet size on the nanoparticle concentration was observed, and the critical coverage ratio was reached when 5–10% nanoparticles concentration was used. Our findings suggest that α-LA nanoparticles at a 10% concentration can be used as novel stabilizers for Pickering emulsions to provide protection for beneficial lipophilic bioactive compounds. This is the first time that native α-LA nanoparticles have been used as stabilizers of Pickering emulsions
Protective Effect of Alginate Microcapsules with Different Rheological Behavior on <i>Lactiplantibacillus plantarum</i> 299v
Alginate encapsulation is a well-known technique used to protect microorganisms from adverse conditions. However, it is also known that the viscosity of the alginate is dependent on its composition and degree of polymerization and that thermal treatments, such as pasteurization and sterilization, can affect the structure of the polymer and decrease its protection efficiency. The goal of this study was to evaluate the protective effect of encapsulation, using alginates of different viscosities treated at different temperatures, on Lactiplantibacillus plantarum 299v under in vitro gastrointestinal conditions and cold storage at 4 °C and −15 °C, respectively. Steady- and dynamic-shear rheological tests were used to characterize the polymers. Thermal treatments profoundly affected the rheological characteristics of alginates with high and low viscosity. However, the solutions and gels of the low-viscosity alginate were more affected at a temperature of 117 °C. The capsules elaborated with high-viscosity alginate solution and pasteurized at 63 °C for 30 min provided better protection to the cells of L. plantarum 299v under simulated gastrointestinal and cold storage conditions
Removal of Methylene Blue from Aqueous Solutions by Using Nance (Byrsonima crassifolia) Seeds and Peels as Natural Biosorbents
Contamination of effluents with chemicals is a serious problem that impacts human health. Methylene blue is a cationic dye found frequently in industrial and urban sewages. In this work, dried grinded seeds and peels of nance were used as biosorbents in aqueous solutions at pH 7 and 10 (simulating urban and textile effluents) finding that Langmuir and Freundlich isotherms adequately described the sorption. Adsorption efficiencies were larger than 98% in all cases and slightly lower at pH 7 due to the closeness with the point of zero charge (pzc) of seeds and peels of nance (5.96 and 3.42, respectively). In all cases, Langmuir adsorption was favorable (RLa < 1), and Gibbs free energy of adsorption was negative indicating spontaneity, and since these values were larger than −80 but lower than 0 kJ/mol, the MB removal process was mainly due to physical interactions, a characteristic of physical adsorption. No significant differences were found amongst bulk mass transfer coefficients for the adsorption of both sorbents, indicating that both bioadsorbents had the same hydrodynamic and driving forces as well as depicted similar MB-adsorbent affinities. Interaction of MB with adsorbents was corroborated by FTIR spectroscopy, and the sorption was evidenced by scanning electron microscopy and image analysis which indicated that both adsorbents had fractal structures
S1 Graphical abstract -
Due to the distinctive characteristics of probiotics, it is essential to pinpoint strains originating from diverse sources that prove efficacious in addressing a range of pathologies linked to dysfunction of the intestinal barrier. Nine strains of lactic acid bacteria were isolated from two different sources of tepache kefir grains (KAS2, KAS3, KAS4, KAS7, KAL4, KBS2, KBS3, KBL1 and KBL3), and were categorized to the genus Lacticaseibacillus, Liquorilactobacillus, and Lentilactobacillus by 16S rRNA gene. Kinetic behaviors of these strains were evaluated in MRS medium, and their probiotic potential was performed: resistance to low pH, tolerance to pepsin, pancreatin, bile salts, antibiotic resistance, hemolytic activity, and adhesion ability. KAS7 strain presented a higher growth rate (0.50 h-1) compared with KAS2 strain, who presented a lower growth rate (0.29 h-1). KBS2 strain was the only strain that survived the in vitro stomach simulation conditions (29.3%). Strain KBL1 demonstrated significantly higher viability (90.6%) in the in vitro intestine simulation conditions. Strain KAS2 demonstrated strong hydrophilic character with chloroform (85.6%) and xylol (57.6%) and a higher percentage of mucin adhesion (87.1%). However, strains KBS2 (84.8%) and KBL3 (89.5%) showed the highest autoaggregation values. In terms of adhesion to the intestinal epithelium in rats, strains KAS2, KAS3 and KAS4 showed values above 80%. The growth of the strains KAS2, KAS3, KAS4, KBS2, and KBL3 was inhibited by cefuroxime, cefotaxime, tetracycline, ampicillin, erythromycin, and cephalothin. Strains KBS2 (41.9% and 33.5%) and KBL3 (42.5% and 32.8%) had the highest co-aggregation values with S. aureus and E. coli. The results obtained in this study indicate that lactic acid bacteria isolated from tepache can be considered as candidates for potentially probiotic bacteria, laying the foundations to evaluate their probiotic functionality in vivo and thus to be used in the formulation of functional foods.</div
Morphological identification by Gram stain and shape of the colony growing in MRS medium.
Morphological identification by Gram stain and shape of the colony growing in MRS medium.</p
Growth and acidification on homofermentative—heterofermentative differential (HHD) agar medium.
Growth and acidification on homofermentative—heterofermentative differential (HHD) agar medium.</p