Antimicrobial performance of potassium sorbate supported in tapioca starch edible films

The release and antimicrobial activity of potassium sorbate (KS) supported in tapioca starch–glycerol edible films prepared by different gelatinization/drying techniques against Zygosaccharomyces bailii was studied. Antimicrobial release in liquid media of different pHs (3.0–6.0) could be approximated to a pseudo first-order kinetic model and was almost accomplished after 30 min. Filmmaking method involving slow gelatinization and drying rate resulted in the highest fraction of KS released at equilibrium. Rate constant was higher when pH of the receiving media was 4.5 and fast gelatinization/fast drying had been used. The effectiveness of the preservative released for controlling the microbial growth depended on the pH of the receiving media, being higher at pH 3.0. No effect of filmmaking method was observed. In relation to film effectiveness as a barrier to contamination, it was observed that the preservative was available to prevent an external Z. bailii contamination and also to control yeast growth in an acidified (pH 4.5) high water activity (a _w = 0.980) semisolid product.     

Effect of drying temperature on the quality of dried bananas cv. prata and d’água

The effect of drying temperature (60 and 70 °C) on the chemical characterization, sensorial evaluation and microbiological quality of dried bananas obtained in a forced-air drying chamber under constant air flow rate (30 m³/h) was studied. The results showed that drying did not affect the chemical composition and the products were in good sanitary conditions. The sensorial analysis showed that lower drying temperatures produced better-accepted products and that under these conditions products obtained using the banana cv. d’água showed a superior texture to that of the standard.     

Effect of genotype,maturity stage and post‐harvest storage on phenolic compounds,carotenoid content and antioxidant capacity,of Andean mashua tubers (Tropaeolum tuberosum Ruiz & Pavón)

The total phenolics, anthocyanins, flavan 3‐ols, carotenoids and antioxidant capacity of mashua (Tropaeolum tuberosum Ruiz & Pavón) tubers from 10 yellow and purple cultivars were determined at different maturity stages (5–7.5 months after planting) and sunning post‐harvest storage periods (7–35 days). Both the antioxidant capacity (ORAC and ABTS assays) and the content of the bioactive compounds tested varied markedly between cultivars. Purple varieties reached the highest antioxidant capacity during tuber development (271–446 µmol Trolox equiv g^?1 DM, ORAC assay). The kinetics of accumulation or disappearance of the bioactive compounds tested during maturation was dependent both on the cultivar and on the compound considered. For anthocyanins, there was a marked increase during maturation in all the purple cultivars. During the sunning post‐harvest storage, the changes in antioxidant capacity (ABTS assay) and content of the bioactive compounds tested also varied between cultivars. A marked decrease in anthocyanins was observed for the anthocyanin‐containing cultivars. In general, the correlation between antioxidant capacity and the content of bioactive compounds varied markedly between cultivars. Antioxidant capacity in purple varieties correlated with total phenolics or flavan 3‐ols while only in some yellow varieties antioxidant capacity correlated with total phenolics. Copyright © 2007 Society of Chemical Industry     

Sensory Characterization and Consumer Preference Mapping of Fresh Sausages Manufactured with Goat and Sheep Meat

The main objective of this study was the sensory characterization, by a taste and a consumers’ panel, of fresh sausages from 140 culled goats and 140 culled ewes. Species and type of preparation effects were studied. All data were previously analyzed by analysis of variance. Taste panel data were analyzed by a Generalized Procrustes Analysis (GPA). Consumers’ panel data were analyzed by Preference Mapping. The 1st 2 factors explained 88.22% of total variation in GPA. Different sausages samples were perfectly differentiated by assessors. Goat sausages have been considered harder, more fibrous, and less juicy than sheep sausages. The panelists observed that sheep sausages without paprika had greater intensity of flavor, tasted spicy, and had an off‐odor, while goat sausages with paprika were considered sweeter. Consumers’ panel did not show any preference for the different types of sausages. This means that all types of sausages can have market opportunity.     

Phenols,Flavonoids, and Antioxidant and Antibacterial Activity of Leaves and Stem Bark of Morus Species

Leaves and stem bark composition from Morus species (M. alba var. alba, M. alba var. rosa and M. rubra) was evaluated for its antioxidant and antimicrobial activities in order to enhance its therapeutic uses. Total phenolics and flavonoids contents were estimated in hydromethanolic and aqueous extracts. Results showed highest content in M. rubra leaves aqueous extract (1129 mg gallic acid equivalent/100 g dry weight and 816 mg gallic acid equivalent/100 g dry weight, respectively). Using 2,2-diphenyl-1-picrylhydrazyl assay, the highest antioxidant activity was obtained in aqueous stem barks extracts. M. alba var. alba has an IC₅₀ of 2.84 mg/ml and the IC₅₀ value of M. rubra was the highest (4.78 mg/ml). ABTS^.+ (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) method and reducing power assay were used to confirm the results from the 2,2-diphenyl-1-picrylhydrazyl test. All extracts expressed considerable free radical-scavenging properties. Hydromethanolic and aqueous extracts were tested against Staphylococcus aureus, Enterococcus feacalis, Staphylococcus epidermis, Escherichia coli, and Salmonella Typhimurium bacteria. Hydromethanolic stem bark extracts have the highest antimicrobial activities, and it may be a good antimicrobial agent for human gastrointestinal infections. This plant could be used as an additive to foods and also as a possible source to obtain new and effective herbal medicines to treat infections of multi-drug resistant strains of microorganisms.     

Three-component competitive adsorption model for fixed-bed and moving-bed granular activated carbon adsorbers. Part II. Model parameterization and verification

COMPSORB-GAC is a 3-component competitive adsorption kinetic model for granular activated carbon (GAC) adsorbers that was developed in Part I of this study, including a proposed procedure for determining model parameters in natural water applications with background natural organic matter (NOM). Part II of this study demonstrates the proposed parameterization procedure and validates the modeling approach by comparing predictions with experimental breakthrough curves at multiple empty-bed contact times for both fixed-bed and moving-bed reactors. The parameterization procedure consists of a set of independent, short-term experimental tests with fresh and batch preloaded adsorbents and then data fitting using both classic and recently developed theoretical expressions. The model and parameterization procedure simplifies NOM into two fictive fractions (pore-blocking and strongly competing) and incorporates three competitive effects that vary both temporally and axially in a GAC column (direct competition for sites, intraparticle pore blockage, and external surface pore blockage). With all three competitive mechanisms accounted for, the model could accurately predict breakthrough profiles for column lengths and durations that were much longer than those used for model parameterization. Model predictions that ignored one or more of the competitive mechanisms showed that each mechanism was important for different regions of the breakthrough curve. The external surface pore-blockage effect was predominant for the prediction of early breakthrough data, whereas direct competition for sites and intraparticle pore blockage were prevalent when predicting higher breakthrough levels and data later in the column run.     

Cell Type-Specific Induction of Inflammation-Associated Genes in Crohn’s Disease and Colorectal Cancer

Based on the rapid increase in incidence of inflammatory bowel disease (IBD), the identification of susceptibility genes and cell populations contributing to this condition is essential. Previous studies suggested multiple genes associated with the susceptibility of IBD; however, due to the analysis of whole-tissue samples, the contribution of individual cell populations remains widely unresolved. Single-cell RNA sequencing (scRNA-seq) provides the opportunity to identify underlying cellular populations. We determined the enrichment of Crohn’s disease (CD)-induced genes in a publicly available Crohn’s disease scRNA-seq dataset and detected the strongest induction of these genes in innate lymphoid cells (ILC1), highly activated T cells and dendritic cells, pericytes and activated fibroblasts, as well as epithelial cells. Notably, these genes were highly enriched in IBD-associated neoplasia, as well as sporadic colorectal cancer (CRC). Indeed, the same six cell populations displayed an upregulation of CD-induced genes in a CRC scRNA-seq dataset. Finally, after integrating and harmonizing the CD and CRC scRNA-seq data, we demonstrated that these six cell types display a gradual increase in gene expression levels from a healthy state to an inflammatory and tumorous state. Together, we identified cell populations that specifically upregulate CD-induced genes in CD and CRC patients and could, therefore, contribute to inflammation-associated tumor development.     

Hydrothermally treated chitosan spontaneously forms water-soluble spherical particles stable at a wide pH range

The authors report the spontaneous formation of water-soluble chitosan-tartaric acid (CS-TA) spherical particles. Particles are formed by heating chitosan in the presence of tartaric acid under hydrothermal conditions. Tartaric acid serves as an ionic cross-linker, a depolymerizing agent, and a particle stabilizer in aqueous phase. The CS-TA particles exhibit superior colloidal stability at a wide pH range due to their surface charge tunability, which is due to the colocalization of surface hydroxyl, amine, and carboxyl groups. At physiological pH condition, particles have zwitterionic structure as determined by the zeta potential measurements. Still, CS-TA maintains colloidal stability at neutral pH due to the abundance of surface hydroxyl groups. As a proof-of-concept study, the CS-TA particles were labeled with a model insoluble cargo (fluorescein isothiocyanate [FITC]) to demonstrate their capacity for solubilizing hydrophobic drugs. The CS-TA/FITC conjugates were found to remain well dispersed at neutral pH, while maintaining FITC fluorescence properties.     

Magnetic polystyrene–palygorskite nanocomposite obtained by heterogeneous phase polymerization to apply in the treatment of oily waters

Water contaminated by oil poses challenges to the management of water resources. Magnetic nanoparticles has been issue of different potential applications including remotion oil from water. Magnetic polystyrene–palygorskite nanocomposites were prepared by a heterogeneous phase polymerization for the removal of organic contaminants from water. The organo‐Fe₃O₄‐palygorskite nanoparticles were coated with polystyrene, forming water repellent and oil absorbing surfaces to promote the removal of oil from the surfaces of nanocomposites by applying an external magnetic field. X‐ray fluorescence, X‐ray diffraction, scanning electron microscopy, zeta potential and size distribution measurement, surface area determination by BET, density measurement by He pycnometry, carbon grade determination, thermogravimetric analysis, Fourier‐transform infrared spectroscopy, Raman spectroscopy, and evaluation of hydrophobicity by contact angle were used to characterize the nanoparticles. The magnetic nanocomposite obtained showed excellent hydrophobicity, around 78° contact angle. In addition, oil removal capability tests were also performed, according to which the preliminary results indicated removal of approximately 98% of oil in synthetic oily water samples. The oil–water separation using this magnetic nanocomposite provides a promising alternative strategy for water treatment. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46162.