A washed-curd goat's cheese as a vehicle for delivery of a potential probiotic bacterium: Lactobacillus delbrueckii subsp. lactis UO 004

This study characterizes the probiotic properties of Lactobacillus delbrueckii subsp. lactis UO 004 and examines its suitability for making cheese. This strain was isolated from infant feces and shows interesting features, such as acid and bile tolerance, adherence to intestinal epithelial cells, and inhibition of the growth of certain enteropathogens, that support its potential use as a probiotic strain. In this regard, the suitability of a washed-curd cheese (Vidiago type) made with goat's milk as a delivery system for this probiotic strain was assessed. Lactobacillus delbrueckii subsp. lactis UO 004 was incorporated into a starter culture (IPLA 001). Changes in the overall composition of control and experimental cheeses were determined during ripening through bacteriological, chemical, high-performance liquid chromatography, and gas chromatography analyses. Slight changes in the gross composition and appreciable differences in the flavor compounds profile were observed between control and experimental cheeses. This strain was capable of surviving at high cell numbers (10(8) to 10(9) CFU/g) in cheeses after 28 days of ripening without adversely affecting sensory criteria or appearance of the cheese, thus satisfying the criteria for a probiotic food product.     

Interaction of Chitosan with mono and di- valent anions in aqueous solution studied by cyclic voltammetry at a water/1,2-dichloroethane interface

The interaction of the cationic polyelectrolyte chitosan (CHI), of different molecular weights, with two anions, picrate (Pi^?) and eosin (Eo^2?), in water was analyzed at pH 2.50 and 5.00. For this purpose the anions transfer current across a water/1,2-dichloroethane interface was employed to quantify anions concentration in absence or in presence of CHI. When CHI was added in increasing amounts to aqueous solutions containing Eo^2? or Pi^?, a gradual decrease in current values was observed, evidencing the binding of the anions to the polymer. This effect was more important at low pH values and for CHI with the highest molecular weight. From the results it is concluded that the interaction Eo^2?-CHI is stronger than the corresponding to Pi^?, probably due to the higher negative charge, and therefore the more pronounced hydrophilic nature of the first anion, which could lead to favour the electrostatic interactions with the cationic polyelectrolyte.     

Effect of prickly pear and algarrobo pod syrup coatings on consumer acceptance and stability of roasted almonds

BACKGROUND: The objective of this study was to evaluate the oxidative stability of roasted almonds coated with prickly pear and ‘algarrobo’ pod syrups and the effect of these coatings on consumer acceptance. RESULTS: Prickly pear syrup had higher moisture, proteins, ashes and lipids, and lower carbohydrate content, than algarrobo pod syrup. Phenolics and antioxidant activity such as inhibition percentages of diphenyl picryl hydrazyl radical were higher in prickly pear syrup than algarrobo pod syrup. Roasted almonds had higher protein and lipid contents and lower total carbohydrates than coated almonds. Three main fatty acids detected in all almond products were palmitic (63.2 g kg^?1), oleic (727.0 g kg^?1) and linoleic (208.0 g kg^?1) acids. The overall acceptance means in roasted almonds, roasted almonds coated with prickle pear syrup and roasted almonds coated with algarrobo pod syrup were 6.83, 6.65 and 6.70, respectively, on a 9‐point hedonic scale. The peroxide and anisidine values increased in all products. The increase was higher in roasted almonds without coating. CONCLUSION: These results indicated that the syrup coatings provided protection against lipid oxidation in almond products. Prickly pear syrup showed better protection against lipid oxidation. Copyright © 2009 Society of Chemical Industry     

Development of a Self‐Assembled Peptide/Methylcellulose‐Based Bioink for 3D Bioprinting

The introduction of 3D bioprinting to fabricate living constructs with tailored architecture has provided a new paradigm for biofabrication, with the potential to overcome several drawbacks of conventional scaffold‐based tissue regeneration strategies. Hydrogel‐based materials are suitable candidates regarding cell biocompatibility but often display poor mechanical properties. Self‐assembling peptides are a promising source of biomaterials to be used as 3D scaffolds based on their similarity to extracellular matrices (structurally and mechanically). In this study, an advanced bioink for biofabrication is presented based on the optimization of a RAD16‐I‐based biomaterial. The strategy followed to build 3D predefined structures by 3D printing is based on an enhancement of bioink viscosity by adding methylcellulose (MC) to a RAD16‐I solution. The resultant constructs display high shape fidelity and stability and embedded human mesenchymal stem cells present high viability after 7 days of culture. Moreover, cells are also able to differentiate to the adipogenic lineage, suggesting the suitability of this novel biomaterial for soft tissue engineering applications.     

Lipolysis,proteolysis and sensory properties of ewe’s raw milk cheese (Idiazabal) made with lipase addition

In this paper, we describe the effect of the addition of pregastric lipase on the composition and sensory properties of Idiazabal cheese. Free fatty acids (FFA), partial glycerides, free amino acids (FAA), gross composition and sensory characteristics were determined at different ripening times in cheeses manufactured with three different amounts of commercial animal lipase or with lipase-containing artisanal lamb rennet paste. The addition of lipase increased the content of total FFA, particularly of short-chain FFA, and that of total partial glycerides in cheeses. Unexpectedly, lipase utilization significantly affected total FAA concentration, which decreased in cheeses elaborated with high lipase amount. In general, Val, Glu and Leu were the major FAA, and their concentrations depended, mainly, on ripening time. Lipase addition had significant influence on the sensory characteristics of the cheeses, increasing scores for most of the flavour and odour attributes of the cheese. Principal component analysis (PCA) was done including dry matter, FFA, FAA, partial glycerides and odour and flavour attributes of the cheeses. It indicated that aroma and flavour parameters of Idiazabal cheese and the content of short-chain FFA and diglycerides were highly correlated to first principal component (PC1), while texture parameters, compositional variables and FAA were correlated to the second principal component (PC2).     

A Human–Robot Cooperative Learning System for Easy Installation of Assistant Robots in New Working Environments

One of the applications of service robots with a greater social impact is the assistance to elderly or disabled people. In these applications, assistant robots must robustly navigate in structured indoor environments such as hospitals, nursing homes or houses, heading from room to room to carry out different nursing or service tasks. Among the main requirements of these robotic aids, one that will determine its future commercial feasibility, is the easy installation of the robot in new working domains without long, tedious or complex configuration steps. This paper describes the navigation system of the assistant robot called SIRA, developed in the Electronics Department of the University of Alcalá, focusing on the learning module, specially designed to make the installation of the robot easier and faster in new environments. To cope with robustness and reliability requirements, the navigation system uses probabilistic reasoning (POMDPs) to globally localize the robot and to direct its goal-oriented actions. The proposed learning module fast learns the Markov model of a new environment by means of an exploration stage that takes advantage of human–robot interfaces (basically speech) and user–robot cooperation to accelerate model acquisition. The proposed learning method, based on a modification of the EM algorithm, is able to robustly explore new environments with a low number of corridor traversals, as shown in some experiments carried out with SIRA.     

Gold glyconanoparticles as new tools in antiadhesive therapy

Gold glyconanoparticles (GNPs) have been prepared as new multivalent tools that mimic glycosphingolipids on the cell surface. GNPs are highly soluble under physiological conditions, stable against enzymatic degradation and nontoxic. Thereby GNPs open up a novel promising multivalent platform for biological applications. It has recently been demonstrated that specific tumor-associated carbohydrate antigens (glycosphingolipids and glycoproteins) are involved in the initial step of tumor spreading. A mouse melanoma model was selected to test glyconanoparticles as possible inhibitors of experimental lung metastasis. A carbohydrate-carbohydrate interaction is proposed as the first recognition step for this process. Glyconanoparticles presenting lactose (lacto-GNPs) have been used successfully to significantly reduce the progression of experimental metastasis. This result shows for the first time a clear biological effect of lacto-GNPs, demonstrating the potential application of this glyconanotechnology in biological processes.     

Cell response to magnetic glyconanoparticles: does the carbohydrate matter?

Magnetic nanoparticles have been used in therapeutic and diagnostic approaches in biomedicine for many years. For these applications, it is very important to investigate the nanoparticle-cell interactions. In this study we report a simple method for the preparation of gold-iron nanoparticles protected and functionalized with biologically relevant saccharides (maltose, lactose, and glucose). The nanoparticles were subsequently tested in vitro with a human fibroblast cell line to determine biocompatibility, and the cell-particle interactions, using fluorescence and scanning electron microscopies. Different cellular responses were obtained for each type of glyconanoparticle, demonstrating that the cells can recognize the saccharides on the nanoparticles.     

Nanoparticles as nonviral gene delivery vectors

Gene therapy, as therapeutic treatment to genetic or acquired diseases, is attracting much interest in the research community, leading to noteworthy developments over the past two decades. Although this field is still dominated by viral vectors, nonviral vectors have recently received an ever increasing attention in order to overcome the safety problems of their viral counterpart. This review presents the biological aspects involved in the gene delivery process and explores the recent developments and achievements of nonviral gene carriers.