Dynamics of the yeast flora in artisanal country style and industrial dry cured sausage (yeast in fermented sausage)

Yeast can act as an adjunct in the sausage-making process as a way to prevent or reduce excessive acidification during aging of products. Two kinds of process were studied: industrial and artisanal country style. Three hundred and fifty three yeast strains were isolated, characterized and identified by biochemical and molecular techniques. Evolution of pH, Aw, weight loss, bacterial growth and proteolytic and lipolytic activity was studied. Final pH in artisanal country style product was higher than in the industrial sausage. There was little difference noted between final weights of products but it was observed a lower yeast count in artisanal country style sausage. No relevant difference was observed in center or surface yeast count in both products. The biochemical assay identified six yeast genera and the molecular test confirmed four different genera, and further analysis showed predominance of the genera Debaryomyces. The relations between this four genera and isolation point (center or surface of sausage) were established. The presence of yeast in the center/surface of ART sausage was more prevalent than in the same places of industrial sausage.     

Investigations on the hp-Cloud Method by solving Timoshenko beam problems

 The hp-Cloud Method is a new and promising approximation technique which, without relying on a mesh, can be used in both finite and boundary element methods. In spite of its great success in solving problems with high accuracy and convergence rates, there are still a number of aspects to be qualitative and quantitatively investigated. Among these are: the sensitivity to the weight functions used in the construction of the Shepard functions, the sensitivity to the class of enrichment functions used in the p-adaptivity, the sensitivity to the cloud overlapping, and the variations of the condition number. This paper describes numerical experiments regarding some of the many choices allowed by the hp-Cloud methodology applied to Timoshenko beam problems. Since the Moving Least Squares Method is used to generate the partition of unity, some choices of weighting functions are studied and the results are compared to each other. In addition, convergence results are presented for successive h-refinements, when the number of clouds is increased, and for increasingly higher order approximation functions characterizing p-refinements. Since the new basis functions are in general not polynomials, an adaptive integration procedure is employed. The efficiency of several types of basis functions is verified. The rates of h and p convergence are determined as functions of other parameters. Also, examples of degradation of the stiffness matrix condition number is displayed and discussed.     

A reduced MIMO Wiener model for recursive identification of the depth of anesthesia

This paper presents a modeling and identification strategy for the depth of anesthesia using the propofol and remifentanil rates as the system inputs, and the bispectral index and state entropy measurements as the systems outputs. The standard model used for this purpose has twenty two patient‐dependent parameters. This high number of parameters, the little input excitation, and the small amount of output data make classical system identification approaches unsuccessful. To overcome these issues, the new model presented in this paper has six parameters, thereby meeting the parsimony principle of system identification. An extended Kalman filter algorithm is also developed and applied to real data. The good fitting results, combined with noise suppression and a recursive update of the model parameters, are promising for the design of the depth of anesthesia controllers to be used in real time platforms. Copyright © 2013 John Wiley & Sons, Ltd.     

Profile of Bioactive Compounds in Avocado Pulp Oil: Influence of the Drying Processes and Extraction Methods

The influence of different procedures of pulp drying and oil extraction methods on the concentrations of α-tocopherol, squalene and several phytosterols in avocado oil was evaluated. Pulp portions of Fortune variety avocados were dried either by lyophilization or under circulating air at 40 or 70 °C. For lyophilization and for each air drying temperature, the oil was obtained either by cold pressing or with Soxhlet extraction using petroleum ether. The dehydrated pulp (73 % of the pulp weight) yielded 25–33 % oil by cold pressing, and 45–57 % oil by Soxhlet extraction. Infrared spectroscopy and gas chromatography with FID and mass spectrometry detection were used to analyze the oils. α-Tocopherol, squalene, cycloartenol acetate, β-sitosterol, campesterol and stigmasterol were present in all the oil samples. In comparison to lyophilization, hot air drying resulted in smaller concentrations of α-tocopherol, squalene and β-sitosterol, and larger relative concentrations of campesterol and cycloartenol acetate. On the other hand, extraction by cold pressing produced a smaller amount of oil, with greater concentrations of α-tocopherol and squalene, and lower contents of campesterol and cycloartenol acetate, than Soxhlet extraction. Thus, the oil yield was maximal with lyophilization and Soxhlet extraction, but lyophilization and cold pressing produced oils which had greater concentrations of antioxidants and other bioactive compounds.     

Synthesis and characterization of a soybean oil‐based macromonomer

An acrylate‐functional soybean oil‐based macromonomer (SoyAA‐1) was synthesized in high yields utilizing sequential amidation and acrylation processes to serve as an internal plasticizer in emulsion polymers. The structure and structure–property relationships of this unique macromonomer were validated with FTIR, NMR, and LC‐MS. The viability of SoyAA‐1 as a comonomer in emulsion polymerization was established via copolymerization with methyl methacrylate (MMA) at varying copolymer weight compositions. The effect of increasing SoyAA‐1 levels and concomitantly higher allylic functionality was measured through film coalescence, minimum film forming temperature, and initial and progressively increasing glass transition temperature(s). The results indicate that synthetic modification of a renewable resource, soybean oil, can yield a valuable monomer that can be copolymerized in high yields via emulsion polymerization to produce practical and mechanically stable latexes for a variety of coatings applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40249.     

Modification of cellulose nanocrystals as reinforcement derivatives for wood coatings

Cellulose nanocrystal (CNC), an emerging renewable nanomaterial, was subjected to carbon chains grafting in order to improve its dispersion and its ability to transfer its rigidity properties into less polar matrixes, especially acrylic wood coatings. Chemical modifications used to this purpose are required to be simple, not affecting the CNC main structure and compatible or synergistic to oligomer reticulation inside the targeted UV-waterborne formulation. Those modifications were carried out using either alkyl quaternary ammonium bromides or acryloyl chloride. These new chemical functionalities, not inducing deep structural changes in modified CNCs, were highlighted through nuclear magnetic resonance, infrared and nitrogen content analyses. CNC derivatives were better dispersed in aqueous acrylic coating as suggested by atomic force microscopy, with a mean surface roughness falling from 9 to 6 nm on the coatings containing unmodified and treated CNCs, respectively. For mechanical evaluations, the coatings including various CNC derivatives were applied on sugar maple wood, a much appreciated material as indoor timber or wooden furniture which requires an efficient surface protection. The abrasion tests indicated that the modified CNCs confer a higher scratch resistance, with an improvement from 24% to 38% for coatings containing CNC derivatives over those with unmodified CNC.     

Effect of surface ligands on the optical properties of aqueous soluble CdTe quantum dots

We investigate systematically the influence of the nature of thiol-type capping ligands on the optical and structural properties of highly luminescent CdTe quantum dots synthesized in aqueous media, comparing mercaptopropionic acid (MPA), thioglycolic acid (TGA), 1-thioglycerol (TGH), and glutathione (GSH). The growth rate, size distribution, and quantum yield strongly depend on the type of surface ligand used. While TGH binds too strongly to the nanocrystal surface inhibiting growth, the use of GSH results in the fastest growth kinetics. TGA and MPA show intermediate growth kinetics, but MPA yields a much lower initial size distribution than TGA. The obtained fluorescence quantum yields range from 38% to 73%. XPS studies unambiguously put into evidence the formation of a CdS shell on the CdTe core due to the thermal decomposition of the capping ligands. This shell is thicker when GSH is used as ligand, as compared with TGA ligands.