Yeasts as sustainable biocontrol agents against ochratoxigenic Aspergillus species and in vitro optimization of ochratoxin A detoxification.

Aims: The aims of this study were to evaluate the potential of Hanseniaspora opuntiae, Meyerozyma caribbica, and Kluyveromyces marxianus for in vitro biocontrol of Aspergillus ochraceus, A. westerdijkiae, and A. carbonarius growth, the ochratoxin A (OTA) effect on yeast growth, and yeast in vitro OTA detoxification ability using an experimental design to predict the combined effects of inoculum size, incubation time, and OTA concentration.

Calibration Transfer of Partial Least Squares Regression Models between Desktop Nuclear Magnetic Resonance Spectrometers.

Low-field proton nuclear magnetic resonance (LF-H NMR) devices based on permanent magnets are a promising analytical tool to be extensively applied to the process analytical chemistry scenario. To enhance its analytical applicability in samples where the spectral resolution is compromised, multivariate regression methods are required. However, building a robust calibration model, such as partial least squares (PLS) regression, is a laborious task because (1) the number of measurements required during the calibration process is large and (2) the procedure must be repeated when the instrument is changed or after a certain period due to the long-term stability of the instrument.

Mathematical modeling of multicomponent NaCl and KCl diffusion process during the salting of pre-cooked champignon mushrooms.

Wet salting is an old preservation method however the NaCl has been frequently associated to high blood pressure issues. The KCl has been used as partial replacement without affecting the acceptability of the final product. In this study, the simultaneous diffusion of NaCl and KCl in champignon mushrooms in static brine and brine under agitation was modeled based on the generalization of Fick's second diffusion law and simulated using the finite element method.

Application of self-organising maps towards segmentation of soybean samples by determination of amino acids concentration.

Soybeans are widely used both for human nutrition and animal feed, since they are an important source of protein, and they also provide components such as phytosterols, isoflavones, and amino acids. In this study, were determined the concentrations of the amino acids lysine, histidine, arginine, asparagine, glutamic acid, glycine, alanine, valine, isoleucine, leucine, tyrosine, phenylalanine present in 14 samples of conventional soybeans and 6 transgenic, cultivated in two cities of the state of Paraná, Londrina and Ponta Grossa. The results were tabulated and presented to a self-organising map for segmentation according planting regions and conventional or transgenic varieties.

Study of levan productivity from Bacillus subtilis Natto by surface response methodology and its antitumor activity against HepG2 cells using metabolomic approach.

Levan productivity of Bacillus subtilis Natto was evaluated in submerged culture varying the pH, temperature and culture time, using factorial design and response surface methodology. The characterization of levan molecular weight was performed by HPSEC and its antitumor activity against HepG2 cells using metabolomic approach was also evaluated. At first, the variables investigated, as well as their interactions, demonstrated significant effect.

Application of self-organising maps towards segmentation of soybean samples by determination of inorganic compounds content.

Background: In this study, 20 samples of soybean, both transgenic and conventional cultivars, which were planted in two different regions, Londrina and Ponta Grossa, both located at Paraná, Brazil, were analysed. In order to verify whether the inorganic compound levels in soybeans varied with the region of planting, K, P, Ca, Mg, S, Zn, Mn, Fe, Cu and B contents were analysed by an artificial neural network self-organising map.

Results: It was observed that with a topology 10 × 10, 8000 epochs, initial learning rate of 0.

Extracellular beta-glucosidase production by the yeast Debaryomyces pseudopolymorphus UCLM-NS7A: optimization using response surface methodology.

beta-Glucosidase production by Debaryomyces pseudopolymorphus UCLM-NS7A using a simple nutrient medium containing cellobiose was evaluated under several biochemical and physiological parameters in submerged fermentation. Enzyme induction was also examined using different carbon and nitrogen sources. Cellobiose and ammonium nitrate were the best C and N sources to enhance beta-glucosidase production.