Influence of yeast on the yield of fermentation and volatile profile of ‘Węgierka Zwykła’ plum distillates

The character of plum brandies depends on a unique aroma profile of the plum and the microbiota present on the surface of the fruits, as well as yeast used for fermentation. In this study, an evaluation of the effect of microorganisms applied for the fermentation of W?gierka Zwyk?a var. plum mashes and processing temperature (18 °C, 30 °C) on its efficiency and volatile profile, as well as taste and flavour of distillates obtained was performed. An estimation of the odour activity values (OAVs) of the volatile compounds was also conducted. Regardless of whether the fermentation was carried out using Saccharomyces bayanus wine yeast or by native microflora present on plums as well as raisins, the efficiency of this process was high and ranged between 91.7 and 96.7% of the theoretical efficiency. Especially rich in esters (among others ethyl acetate and isoamyl acetate) was the distillate derived after fermentation with the microflora of plums and raisins, at 18 °C. An evaluation of the individual aromatic effect of chemical compounds present in tested distillates, in terms of their OAVs, revealed that the highest OAVs were reached with isovaleraldehyde. Other compounds that showed aroma values >1 and possibly had an effect on the overall aroma of tested plum distillates were the following: hexanal, benzaldehyde, ethyl acetate, isoamyl acetate, ethyl benzoate, ethyl hexanoate, 1‐propanol, 2‐methyl‐1‐butanol, 3‐methyl‐1‐butanol and 1‐hexanol. The performed sensory ranking showed that the best rated distillate was the one obtained after fermentation with the indigenous microflora of plums and raisins, at 18 °C. Copyright © 2016 The Institute of Brewing & Distilling     

Electrophoretic Deposition,Microstructure, and Corrosion Resistance of Porous Sol–Gel Glass/Polyetheretherketone Coatings on the Ti-13Nb-13Zr Alloy

Metallurgical and Materials Transactions A - In this study, microporous composite sol–gel glass/polyetheretherketone (SGG/PEEK) coatings were produced on the Ti-13Nb-13Zr titanium alloy by...     

Anticorrosive effectiveness of coatings with reduced content of Zn pigments in comparison with zinc-rich primers

ABSTRACT

Typically, an anticorrosive coating system for long-term protection consists of a primer, one or several intermediate coats, and a topcoat. In such systems, zinc-rich primers are often used as they ensure good adhesion to the substrate and protect it from corrosion. Such coatings are very highly pigmented, which sometimes leads to losses in cohesive strength and deterioration of mechanical properties. Furthermore, Zn is known to be harmful to the environment. In this work we present Zn primers with reduced Zn content and better protective properties than traditional zinc-rich primers. The formulations of different Zn pigments in the epoxy matrix were developed with the concentration of zinc particles reduced to about 50% in the dry coating. To evaluate the distribution of pigments scanning electron microscopy has been employed. The anticorrosive properties were tested using the salt spray test and electrochemical impedance spectroscopy. The mechanical properties of the coatings were also tested.