A study of the characterization of the phenotypic patterns of Staphylococcus aureus strains isolated from bovine subclinical mastitis in Israeli dairy herds and their correlation with the severity of the disease was undertaken. A total of 400 chronically S. aureus-infected Israeli-Holstein cows, from 15 dairy herds were included in this study. Based on the results of the biochemical reactions, of the anti-biogram and phage typing, one major type of S. aureus was determined in each herd, its prevalence being between 54 and 100% of the total isolates from that same herd. The majority of the isolates were found to be non-haemolytic (62.7%). The most common phage type was 3/A,3/C,55,71, which was predominant in five herds. In two herds none of the isolates (24) were typable by this set of phages. All isolates were susceptible to methicillin, erythromycin, cephalotin, norfloxacin, trimethoprin-sulphamethoxazole and novobiocin. Most isolates were resistant to penicillin (96.6%) and 52% to oxytetracyclin. Differences in protein patterns between 50 and 36 kDa were found by one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis. No correlation between any combination of the phenotypic characteristics was found when correlation was done with milk yield and somatic cell count, corresponding to the 6 months before sampling. Otherwise, a positive correlation was found between type of haemolysis and the N-acetyl-beta-glucosaminidase (NAGase) values. In milk from quarters infected with the-non-haemolytic strains, the level of NAGase was significantly lower (P < 0.05) than that from quarters infected with the haemolytic strains (69.7 and 105.9, respectively). However, the level of NAGase activity in the milk of the quarters infected with the non-haemolytic strains was significantly higher (P < 0.05) when compared to the milk of quarters infected with coagulase-negative staphylococci (43.5).

Foaming of mashes during distillation is a common problem encountered in spirit drink production. It has a negative impact on the purity of the final product. This research article presents the key aspects of foam accumulation in rye mashes during distillation. Foam accumulation was influenced by substrate characteristics and process parameters. The experiments showed that pentosan levels and thermal energy input were the crucial parameters for foam accumulation in rye mashes. Foam accumulation was significantly enhanced by higher pentosan levels, due to the higher viscosity imparted by pentosan. Hence, degradation of pentosans prior to distillation presents a way to reduce foam accumulation. In terms of thermal energy input, foam accumulation was significantly lower when the thermal energy input was reduced from 400 to 200 W/L. Substantial foaming only occurred in a narrow temperature range of 89.5 to 98.2 C. The results allowed for the first time to make recommendations to prevent problematic foam accumulation during distillation of rye mashes.

Fruit spirit distillations processes are based on physical principles of heat and mass transfer. These principles are decisive for the separation of desired and undesired aroma compounds, which affect the quality of the distilled product. It is mandatory to control heat and mass transfer parameters to be able to perform fruit spirit distillation processes in a reproducible manner and to achieve equal products with similar volatile compound compositions repeatedly. Up to now, only limited information is available on the magnitude of reproducibility errors since fruit spirit distillation columns are typically not equipped with a suitable control or monitoring technique. We upgraded a batch distillation column with digitized instrumentation and a control technique to be able to control crucial parameters such as thermal energy inputs and reflux rates. This study aimed to identify whether control over two distillation parameters has the potential to enable us to perform distillation processes repeatedly. This study analyzed the magnitude of reproducibility errors for (i) six monitored distillation process parameters and (ii) 13 quantified volatile compounds in the product between duplicated distillation runs performed with equal setups. A total of eight different distillations were performed in duplicate (n = 16), while the six distillation parameters were monitored and logged every ten seconds. The produced distillates were equally subsampled into 20 fractions and each fraction analyzed for 13 volatile compound concentrations. Based on a dataset of 28,600 monitored duplicate distillation process data points, this study showed that process parameters can indeed be replicated with a median relative standard deviation (RSD) of <0.1% to 7% when two crucial process parameters are controlled. The comparison of 1540 volatile compound concentrations in the product fractions showed a reproducibility error with an average median RSD of 9 ± 8%. This illustrated that by gaining control over thermal energy input and reflux rates, the reproducibility of fruit spirit distillation processes and their associated products can largely be met. It is advisable to equip distillation columns with a suitable control technique to be able to reproduce the performance of fruit spirit distillations.

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There is a large economic interest to characterize heads, hearts and tails fractions during fruit spirit distillation by simple, fast, low-volume and low-cost analytical methods. This study evaluated the potential of ultraviolet (UV)-visible-infrared spectroscopy (230–1000 nm) to characterize and differentiate these distillate fractions. Heads, hearts and tails fractions of 10 different fruit spirits were separated by sensory evaluation and investigated by absorbance spectroscopy. Principal component analysis indicated that UV spectroscopy at a wavelength range from 230 to 310 nm had the highest potential to differentiate all three distillate fractions. While all tails fractions showed significantly different UV spectra, a clear differentiation between heads and hearts fractions was limited. However, an additional UV spectroscopy of 100 mL subfractions sampled during the shift from heads to hearts in three additional distillations did reveal significant differences. The calculated integrals of the according best-fit trendline functions of the spectra indicated a trend towards reduced area-under-the-curve and zero-point values during the shift. This could be a new lead to implement an analytical method for in-line process control during fruit spirit production.