Inactivation of Staphylococcus aureus and native microflora in human milk by high pressure processing

The storage of unpreserved food, including breast milk, is associated with the growth of microorganisms, including pathogenic bacteria. It is therefore necessary to use suitable processes to eliminate pathogenic microorganisms and reduce the total microbial count in order to ensure product safety for consumers. In the present study, samples of milk obtained from volunteers donating to the human milk bank were artificially contaminated with Staphylococcus aureus ATCC 6538. This bacteria was the model microorganism of choice, being relatively resistant to high pressure as well as posing the most serious risk to infant health. The results obtained show that high pressure processing can reduce the count of S. aureus by about 5?log units at 4°C and about 8?log units at 50°C, and totally eliminate Enterobacteriaceae after 5?min of treatment, and result in a total microbial count reduction after 10?min treatment at 500?MPa at 20°C and 50°C. This suggests the possibility of this technology being applied to ensure the adequate safety and quality of human breast milk in human milk banks.     

Dynamics of chemical wave segments with free ends

A quite simple but useful approach is performed for the analysis of chemical wave segments with free ends. By integrating a reaction–diffusion system we can obtain an analytical expression to understand the dynamics of the wave segments. This integration can yield qualitative information regarding wave development under an external forcing having feedback or noise effects. We conclude that this wave development is influenced not only by medium excitability but also by wave size.     

Kinetics of Atmospheric Freeze-drying of Apple

We present investigations of the effect of Atmospheric Freeze-Drying kinetics on the quality (dehydration rate, shrinkage, color, and antioxidant properties) of apple cubes. The experimental data are compared with the result of convective and vacuum freeze-drying processes, and suitable operating parameters are determined. The experiments were carried out in an Internet controlled, fully automated heat-pump assisted drying system.     

Inactivation of extremely halophilic hide-damaging bacteria via low-level direct electric current

The presence of proteolytic and lipolytic extremely halophilic bacteria on brine-cured hides reduces the value of the hide as a raw material for leather manufacturing. Every brine curing raceway that produces hide contains a significant number of extremely halophilic bacteria that contaminate almost every hide. The usual brine raceway treatments used to control bacteria during curing do not control halophilic bacteria. The antibacterial effects of passing 0.5-A low level, direct electric current for 30 min on different species of protease, lipase, both protease and lipase producing extremely halophilic bacteria, as well as a mixed population of extremely halophilic bacteria, were examined in liquid media containing organic substances and 25% NaCl. Although the antibacterial effects varied with different extremely halophilic bacterial species, the application of current demonstrated an antibacterial effect within 20 min of treatment of all species tested. A mixed culture of extremely halophilic bacteria was killed within 10 min. It has been demonstrated that treatment time as short as 5 min is sufficient for the total inactivation of protease producing extremely halophilic bacteria of 10⁷ CFU/mL while lipase or lipase and protease producing extremely halophilic bacteria were inactivated within 20 min. It was also found that the temperature and pH of the test medium increased during treatment. The maximum temperature rise was 9 °C, and the pH increased by 4.     

The influence of selected metals and halogens on the electronic system of benzoic acid

The influence of halogens and metals on the electronic system of the aromatic ring in lithium, sodium and potassium complexes with p-halogenobenzoic acids has been investigated by means of ¹³C and ¹H NMR, IR and Raman spectroscopy and semi-empirical calculations. It has been shown that ionic potentials and electronegativities of halogens and metals are the main factors responsible for perturbations of the electronic charge distribution in the ring.     

Solid-state structures of 2-(4-hydroxyphenyl)-substituted phenalene-1,3-dione and indan-1,3-dione

The structure of 2-(4-hydroxyphenyl)-substituted indan-1,3-dione and phenalene-1,3-dione is investigated using a combination of solid-state NMR, single crystal X-ray analyses and quantum chemical calculations. It is shown that 2-(4-hydroxyphenyl)-1,3-indandione exists as a diketo tautomer while 2-(4-hydroxyphenyl)-1,3-phenalenedione exists in the enol form.     

Measurement of the production cross-section of positive pions in p–Al collisions at 12.9 GeV/c

A precision measurement of the double-differential production cross-section, $d^2{\sigma }^{{\pi }^{+}}/dpd\Omega$, for pions of positive charge, performed in the HARP experiment is presented. The incident particles are protons of $12.9\text{ GeV}/c$ momentum impinging on an aluminium target of 5% nuclear interaction length. The measurement of this cross-section has a direct application to the calculation of the neutrino flux of the K2K experiment. After cuts, 210 000 secondary tracks reconstructed in the forward spectrometer were used in this analysis. The results are given for secondaries within a momentum range from 0.75 to 6.5 GeV/c, and within an angular range from 30 mrad to 210 mrad. The absolute normalization was performed using prescaled beam triggers counting protons on target. The overall scale of the cross-section is known to better than 6%, while the average point-to-point error is 8.2%.     

AROMATICITY OF SOME METAL BENZOATES——EFFECT OF METAL SALTS ON THE AROMATIC SYSTEM OF BENZOIC ACID USING IR, RAMAN AND UV SPECTROSCOPIC METHODS

In this paper,the aromaicity of some metal benzoates has been studied us-ing IR,Raman and UV spectroscopic methods.The bond frequencies in IR andRaman spectra of Hg(Ⅰ),Mg and K benzoates are summarised in table 1.Theeffects of Cr(Ⅲ),Fe(Ⅲ),Cu(Ⅱ),etc.on the aromatic system of benzoic acidwere compared.It is found that Cr(Ⅲ)iron(Ⅲ),Ianthanides and Al can stabi-lize this system.     

The effect of zeolites on copper uptake by plants growing in contaminated soils

Three-year pot experiments were carried out in a greenhouse with the aim of reducing the copper content in the 2nd link of the soil-plant-animal (man) trophic chain. For this purpose, synthetic zeolites of the 3A, 4A, 5A and 13X type were introduced into copper contaminated soils at levels of 1, 2 and 3% by weight in relation to the soil mass. Mono- and dicotyledonous plants were cultivated in mixtures of soils with the zeolites. The copper content in lettuce grown in the contaminated soil decreased in the presence of zeolites by 29–77%, in grass by 41–78%, in oats by 45–64% and in beets by 21–41%, as compared to the control.