Effect of Gamma Irradiation on Fat Content, Fatty Acids, Antioxidants and Oxidative Stability of Almonds, and Electron Paramagnetic Resonance (EPR) Study of Treated Nuts.

Gamma irradiation has been applied as an efficient and inexpensive method for the sterilization of nuts for years. However, along with the benefits of such treatment, negative effects are possible because of the formation of reactive oxygen species with a toxic effect on important biologically active substances. Because of the scarce and contradictory information in the literature about gamma-irradiated almonds, the aim of our work was the examination of the lipid changes, antioxidant activity, and oxidative stability of almonds treated by 10 and 25 kGy gamma rays, as well as changes in intensity of the EPR spectra as an indicator for the stability of radiation-induced free radicals. The results revealed no significant differences in the EPR spectra of almonds treated at 10 and 25 kGy doses, neither in their intensity nor in kinetic behaviour. The EPR signals decayed exponentially over 250 days, with a decreasing of central line by 90%, with satellite lines by about 73%. No significant changes in the fat content, fatty acids composition, and acid value of irradiated almonds were observed. However, the amount of (alpha)tocopherols decreased from 292 to 175 mg/kg, whereas the conjugated dienes and trienes increased, K232 from 1.3 to 3 and K268 from 0.04 to 0.15, respectively, with the increasing of irradiation dose. The same was observed for total polyphenols in defatted almonds (1374 to 1520 mg/100 g), where in vitro antioxidant activity determined by ORAC and HORAC methods increased from 100 to 156 µmol TE/g and from 61 to 86 µmol GAE/g, respectively. The oxidative stability of oil decreased from 6 to 4 h at 120 °C and from 24.6 to 18.6 h at 100 °C (measured by Rancimat equipment). The kinetic parameters characterizing the oxidative stability of oil from 10 kGy irradiated almonds were studied before and after addition of different concentrations of ascorbyl palmitate as a synergist of tocopherols. Its effectiveness was concentration-dependent, and 0.75 mM ensured the same induction period as that of non-irradiated nut oil. Further enrichment with alpha-tocopherol in equimolar ratio with palmitate did not improve the oil stability. In conclusion, gamma irradiation is an appropriate method for the treatment of almonds without significant changes in fat content and fatty acids composition. The decreasing of oxidative stability after higher irradiation could be prevented by the addition of ascorbyl palmitate.

Evaluation of gamma irradiation effects on antioxidant capacity of propolis.

The irradiation effects on antioxidant potential and on content of phenolic compounds of propolis ethanoic extracts were studied. It was found out that gamma treatment of samples with 2 and 10 kGy had a weak decreasing effect on the total phenolic content (TPC), while no change was observed in the propolis irradiated with 5 kGy. The antiradical activity of extracts was assessed by the DPPH free radical scavenging activity evaluated by Electron Paramagnetic Resonance (EPR) spectroscopy. The EPR results were in agreement with TPC. Some main phenolic compounds of the studied non-irradiated and irradiated samples were identified and compared by ultra-high performance liquid chromatography (UHPLC).

Health-Related Quality of Life following Surgery for Native and Prosthetic Valve Infective Endocarditis.

OBJECTIVES: The objective of this study was to compare the long-term outcomes and health-related quality of life (HRQOL) of patients following surgery for infective native valve endocarditis (NVE) and prosthetic valve endocarditis (PVE). METHODS: We retrospectively identified 633 consecutive patients who had undergone surgery for infective endocarditis at our center between January 2005 and October 2018. The patients were interviewed, and the SF-36 survey was used to assess the HRQOL of survivors. Propensity score matching (2:1) was performed with data from a German reference population. Multivariable analysis incorporated binary logistic regression using a forward stepwise (conditional) model. RESULTS: The median age of the cohort was 67 (55-74) years, and 75.6% were male. Operative mortality was 13.7% in the NVE group and 21.6% in the PVE group (p = 0.010). The overall survival at 1 year was 88.0% and was comparable between the groups. The physical health summary scores were 49 (40-55) for the NVE patients and 45 (37-52) for the PVE patients (p = 0.043). The median mental health summary scores were 52 (35-57) and 49 (41-56), respectively (p = 0.961). On comparison of the HRQOL to the reference population, the physical health summary scores were comparable. However, significant differences were observed with regard to the mental health summary scores (p = 0.005). CONCLUSIONS: Our study shows that there are significant differences in the various domains of HRQOL, not only between NVE and PVE patients, but also in comparison to healthy individuals. In addition to preoperative health status, it is important to consider the patient's expectations regarding surgery. Further prospective studies are required.

EPR study of free radicals in bread.

The features of the recorded EPR spectra of paramagnetic species formed in bread and rusk are reported. The appearance of free radicals in them is only connected with their thermal treatment since the starting materials (flour and grains) exhibit very weak EPR signal. The obtained EPR spectra are complex and indicate that: (i) the relative number of paramagnetic species depends on the temperature and treating time of the raw product; (ii) the g-values are strongly temperature dependent with a tendency to coincide at t > or = 220 degrees C. Because of the relatively low (150-220 degrees C) temperature of thermal treatment, the studied free radicals can be assumed to appear in the course of the browning (Maillard) reaction and not to the carbonization of the material.