Antioxidant and antimicrobial potentials of Serbian red wines produced from international Vitis vinifera grape varieties

BACKGROUND: Antioxidant and antimicrobial potentials of Serbian red wines produced from different international Vitis vinifera grape varieties and their correlation with contents of phenolic compounds were studied by spectrophotometric and chromatographic methods. The antioxidant activity of red wines was estimated through their ability to scavenge 2,2′‐diphenyl‐1‐picrylhydrazyl free radical (DPPH^?). The red wines, gallic acid, (+)‐catechin and quercetin were screened in vitro for antimicrobial activity against Gram‐positive and Gram‐negative strains using microdilution and disc diffusion techniques. RESULTS: Excellent correlations between the contents of quercetin‐3‐glucoside (R² = 0.9463) and quercetin (R² = 0.9337) and DPPH^?‐scavenging ability of the red wines were found. Serbian red wines exhibited significant activity against Staphylococcus aureus, Listeria inocua, Micrococcus flavus, Sarcina lutea, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis and Shigella sonnei strains, which was in correlation with their phenolic composition and antioxidant activity. The compounds gallic acid, quercetin and (+)‐catechin showed high activity against B. subtilis, S. aureus, S. lutea and M. flavus Gram‐positive and S. enteritidis and P. aeruginosa Gram‐negative strains. CONCLUSION: The results show that quercetin‐3‐glucoside and quercetin concentrations can be used as markers for the determination of antioxidant and antimicrobial potentials of red wines. Copyright © 2012 Society of Chemical Industry     

Buckwheat (Fagopyrum esculentum Moench) Grain and Fractions: Antioxidant Compounds and Activities

Abstract: Buckwheat (Fagopyrum esculentum Moench) is an alternative crop belonging to the Polygonaceae family. In comparison to antioxidant activity of frequently used cereals, buckwheat has been reported to possess higher antioxidant activity (AOA), mainly due to high rutin content. The objective of this work was to determine the main antioxidant compounds and AOA of buckwheat grain fractions (whole grain, hull, and groat). Buckwheat grain fractions were extracted with ethanol/water (80/20, v/v), followed by determination of total phenolic and flavonoid content. Quantification of phenolic compounds and tocopherols was performed by high‐performance liquid chromatography (HPLC). The AOA was estimated by 2 direct electron spin resonance (ESR) and 4 indirect (spectrophotometric) tests. Significantly higher contents of total phenolics and total flavonoids were found in buckwheat hull than in whole grain and groat. Protocatechuic, syringic, and sinapic acid, rutin, and quercetin were found in all tested fractions, whereas vanilic acid was found in whole grain and hull. The content of total tocopherols in investigated samples ranged from 23.3 mmol/g for hull to 61.8 mmol/g for groat. Hull was superior in scavenging activity on 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH^?), hydroxyl (^?OH), and superoxide anion (O₂^?‐) radicals, reducing activity, AOA by β‐carotene bleaching method, and chelating activity on Fe²⁺ as evidenced by its lower IC₅₀ value. Obtained results can broaden the utilization of buckwheat, especially a share of hull in whole grain flour production. Practical Application: Obtained results suggest possibility to supplement the whole grain buckwheat flour with hull, which leads toward better usage of by‐products in buckwheat production, and enhancement of antioxidant potential of the final product.     

Concentrations and bioconcentration factors of minerals in yellow-cracking bolete (xerocomus subtomentosus) mushroom collected in noteć forest, poland

Abstract: Yellow‐cracking Bolete (Xerocomus subtomentosus) mushrooms and soil were collected from Note? Forest–a large forested enclave in western part of Poland. Mercury was determined by cold vapour atomic absorption spectroscopy and the other elements by inductively coupled plasma atomic emission spectroscopy. K, P, and Mg were particularly abundant, with mean values of 46000, 8400, and 1100 mg/kg dry weight (dw) in caps followed by Na, Rb, Zn, and Ca with mean concentrations of 580, 350, 200, and 170 mg/kg dw, respectively. In descending order, the mean concentrations of Fe, Al, Cu, and Mn were 52, 49, 46, and 14 mg/kg dw, while the mean for the remaining elements was around 1.0 mg/kg dw or less. The elements such as Ca, Cu, Hg, K, Mg, Na, P, Rb, Zn, Ag, Cd, and Ni were accumulated (with bioconcentration factor (BCF) > 1), while Al, Ba, Fe, Mn, Sr, Co, Cr, and Pb were excluded (BCF < 1) in the fruiting bodies. The Pb and Cd content did not exceed the maximum levels set by the EU for cultivated mushrooms. Mercury in a conventional meal (300 g) portion of Yellow‐cracking Bolete was far below the provisionally tolerable weekly intake of 0.004 mg/kg body weight (bw) as reevaluated recently by WHO. Practical Application: The method presented in this study allows one to determine the content of 20 elements (Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr, and Zn) in caps and stipes of Yellow‐cracking Bolete (Xerocomus subtomentosus) mushrooms and soil samples collected from Poland. This study has revealed that the total Cd, Hg, and Pb dose provided to human body due to consumption of Yellow‐cracking Bolete does not pose threat to a consumer's health.     

The effect of muscle, cooking method and final internal temperature on quality parameters of beef roast

The aim of the study was to evaluate the influence of cooking conditions (dry air and steam) and final internal temperature (75, 85, 95°C) on the physico-chemical properties of beef infraspinatus (INF) and semimembranosus (SEM) muscles as well as their tenderness and juiciness. Cooking method and temperature influenced moisture, total collagen content in cooked meat and cooking loss, whereas muscle type affected fat, total collagen content and cooking loss. Warner-Bratzler shear force values were affected by cooking method, which also influenced juiciness of roasts. Temperature affected tenderness and juiciness, whereas muscle type influenced juiciness. The most desirable tenderness had INF heated in steam and dry air to 95°C. Processing SEM in dry air to 85 and 95°C lowered the juiciness of the roasts. There were significant correlations between physico-chemical, sensorial and image attributes, however high accuracy of prediction (r(2)>0.8) was achieved only for SEM muscle.     

Effect of refining processes on antioxidant capacity,total contents of phenolics and carotenoids in palm oils

Antioxidant capacity (AC), total phenolic content (TPC) and total carotenoid content (TCC) in palm oils at various stages of the refining process from two technological modes were determined. The obtained mean FRAP and DPPH values for the methanolic extracts of palm oils from mode 1 (19.5–102.8 μmol TE/100 g and 18.8–103.0 μmol TE/100 g) were lower than for oils from mode 2 (25.6–134.8 μmol TE/100 g and 25.4–135.4 μmol TE/100 g). The total phenolics (4.1–12.4 mg GA/100 g) and carotenoids (0.18–45.8 mg/100 g) in the studied oils were correlated with their antioxidant capacities determined by FRAP and DPPH methods (r = 0.6623–0.9878). During the refining process, for both technological modes resulted in a loss of AC by 80%, TPC by 26–55% and TCC by 99%. The bleaching step caused the highest losses of AC as determined by FRAP 41% and 46%, DPPH by 43% and 48%, while TPC loss was 45% and 23% and loss of carotenoids was 49% and 56%, in mode 1 and mode 2, respectively.     

Mitigation of Sn Whisker Growth by Composite Ni/Sn Plating

Tin (Sn) is a key industrial material in coatings on various components in the electronics industry. However, Sn is prone to the development of filament-like whiskers, which is the leading cause of many types of damage to electronics reported in the last several decades. Due to its properties, a tin-lead (Sn-Pb) alloy coating can mitigate Sn whisker growth. However, the demand for Pb-free surface finishes has rekindled interest in the Sn whisker phenomenon. In order to achieve properties similar to those naturally developed in a Sn-Pb alloy coating, we carried out a study on deposited films with other Sn alloys, such as tin-bismuth (Sn-Bi), tin-zinc (Sn-Zn), and tin-copper (Sn-Cu), electrodeposited onto a brass substrate by utilizing a pulse plating technique. The results indicated that the Sn alloy films modified the columnar grain structure of pure Sn into an equiaxed grain structure and increased the incubation period of Sn whisker growth. The primary conclusions were based on analysis of the topography and microstructural characteristics in each case, as well as the stress distribution in the plated films computed by x-ray diffraction, and the␣amount of Sn whisker growth in each case, over 6 months under various environmental influences.     

The Effect of Micro-Alloying of Sn Plating on Mitigation of Sn Whisker Growth

Tin (Sn) is a key industrial material in coatings on various components in the electronics industry. However, Sn is prone to the development of filament-like whiskers, which is the leading cause of many types of damage to electronics reported in the last several decades. Due to its properties, a tin-lead (Sn-Pb) alloy coating can mitigate Sn whisker growth. However, the demand for Pb-free surface finishes has rekindled interest in the Sn whisker phenomenon. In order to achieve properties similar to those naturally developed in a Sn-Pb alloy coating, we carried out a study on deposited films with other Sn alloys, such as tin-bismuth (Sn-Bi), tin-zinc (Sn-Zn), and tin-copper (Sn-Cu), electrodeposited onto a brass substrate by utilizing a pulse plating technique. The results indicated that the Sn alloy films modified the columnar grain structure of pure Sn into an equiaxed grain structure and increased the incubation period of Sn whisker growth. The primary conclusions were based on analysis of the topography and microstructural characteristics in each case, as well as the stress distribution in the plated films computed by x-ray diffraction, and the?amount of Sn whisker growth in each case, over 6 months under various environmental influences.     

Phages and engineered lysins as an effective tool to combat Gram-negative foodborne pathogens

One of the biggest challenges faced by food producers is ensuring microbiological safety. Despite strict criteria for food products, foodborne diseases are a global problem and pose a real risk to consumers. Therefore, it is necessary to identify new and more effective methods for eliminating pathogens from food and the food processing environment. According to the European Food Safety Authority (EFSA), the most common foodborne diseases are caused by Campylobacter, Salmonella, Yersinia, Escherichia coli, and Listeria. Out of the five listed, four are Gram-negative bacteria. Our review focuses on the use of bacteriophages, which are ubiquitous bacterial viruses, and bacteriophage endolysins to eliminate Gram-negative pathogens. Endolysins cleave specific bonds within the peptidoglycan (PG) of the bacterial cell, causing the cell to burst. Single phages or phage cocktails, which are, in some instances, commercially available products, eliminate pathogenic bacteria in livestock and various food matrices. Endolysins have matured as the most advanced class of antibacterial agents in the clinical sector, but their use in food protection is highly unexplored. Advanced molecular engineering techniques, different formulations, protein encapsulation, and the addition of outer membrane (OM) permeabilization agents enhance the activity of lysins against Gram-negative pathogens. This creates space for groundbreaking research on the use of lysins in the food sector.     

Patient dose measurements in diagnostic radiology procedures in Montenegro

It was the aim of the study presented here to estimate for the first time patient dose levels in conventional diagnostic radiology in Montenegro. Measurements of patient dose in terms of entrance surface air kerma (ESAK) and kerma-area product (KAP) were performed on at least 10 patients for each examination type, in each of five randomly selected health institutions in Montenegro, so that a total of 872 patients for 16 different examination categories were included in the survey (817 patients for 1049 radiographies and 55 fluoroscopy patients). Exposure settings and individual data were recorded for each patient. Mean, median and third quartile values ESAK of patient doses are reported. The estimated mean ESAK values obtained are as follows: 4.7 mGy for pelvis anteroposterior (AP), 4.5 mGy for lumbar spine AP, 7.8 mGy for lumbar spine lateral (LAT), 3.1 mGy for thoracic spine AP and 4.3 mGy for thoracic spine LAT. When compared with the European diagnostic reference values, the mean ESAK for all studied examination types are found to be below the reference levels, except in chest radiography. Mean ESAK values for chest radiography are 0.9 mGy for posteroanterior (PA) projection and 2.0 mGy for LAT. The results exhibit a wide range of variation. For fluoroscopy examinations, the total KAP was measured. The mean KAP value per procedure for barium meal is found to be 22 Gy cm(2), 41 Gy cm(2) for barium enema and 19 Gy cm(2) for intravenous urography. Broad dose ranges for the same types of examinations indicate the necessity of applying practice optimisation in diagnostic radiology and establishment of national diagnostic reference levels.     

Effect of Hydrothermal Treatment of Rapeseed on Antioxidant Capacity of the Pressed Rapeseed Oil

Response surface methodology (RSM) was used to evaluate the quantitative effects of two independent variables, rapeseed moisture content and conditioning temperature, on the antioxidant capacity (AC) and total phenolic (TPC), tocopherol (TTC), and phosphorus contents (PC) in the pressed rapeseed oils. The mean AC results for the crude rapeseed oils ranged from 199.8 to 947.2 μmolTE/100 g. TPC and PC in the crude rapeseed oils correlated significantly (P < 0.01) and positively with AC of oils (R ² = 0.9498 and 0.4396, respectively). The experimental results of AC, TPC, and PC were close to the predicted values calculated from the polynomial response surface model equations (R ² = 0.9801, 0.9747 and 0.9165, respectively). The effect of oil processing temperature on AC and TPC was about 1.5 times greater than the effect of moisture level in rapeseed.