35 research outputs found

    Microwave-based technique for fast and reliable extraction of organic contaminants from food, with a special focus on hydrocarbon contaminants

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    Due to food complexity and the low amount at which contaminants are usually present in food, their analytical determination can be particularly challenging. Conventional sample preparation methods making use of large solvent volumes and involving intensive sample manipulation can lead to sample contamination or losses of analytes. To overcome the disadvantages of conventional sample preparation, many researchers put their efforts toward the development of rapid and environmental-friendly methods, minimizing solvent consumption. In this context, microwave-assisted-extraction (MAE) has obtained, over the last years, increasing attention from analytical chemists and it has been successfully utilized for the extraction of various contaminants from different foods. In the first part of this review, an updated overview of the microwave-based extraction technique used for rapid and efficient extraction of organic contaminants from food is given. The principle of the technique, a description of available instrumentation, optimization of parameters affecting the extraction yield, as well as integrated techniques for further purification/enrichment prior to the analytical determination, are illustrated. In the second part of the review, the latest applications concerning the use of microwave energy for the determination of hydrocarbon contaminants-namely polycyclic aromatic hydrocarbons (PAHs) and mineral oil hydrocarbons (MOH)-are reported and critically overviewed and future trends are delineated

    Occurrence of n-Alkanes in vegetable oils and their analytical determination

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    Vegetable oils contain endogenous linear hydrocarbons, namely n-alkanes, ranging from n-C21 to n-C35 with odd chain lengths prevalent. Different vegetable oils, as well as oils of the same type, but of different variety and provenience, show typical n-alkane patterns, which could be used as a fingerprint to characterize them. In the first part of this review, data on the occurrence of n-alkanes in different vegetable oils (total and predominant n-alkanes) are given, with a focus on obtaining information regarding variety and geographical origin. The second part aims to provide the state of the art on available analytical methods for their determination. In particular, a detailed description of the sample preparation protocols and analytical determination is reported, pointing out the main drawbacks of traditional sample preparation and possible solutions to implement the analysis with the aim to shift toward rapid and solvent-sparing methods

    DIFFERENT APPROACHES IN ANALYZING CHYMOSIN PURITY

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    Chymosin is a specific proteolytic enzyme found in rennet, and is the key enzyme in cheese production classified in the aspartic endopeptidases (EC 3.4.23.4). The aim of this study was to determine the purity of different commercially available chymosins and its equivalents using electrophoretic and chromatographic techniques. Chymosins produced by the company Chr. Hansen, CHY-MAX 200 and CHY-MAX Plus, CHY-MAX PowderExtra NB, as well as Maxiren 1800 Granulate from the company DSM, Sirnik from SZR – Travnik, Kraljevo and Planika from Mikroprocessing, Bileca were used as materials for this study. The purity level of the commercially available enzymes was analyzed using electrophoretic (sodium dodecyl sulfate polyacrylamide gel electrophoresis or SDS-PAGE) and chromatographic (Rapid Resolution Liquid Chromatography or RRLC) techniques. Results showed no presence of undeclared protein fractions due to inappropriate purification process in the samples except for CHY-MAX М 200 which had two protein fractions, most likely as a result of a polymorphism. All the CHY-MAX and Maxiren samples have chymosin as the active component (36 kDa), except for Planika and Sirnik which have a natural protease from R. miehei. Chromatographic analysis showed that beside the active component (chymosin), the preservative sodium benzoate was present in varying concentrations in all but CHY-MAX PowderExtra NB

    Decision Agriculture

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    In this chapter, the latest developments in the field of decision agriculture are discussed. The practice of management zones in digital agriculture is described for efficient and smart faming. Accordingly, the methodology for delineating management zones is presented. Modeling of decision support systems is explained along with discussion of the issues and challenges in this area. Moreover, the precision agriculture technology is also considered. Moreover, the chapter surveys the state of the decision agriculture technologies in the countries such as Bulgaria, Denmark, France, Israel, Malaysia, Pakistan, United Kingdom, Ukraine, and Sweden. Finally, different field factors such as GPS accuracy and crop growth are also analyzed

    Sex- and age-related differences in the management and outcomes of chronic heart failure: an analysis of patients from the ESC HFA EORP Heart Failure Long-Term Registry

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    Aims: This study aimed to assess age- and sex-related differences in management and 1-year risk for all-cause mortality and hospitalization in chronic heart failure (HF) patients. Methods and results: Of 16 354 patients included in the European Society of Cardiology Heart Failure Long-Term Registry, 9428 chronic HF patients were analysed [median age: 66 years; 28.5% women; mean left ventricular ejection fraction (LVEF) 37%]. Rates of use of guideline-directed medical therapy (GDMT) were high (angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, beta-blockers and mineralocorticoid receptor antagonists: 85.7%, 88.7% and 58.8%, respectively). Crude GDMT utilization rates were lower in women than in men (all differences: P\ua0 64 0.001), and GDMT use became lower with ageing in both sexes, at baseline and at 1-year follow-up. Sex was not an independent predictor of GDMT prescription; however, age >75 years was a significant predictor of GDMT underutilization. Rates of all-cause mortality were lower in women than in men (7.1% vs. 8.7%; P\ua0=\ua00.015), as were rates of all-cause hospitalization (21.9% vs. 27.3%; P\ua075 years. Conclusions: There was a decline in GDMT use with advanced age in both sexes. Sex was not an independent predictor of GDMT or adverse outcomes. However, age >75 years independently predicted lower GDMT use and higher all-cause mortality in patients with LVEF 6445%

    Influence of starter culture, temperature and processing technology on the quality of Macedonian white brined cheese

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    The effect of the starter culture, temperature of curdling and processing technology on the composition, cheese yield and process optimization of Macedonian White cheese (MWC) was studied during 60 days of ripening in brine. Three treatments of cheese were made using current technological process and yogurt as starter-culture gained along processing of previous day (MWCK), freeze dried culture of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus 3:1; F-DVS YF-3331 Yo-Flex version: 2 PI-EU-EN (MWCB1), and (MWCB2) with same starter culture as previous but whith 5 minute earlier processing of curd and temperature of curdling at 39°C. As ripening progressed, titratable acidity (°SH), salt and protein contents of the (MWCB2) treatment continuously increased, whereas their fat-in-dry-matter and lactose contents decreased. In same production conditions depending on the used temperature. Way of processing and starter cultures the cheese from (MWCB2) treatment was with highest acidity of 66.63 + 2.73oSH until the end of ripening of the cheese. Moisture of cheeses remained stable during ripening. The pH of cheese at the 1 day of ripening, which decreased by increasing the temperature of curdling (5.03, 5.11 and 5.00 for MWCK, MWCB1 and MWCB2, respectively), significantly (P < 0.05) affected most of the chemical characteristics of cheese. The content of salt at the end of storage at (B1) and (B2) variant is 5.23 + 0.31 and 5.52 + 0.31 respectively. Higher temperature of curdling decreased moisture and pH, whereas cheese protein content increased. The consumption of milk for production of a 1 kilogram of cheese ranged from 7.8 to 8.3 liters of milk. It was concluded that starter cultures have positively influenced and improved the quality of white cheese

    Application of gas chromatography for quality and authenticity assessment of olive oil

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    The investigation of fraud plays a key role in the authentication of genuine olive oil products, and despite the fact that the olive oil sector is strongly regulated, fats and oils, including olive oils, are ranked in the top positions of the 2016 EU Food Fraud report on non-compliances per product category. Several official analytical methods for the assessment of the quality and purity of olive oil are currently available. However, the process of proposing new methods is constantly in progress with the aim to protect consumers by preventing both traditional and emerging frauds. In view of this, the present chapter will discuss some selected new and/or alternative methods based on the determination of squalene, endogenous n-alkanes, waxes, as well as free and esterified sterols that have the potential to detect illegal blends of olive oil and other vegetable oils

    Spearcon compression levels influence the gap in comprehension between untrained and trained listeners

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    Auditory alarms in hospitals are ambiguous and do not provide enough information to support doctors and nurses’ awareness of patient events. A potential alternative is the use of short segments of\ua0time-compressed speech, or\ua0spearcons. However, sometimes it might be desirable for patients to understand spearcons and sometimes not. We used reverse hierarchy theory to hypothesize that there will be a degree of compression where spearcons are intelligible for trained listeners but not for untrained listeners. In Experiment 1, spearcons were compressed to either 20% or 25% of their original duration. Their intelligibility was very high for trained participants, but also quite high for untrained participants. In Experiment 2 each word within each spearcon was compressed to a different degree based on the results of Experiment 1. This technique was effective in creating the desired difference in spearcon intelligibility between trained and untrained listeners. An implication of these results is that manipulating the degree of compression of spearcons “by word” can increase the effect of training so that untrained listeners reliably do not understand the content of the spearcons

    Mineral oil contamination in basil pesto from the Italian market: Ingredient contribution and market survey

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    Mineral oil hydrocarbons (MOH) are complex mixtures of saturated hydrocarbons (MOSH) which bioaccumulate in human tissues, and aromatic hydrocarbons (MOAH) which include genotoxic and carcinogenic substances. This work aimed to investigate these emerging food contaminants in basil pesto from the Italian market, and ingredient contribution to the final product contamination. Twelve market samples and 4 additional samples (and related ingredients) produced in a pilot plant, were analyzed by on-line high-performance liquid chromatography (HPLC)- gas chromatography (GC), preceded by matrix-tailored sample preparation. Method performance was good with recoveries from 94% to 109%, residual standard deviations (RSD) less than 10%, and a limit of quantitation (LOQ) of 0.5 mg/kg (for total MOAH). Vegetable oils, followed by cashews, which showed a similar contamination profile to foods transported in jute bags, were the major contributors to contamination, while cheese and basil contribution was negligible. Sunflower oil alone accounted for more than 80–85% of the total contamination. Samples from the Italian market had an average of 5.6 and 0.6 mg/kg of MOSH and MOAH, respectively, and a contamination profile that confirmed that the main contributors to total contamination were sunflower oil and cashews. Mitigation actions should be directed toward careful control of these two ingredients
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