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41.
Fast headspace-enantioselective GC-mass spectrometric-multivariate statistical method for routine authentication of flavoured fruit foods 总被引:1,自引:0,他引:1
Cecilia CaglieroCarlo Bicchi Chiara CorderoPatrizia Rubiolo Barbara SgorbiniErica Liberto 《Food chemistry》2012,132(2):1071-1079
This study describes a rapid total analysis system (TAS) to detect the authenticity of fruit-flavoured foods and beverages by on-line combining headspace solid phase microextraction (HS-SPME) with enantioselective GC-MS (Es-GC-MS) and statistical multivariate methods (PCA, HCA). Peach, coconut, apricot, raspberry, as fruits mainly characterised by γ- and δ-lactones as chiral markers, strawberry (α-ionone, linalool, nerolidol, ethyl 2-methylbutyrate, 2-methylbutyric acid and γ-lactones) and melon (ethyl 2-methylbutyrate and 2-methylbutanol) were investigated. The system was developed by (a) optimising non-equilibrium HS-SPME sample preparation, (b) speeding-up ES-GC using cyclodextrin derivatives as chiral selectors with conventional and narrow-bore columns and (c) elaborating data by multivariate methods. The resulting TAS affords a reduction of the time needed for the whole analytical process from about 150 min to 20-50 min (67-87% of the current routine method) depending on matrix, sampling and analysis conditions and Es-GC columns. 相似文献
42.
Analía V. Gómez Cristina Ferrero Cecilia Puppo Carmen C. Tadini Analía G. Abraham 《International Journal of Food Science & Technology》2014,49(10):2315-2322
The objectives of this research were to study the effect of the addition of lyophilised kefir milk to premixes for household production of bread and evaluate the quality attributes of them. Four lyophilised samples were obtained from the followings: skim milk, acidified skim milk, fermented skim milk and neutralised fermented skim milk. Breads were prepared with commercial wheat flour, lyophilised milk samples and yeast through a straight dough process. Quality was assessed through loaf volume, crumb porosity and moisture, crumb texture and crust colour. Changes in texture and starch recrystallisation by X‐ray diffractometry were determined after 1 and 3 days of storage at room temperature. Breads with acidified milks showed the highest specific volumes and crumbs with the best texture properties. Crystallinity in bread with fermented milks was higher than for skim milk sample. This would indicate that there would be a certain effect of the type of milk processing on the promotion of starch retrogradation. 相似文献
43.
Cecilia Poletti Tomasz Wójcik Christof Sommitsch 《Metallurgical and Materials Transactions A》2013,44(3):1577-1586
Hot deformation of AA6082 aluminum alloy was studied by compression tests carried out between 573 K and 823 K (300 °C and 550 °C) under a wide range of strain rates. Light optical and scanning electron microscopy were used to study the as-received microstructure, which consisted of elongated, partially recrystallized grains containing fine Mg2Si and AlFeMnSi particles. The hot-deformed material showed the effects of dynamic recovery, i.e., small low angle grain boundary formation and dislocation pinning by fine particles. The flow data were used to calculate the constitutive equations, obtaining high values of n exponent. This behavior was attributed to the interaction of particles with dislocations during hot deformation. Threshold stresses were introduced to adjust the constitutive equation to a n exponent value of 5 at high stresses and a value of 3 in the low stresses range, which was related to dislocations’ climbing and sliding and thus to dynamic recovery. The threshold values were related to the detachment stresses in close connection with the precipitation state which was a function of the deformation temperature. 相似文献
44.
Tania Martellini Chiara Berlangieri Luigi Dei Emiliano Carretti Saul Santini Angelica Barone Alessandra Cincinelli 《Indoor air》2020,30(5):900-913
Indoor Air Quality monitoring in cultural institutions is of particular concern to protect these places and the cultural heritage content. An indoor monitoring campaign was performed in three museums in Florence (Italy) to determine the occurrence and levels of volatile organic compounds (VOCs). VOCs of interest included BTEX (benzene, toluene, ethylbenzene, xylenes), terpenes, aldehydes, organic acids, and cyclic volatile methyl siloxanes (cVMS). The most abundant VOCs in all samples analyzed were BTEX, which were strictly related to the traffic source, followed by siloxanes and terpenes. Among BTEX, toluene was always the most abundant followed by xylenes, ethylbenzene, and benzene. cVMS in exhibition rooms with the presence of visitors showed higher values compared to samples collected when the museums were closed. Terpenes showed not only the influence of vegetation-biogenic sources surrounding a museum but could also be related to the wood used for the construction of showcases and furniture and the use of cleaning products. Data obtained also showed the presence of organic acids and aldehydes whose source can be traced back to exhibits themselves and wood-based furniture. Assessing the levels of organic acids in museums is important because, over time, it can cause deterioration of the artifacts. 相似文献
45.
Chester J. Lau Max Loebel Roson Keifer M. Klimchuk Tania Gautam Boyang Zhao Ran Zhao 《Indoor air》2021,31(3):769-782
Household humidification is widely practiced to combat dry indoor air. While the benefits of household humidification are widely perceived, its implications to the indoor air have not been critically appraised. In particular, ultrasonic humidifiers are known to generate fine particulate matter (PM). In this study, we first conducted laboratory experiments to investigate the size, quantity, and chemical composition of PM generated by an ultrasonic humidifier. The mass of PM generated showed a correlation with the total alkalinity of charge water, suggesting that CaCO3 is likely making a major contribution to PM. Ion chromatography analysis revealed a large amount of SO42− in PM, representing a previously unrecognized indoor source. Preliminary results of organic compounds being present in humidifier PM are also presented. A whole-house experiment was further conducted at an actual residential house, with five low-cost sensors (AirBeam) monitoring PM in real time. Operation of a single ultrasonic humidifier resulted in PM2.5 concentrations up to hundreds of μg m−3, and its influence extended across the entire household. The transport and loss of PM2.5 depended on the rate of air circulation and ventilation. This study emphasizes the need to further investigate the impact of humidifier operation, both on human health and on the indoor atmospheric chemistry, for example, partitioning of acidic and basic compounds. 相似文献
46.
Metal‐Organic Framework Surface Functionalization: GraftFast Surface Engineering to Improve MOF Nanoparticles Furtiveness (Small 40/2018)
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47.
Inés González‐Hidalgo Sancho Bañón José María Ros 《International Journal of Food Science & Technology》2012,47(4):674-681
The main by‐product from the table olive canning industry is the stone with some residual olive flesh. The purpose of this study was to evaluate the composition – phenolic compounds (hydroxytyrosol, tyrosol and oleuropein) and tocopherol – and the antioxidant activity in different fractions (flesh, stone and seed) from the table olive by‐product and the whole by‐product. The highest amounts of phenolic compounds (1710.0 ± 33.8 mg kg?1) as well as the highest antioxidant activity (8226.9 ± 9.9 hydroxytyrosol equivalents mg kg?1) were obtained in the seed. The highest amounts of hydroxytyrosol (854.8 ± 66.0 mg kg?1) and tyrosol (423.6 ± 56.9 mg kg?1) were found in the whole by‐product from the pepper stuffed olives, while the stone without seed had the maximum oleuropein content (750.2 ± 85.3 mg kg?1). α‐Tocopherol values were between 79.8 ± 20.8 mg kg?1 in the seed of the olive stone and 6.2 ± 1.2 mg kg?1 in the whole by‐product from the anchovy‐stuffed olives. In light of the results obtained, it would seem possible to use table olive by‐product as a source of natural antioxidants in foods, cosmetics or pharmaceutical products, thus contributing to diminishing the environmental impact of table olive by‐product and to its revalorisation. 相似文献
48.
49.
Currently available treatments for the degenerated intervertebral disc present disadvantages, such as surgical invasiveness and inadequate load distribution results. Load-bearing, injectable materials may be interesting for future therapies, but have not been studied in depth. In this study, the existing literature was screened for studies on injectable materials for the intervertebral disc and a rationale for load-bearing, injectable materials was formulated. Requirements for such a material were discussed, partly based on the experience of materials used for similar applications. Important properties were discussed and found to include biocompatibility, bioactivity, porosity, handling, injectability, working time, setting time, radiopacity, containment and mechanical properties, where several of these properties are linked to one another. In conclusion, there is a need for consensus on the properties of new materials developed for use in minimally invasive procedures in the spine. A substantial amount of attention may need to be given to non-toxic setting reactions. 相似文献
50.
Tania Maree 《International journal of human-computer interaction》2017,33(12):963-972
The growing importance of social media and research interest in the field makes it imperative to consider the measures used to assess social networking site (SNS) use. The Facebook Intensity Scale has seen prolific use since its development; however, it has been criticized by some scholars. Jenkins-Guarnieri, Wright, and Johnson (2013) suggested another scale, the Social Media Use Integration Scale (SMUIS), which was developed to be suitable for use across different SNS platforms. They advised further research to confirm its psychometric properties, testing it on a more diverse sample than US college students and on social media other than Facebook. In this study, EFAs and a CFA were conducted to examine the validity of the SMUIS on Facebook and LinkedIn in the African context. The results provide preliminary evidence of the reliability and validity of the SMUIS for diverse age ranges. Further testing of the scale on LinkedIn is recommended. 相似文献