1,720,966 research outputs found
Rilevamento quantitativo dell'imbrunimento del vetro trattato con raggi gamma. Nota II - Applicazioni pratiche
No full textAntioxidant activity of tomato lipophilic extracts and investigationon interactions between carotenoids and alpha-tocopherol in synthetic mixtures
No full textIn the present study we assayed the antioxidant activity of lipophilic extracts obtained from different tomato varieties. The results showed that cherry tomatoes, characterized by a high carotenoid content, had the highest antioxidant activity. A quantitative analysis of lycopene, b-carotene, lutein and
a-tocopherol was also performed and the correlation between the antioxidant content and the antioxidant activity was estimated. The highest correlation coefficient was found for lycopene (R2=0.9236,P< 0.001). The analysis of two-component mixtures containing a-tocopherol and carotenoids showed that significant synergism occurred for all the combinations which contained a-tocopherol and b-carotene mixed together. The highest synergistic effects were detected for a-tocopherol-lycopene
mixtures, which were the most efficient combinations tested in the present study. The analysis of the carotenoid combinations indicated that synergism occurred for lycopene-b-carotene, lycopene-lutein and lutein-b-carotene mixtures. The analysis of four-component mixtures did not show statistically significant synergistic effects
Composizione quali-quantitativa della frazione fenolica dell'olio di oliva.
No full textVolume: Atti del 6° Congresso Nazionale di Chimica degli Alimenti.
Casa Editrice: Taro (Alessandria- Italia)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Lc/Esi/Ms/Ms determination of postharvest fungicide residues in citrus juices
No full textAn LC-ESI-MS/MS method was developed for the quantitative detection of postharvest fungicide residues in citrus juices and reported in this paper. The analyses of thiabendazole (TBZ), carbendazim (MBC), thiophanate methyl (TPM), imazalil (IMZ) and prochloraz (PCZ) residues were performed by using a gradient elution in conjunction with positive ionization mode electrospray ionization tandem mass spectrometry. Fungicides were extracted from citrus juices with recoveries ranging from 79.8 to 101.2% and relative standard deviation better than 15%. The quantification limits ranged from 0.01 μg/kg IMZ to 0.06 μg/kg for MBC. The LC-MS-MS method was applied to commercial citrus juices, detecting MBC, TBZ and IMZ residues in the 90% of the samples. Prochloraz residues were detected only in one of the multifruit juice (orange, lemon and carrot) samples
Quantitative variation of the main carotenoids in Italian tomatoes in relation to geographic locations, harvesting time, varieties and ripening stages
No full textThe aim of this study was to evaluate if the carotenoid content of Italian tomatoes is affected by factors such as the geographical area in which the plants are cultivated, harvest time, tomato typology and ripening stage. Three Italian tomato varieties were sampled in different geographical locations throughout Italy in the summer and winter months. Significant differences were found in the lycopene, beta-carotene and phytoene contents as a function of tomato variety with the highest carotenoid levels recorded for cherry tomatoes. In relation to the geographic location the only significant differences were lycopene content in salad tomatoes. The harvesting period influenced carotenoid composition, but a definite seasonal trend was not observed. During the summer the lycopene content was higher in summer-harvested tomatoes than in winter-harvested ones, for both cluster and cherry typologics. In relation to the harvesting season, no significant differences were found for the lycopene content in salad tomatoes, while the beta-carotene content was significantly different. Ripening stage influenced lycopene and carotene levels in all the varieties considered; significant differences in the phytoene values were found in cherry tomatoes. The highest carotenoid levels were recorded in fully ripe cherry tomatoes
Dati preliminari sulla composizione chimica e l'attività antiossidante dei frutti di Solanum sisymbriifolium Lam. coltivato in Italia
No full textValidazione di un metodo HPLC per il controllo dei conservanti nei prodotti cosmetici: confronto con i metodi ufficiali.
No full textIl lavoro ha riguardato la validazione di un metodo interno in grado di determinare contemporaneamente i conservanti presi in considerazione dai Decreti Ministeriali analizzabili in HPLC: acido benzoico, acido 4-idrossibenzoico, acido sorbico, acido salicilico, 2-fenossietanolo, 1-fenossipropan-2-olo, metile, etile, propile, butile e benzile 4-idrossibenzoato (escluso l'acido propionico analizzabile gascromatografiamente). Tale metodo permette anche la determinazione di un ulteriore conservante spesso utilizzato come l'acido deidroacetico
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