Several cultivars of strawberries (Fragaria sp.), grown under different conditions, were analyzed by both sensory and instrumental methods. The overall appreciation, as expressed by consumers, was ...mainly reflected by attributes such as sweetness and aroma. No strong correlation was obtained with odor, acidity, juiciness, or firmness. The sensory quality of strawberries can be assessed with a good level of confidence by measuring the total sugar level (°Brix) and the total amount of volatile compounds. Sorting out samples using the score obtained with a hedonic test (called the “hedonic classification method”) allowed the correlation between consumers' appreciation and instrumental data to be considerably strengthened. On the basis of the results obtained, a quality model was proposed. Quantitative GC-FID analyses were performed to determine the major aroma components of strawberries. Methyl butanoate, ethyl butanoate, methyl hexanoate, cis-3-hexenyl acetate, and linalool were identified as the most important compounds for the taste and aroma of strawberries. Keywords: Strawberry; Fragaria sp.; quality; total volatiles; SPME; sensory evaluation; hedonic; flavor; aroma
A rapid method for determining the freshness of the harvested fish is presented. The volatile amines, which are liberated during the storage of the fish have been quantified using a SPME direct ...method. This new method consist of an injection port of a gas-chromatograph linked by a short capillary to a detector. We have utilized standard chromatographic detectors, either FID or NPD. The volatile compound are adsorbed on a SPME-fiber and desorbed in the injector. The peaks are evaluated either by their area or the height.
We have monitored the storage of salmon and whiting over a period of 20 days. Two different methods for preparing the fish samples have been evaluated: (1) the basification of a minced sample of fish directly in the vial without other preparation; (2) the standard TVB extraction procedure followed by basification in a head space vial.
The response of the detector was standardized using aqueous trimethylamine solutions. The results show a good correlation between the time of conservation on ice of the fish and the measured signal either with the FID or with the NPD detector. The method allows a high throughput of samples with minimal manipulation.
The amount of total volatile compounds, total acidity, total sugar content (degrees Brix) and fruit firmness were used to characterize the degree of ripeness of three strawberry varieties (Carezza, ...Darselect and Marmolada). A novel concept using solid phase microextraction (SPME) and measurement of total volatile compounds to distinguish between various stages of strawberry ripeness was applied. The carboxene/polydimethylsiloxane SPME fibre was found to be best suited to differentiate between the stages of ripeness. The amount of total volatile compounds rapidly increased near to maturity (between the three-quarters red stage and the dark-red stage). Most of the volatile compounds identified were esters, followed by aldehydes, and alcohols. The most abundant volatile compounds were propyl butanoate, 3-phenyl-1-propanol, butyl butanoate, isobutyl butanoate, 3-methyl butyl butanoate and isopropyl hexanoate. The concentration of green aroma components such as hexanal, trans-2-hexenol and cis-3-hexenyl acetate progressively decreased during the maturation process until they became minor components in mature strawberries.PUBLICATION ABSTRACT
The quality of tomato and apricot cultivars was assessed by sensory evaluation, consumer tests and instrumental methods.
The overall sensory appreciation of tomatoes was mainly reflected by ...attributes such as “sweetness”, “aroma”, “juiciness” and “firmness”. Hedonic classification of samples allowed to significantly improve the correlation between instrumental data and consumer appreciation. Instrumental measurements were focused on total sugar content (°Brix) and total amount of volatile compounds and texture (firmness). For tomatoes the CAR/PDMS fibre and for apricots the PDMS fibre were used for the analysis of total volatiles.
The results obtained with tomatoes and apricots confirmed the applicability of the quality assessment model developed for evaluation of the quality of strawberries.
The Experiment Control System (ECS) of the LHCb Silicon Tracker sub-detectors is built on the integrated LHCb ECS framework. Although all LHCb sub-detectors use the same framework and follow the same ...guidelines, the Silicon Tracker control system uses some interesting additional features for operation and monitoring. The main details are described in this document. Since its design, the Silicon Tracker control system has been continuously evolving in a quite disorganized way. Some major maintenance activities are required in order to keep improving it. A description of those activities can also be found here.
First operational experience from the LHCb Silicon Tracker Gallas, A.; Bay, A.; Blanc, F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2011, Letnik:
636, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The LHCb Silicon Tracker is a silicon micro-strip detector covering a sensitive area of 12
m
2 with a total of 272k readout channels. The installation of the detector is complete and commissioning is ...making excellent progress. The detector has recorded first beam-induced events during LHC synchronization tests in August 2008 and in June 2009. These events have allowed the performance to be studied, and adjustments to the operational parameters to be made. In this contribution, we will draw first lessons from the in situ commissioning of the Silicon Tracker, and present results from the reconstruction of data collected during the LHC synchronization tests.
Installation and operation of the LHCb Silicon Tracker detector Esperante, D.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2010, Letnik:
623, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The LHCb experiment is designed to perform high-precision measurements of CP violation and rare decays of B hadrons. The construction and installation of the Silicon Tracker (ST) was completed by ...early summer 2008. The Silicon Tracker covers a sensitive area of about 12m2 using silicon micro-strip technology and must withstand a radiation dose of 5×10131MeVn/cm2 equivalent after 10 years of operation. In these proceedings the preparation of the detectors for the first LHC beams is reported. Selected results from the detector commissioning in LHCb are shown, including the first beam-related events accumulated during the LHC injection and synchronization tests in September 2008. Lessons are drawn from the experience gathered during the installation and commissioning.
We give here a short review of the LHCb Silicon Tracker, the main points of the module production and quality control, followed by the commissioning of the detector. Problems that were found during ...production or commissioning are described and the first performance assessment of the installed detector with “beam data” is given.
Petite Arvine is a white grape variety that grows exclusively in the canton of Valais in Switzerland and is used to produce a typical regional wine. In order to elucidate the nature of the flavour ...compounds that contribute to the characteristic aroma of this wine, the organic extracts were analysed by gas chromatography and olfactometry. The olfactometrically detected zones were further compared with the odour of extracts of vegetal material. 3-Mercaptohexanol, β-ionone and other compounds were identified as main contributors to the characteristic aroma of Petite Arvine wine.
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