1,721,127 research outputs found
Improved method for the determination of furosine in food by capillary electrophoresys
No full textA previously described method for determination of furosine by capillary zone electrophoresis in food has been improved for greater accuracy and sensitivity. Acid-hydrolysed samples are subjected to solid phase extraction, then dried and redissolved before injection. Electrophoretic separation is performed in a fused silica capillary tube (50 mum inside diam.) with an extended-path-length detection cell using a 3-(N-morpholino)-2-hydroxypropanesulphonic acid solution at pH 7.0 as run buffer. The in-laboratory repeatability was within +or-7.1% at the 95% confidence level when the amount of furosine ranged between 8 and 250 mg/100 g protein. The value of both repeatability and sensitivity fulfill the requirements stated in the EU and Italian regulations for furosine determination in pasteurized milk and Mozzarella cheese. The data obtained on 48 different food samples including heat-treated milk, cheeses and durum wheat products were comparable with those obtained by an HPLC method and proved to be accurate for furosine values up to at least 400 mg/100 g protein. The furosine values found in cultured fresh cheese samples suggest that the use of this furosine index holds promise for the characterization of this type of cheese
Andamento della concentrazione di glutatione durante la vinificazione
No full textIl glutatione ridotto può svolgere in mosto e vino numerose attività tra le quali quella
antiossidante. In questo modo risultano sfavoriti l’imbrunimento e lo sviluppo di
difetti sensoriali. Il livello di glutatione è stato monitorato in numerose vinificazioni
su scala industriale nelle annate 2009 e 2010. La presenza di tale composto
risulta essere dipendente dalla pressatura, dal contenuto di rame e dall’esposizione
all’ossigeno del mosto. Il ceppo di lievito impiegato influenza debolmente la
concentrazione di glutatione se il quantitativo di azoto prontamente assimilabile
del mosto è adeguato.The reduced glutathione can carry out several activities in must and wine, such as the antioxidant property. In this way, the formulation of both browning and unpleasant flavours is slowed down. The glutathione level was monitored in several winemaking process performed in industrial condition for the 2009 and 2010 vintages. The glutathione level is affected by the pressing, the copper concentration and the oxygen exposure of must. The yeast strains shows a weak influence on the glutathione amount is the readily assimilable nitrogen is adequate in must
MONITORING OF GLUTATHIONE CONCENTRATION DURING THE WINEMAKING
No full textThe reduced glutathione can carry out several activities in must and wine, such as the antioxidant property. In this way, the formation of both browning and unpleasant flavours is slowed down. The glutathione level was monitored in several winemaking processes performed in industrial condition for the 2009 and 2010 vintages. The glutathione level is affected by the pressing, the copper concentration and the oxygen exposure of must. The yeast strain shows a weak influence on the glutathione amount if the readily assimilable nitrogen is adequate in must
Monitoring of glutathione concentration during winemaking by a reliable high-performance liquid chromatography analytical method
No full textBackground and Aims: Glutathione (GSH) is valued in winemaking as an effective antioxidant in must and white wine if its concentration exceeds a few milligrams per litre. We report the further improvement of a previous analytical method for GSH quantification and its application to the analysis of grapes and wines. Methods and Results: Glutathione was derivatised with p-benzoquinone and detected by HPLC/UV. The analytical method was sensitive (limit of quantification, 0.43mg/L), linear (R2>0.997), accurate (recovery, 101% in grape juice and white wine) and repeatable (relative standard deviation, 3.1). The monitoring of vinifications at commercial wineries showed that Saccharomyces cerevisiae was a main source of GSH in wine, since the GSH of the grape was poorly preserved following juice preparation. Glutathione concentration decreased during wine aging on yeast lees. Conclusion: Glutathione concentration varied considerably during winemaking, and thus monitoring is essential for improving wine flavour and preventing oxidation. This method is suitable for this purpose. Significance of the Study: The analytical method proposed is reliable, fast and easy-to-apply and allows the assessment of the GSH in grape, must and wine. The strong role of the yeast on the GSH concentration in wine is reported
Determination of furosine in dairy products by capillary zone electrophoresis: A comparison with the HPLC method
No full textA procedure for determining furosine in milk and dairy products by capillary zone electrophoresis (CZE) with UV detection at 280 nm wavelength is described. The performance by CZE was compared with that of the IP-RP HPLC method in different samples of heat-treated milk and Mozzarella cheese. The hydrolyzed sample was dried under vacuum in order to remove the hydrochloric acid, dissolved with phosphate buffer at pH 8.0 and injected onto a fused-silica capillary (72 cm x 50 mu m i.d.). Furosine migration occurred without interference in approximately 6.5 min, with a signal-to-noise ratio of 5 for a 100 fmol peak. The CZE method gave a linear response (r = 0.997) for the furosine with the values ranging from those of pasteurized milk to those of indirect UHT milk, The repeatability (RSD < 3%) was close to that of the HPLC method, Nevertheless, a comparison between the 2 methods proved that low levels of furosine (from 5 to 12 mg/100 g protein) were underestimated by CZE, This limitation indicates that CZE of furosine is still not suitable for the official testing of pasteurized milk and Mozzarella cheese but, its rapidity and low cost of analysis, makes it attractive for routine in-house work
Determinazione del latte di vacca nei formaggi di specie minori : applicazione ai formaggi di capra
No full textWine making and re-fining in earthenware containers. An ancient practice still alive and fruitful
No full textWine is one of the most important agro-food products in Europe, and in Italy in particular where more than 48 million of hectoliters are produced each year. The quality of wine is due to several factors, related both to agronomic, and technological aspects; among these lasts the hygienic conditions of grapes and facilities, the process of wine making, the refining steps, the bottling and the storage conditions are prevalent. A renewed interest for the traditional, porous containers, like earthenware jars, has been recently noted in Italy and in France, and in this work preliminary results of a study undertaken in order to describe and understand the role of these clay tanks in wine making and re-fining, are presented. The differences between a 2 years old Cerasuolo wine (a typical wine produced in the southeastern Sicily) produced and re-fined in earthenware 250-400 l jars (amphora) and the same wine obtained by means of the current technology, were evaluated both by a chemical and a sensory point of view. Noticeable, but not very big, differences were observed between the two wines and all of them can be reasonably correlate to the specific performance of the clay tanks used, in terms of oxygen permeability, heat insulation and, possibly, of microorganisms selection
Le deformita’ dell’ arto superiore e inferiore e loro patogenesi
No full textLa patogenesi delle deformità dell’arto inferiore e superiore nelle pci
Essa è legata ai seguenti fattori:
- lo squilibrio muscolare con riduzione della motilità spontanea dei primi mesi di vita
- il carico, necessario per la maturazione dello scheletro, se viene assunto tardivamente o in maniera
inadeguata
- le posture, in particolare quella quadrupedica e quella assisa
- l’asimmetria (neuromotoria e meccanica).
Le conseguenze della influenza di questi fattori sono: l’ipertono, la contrattura-fibrosi e la retrazione
dei muscoli investiti dalla spasticità, da soli o variamente raggruppati, mentre a livello articolare si ha la
perdita del normale rapporto con riduzione del movimento articolare necessario alla morfogenesi dei capi
ossei.
In queste condizioni, inoltre, i muscoli antagonisti vengono progressivamente e sempre più
penalizzati, sia per la loro sovradistensione, sia per il loro non uso.
Questi fattori influenzano l’insorgenza di atteggiamenti patologici e deformità osteoarticolari di
entità variabile in rapporto alla forma motoria della pci, all’entità del danno, al livello funzionale, alla
possibilità di attuare tutte le strategie preventive.
Classicamente agli arti inferiori abbiamo atteggiamenti patologici a partire dal bacino (obliquità
pelvica = triade maligna) nelle tetraplegie; per l’anca sono possibili quadri di displasia o sublussazione o
lussazione nelle tetraplegie e diplegie di gravità variabile, semplici atteggiamenti in adduzioneintrarotazione
per alterato angolo di antiversione nelle diplegie ed emiplegie; per il ginocchio flessione
(tetraplegie e diplegie) iperestensione o rigidità in estensione (diplegie) con associazione di varo-valgo; per
il piede sono possibili deformità semplici o complesse.
Le deformità dell’arto superiore sono legate allo squilibrio muscolare, inteso come espressione di
schemi patologici presenti nella esecuzione del movimento, ai disturbi della sensibilità, molto meno
all’influenza della gravità; anche per questo segmento sono previsti atteggiamenti patologici tipici: flesso–
adduzione–intrarotazione della spalla, flessione del gomito, pronazione dell’avambraccio, flessione e
deviazione ulnare del polso, flessione delle dita, interposizione del pollice. Tali atteggiamenti-deformità
hanno una manifestazione variabile in rapporto alla forma motoria e sono valutate in rapporto al disturbo
funzionale con il quale si presentano
Determination of Reduced Cysteine in Oenological Cell Wall Fractions of Saccharomyces cerevisiae
No full textCompounds containing cysteine residues, such as glutathione, can affect the redox potential of must and wine by reduction of o-quinones and hydrogen peroxide. The oenological yeast cell wall fractions contain cysteine residues in their protein structure, and they could affect both oxidative and odor properties of wine. An analytical approach based on the derivatization of cysteinyl residues with p-benzoquinone followed by reversed-phase high-performance liquid chromatography separation was developed to quantify glutathione and free and protein cysteine in 16 Saccharomyces cerevisiae strains and 12 commercial samples of yeast mannoproteins, hulls, and lysates. The chemical modifications induced by the Mail lard reaction following the industrial preparation of such fractions were evaluated as well. Lysates showed the highest protein cysteine content and high contents of glutathione and free cysteine. Mannoproteins showed an intense Mail lard reaction (furosine >60 mg/100 g protein), and most of the samples were able to bind thiol compounds with a potentially detrimental effect toward the thiol-related odors in wine
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