Search results for "Drying"

Identification of lipid binders in old oil paintings by separation of 4-bromomethyl-7-methoxycoumarin derivatives of fatty acids by liquid chromatogr…

2005

A HPLC-fluorescence method for identification of drying oils from binding media or protective film used in pictorial works of art prior to conservation or restoration is proposed. Fluorescence derivatization of fatty acids released by hydrolysis of structural drying oils is studied. The derivatization reagent was 4-(bromomethyl)-7-methoxycoumarin with 18-crown-6 as catalyst. Mobile phase was programmed from methanol-water (90:10 v/v) to methanol-water (100:0 v/v) in 25 min. The excitation and emission wavelengths were 325 and 395 nm, respectively. Under these chromatographic conditions, coumarin derivatives of myristic, palmitic, oleic and stearic acids were satisfactorily resolved. The met…

Encapsulation of Alcohol Dehydrogenase in Mannitol by Spray Drying

2014

The retention of the enzyme activity of alcohol dehydrogenase (ADH) has been studied in various drying processes such as spray drying. The aim of this study is to encapsulate ADH in mannitol, either with or without additive in order to limit the thermal denaturation of the enzyme during the drying process. The retention of ADH activity was investigated at different drying temperatures. When mannitol was used, the encapsulated ADH was found inactive in all the dried powders. This is presumably due to the quick crystallization of mannitol during spray drying that resulted in the impairment of enzyme protection ability in comparison to its amorphous form. Maltodextin (dextrose equivalent = 11)…

Old World Megadroughts and Pluvials During the Common Era

2015

An atlas of megadroughts in Europe and in the Mediterranean Basin during the Common Era provides insights into climate variability.

Toxicity assessment of pesticides using the microtox test: application to environmental samples.

1997

Flame-burned stainless steel wire spheres as carriers ofZymomonas mobilis cells and extracellular levansucrase

1999

In the present work, the use of flame-burned WS as carriers of Z. mobilis and extracellular levansucrase and the effect of the cell fixation method by dehydration on system productivity were investigated. Lyophilization and convective drying of Z. mobilis biomass at 30°C to a moisture content of 10–14% gave the best results for the repeated batch fermentations of a sucrose medium to obtain levan and ethanol. Significant correlation between the product formation and the concentration of free cells in the fermentation medium was established. Clearly, the cells were weakly bound to the newly generated WS and were washed out into the medium during fermentation. Here the hypothesis is presented …

Effect of Pulsed Electric Field Pretreatment on Drying Kinetics, Color, and Texture of Parsnip and Carrot.

2018

The aim of the study was to evaluate the effect of pulsed electric field (PEF) pretreatment on drying kinetics and on color and textural changes in sliced parsnip and carrot. Cell disintegration index measured in parsnips after PEF pretreatment significantly differed from the ones measured for carrots and, consequently, the reduction of the time needed to dry both samples to a final moisture content up to 5% (wet basis). The drying time of the PEF pretreated parsnip was reduced by up to 28% at 70 °C and by up to 21% at 60 °C in carrot, in comparison to untreated samples. The PEF pretreatment influenced the effective diffusivity of water into the samples going from 50 °C to 70 °C: in carrots…

The impact of pulsed electric fields on quality parameters of freeze‐dried red beets and pineapples

2020

EPR Studies of Oxidation of Iron and Free Radicals Formation after Dessication of Oxyhemoglobin by Freeze-Drying and Spray-Drying

1992

Dans les Centres de Transfusion Sanguine, les hematies a peremption sont inutilisables. Elles peuvente transformees en solution d’hemoglobine en vue d’une utilisation potentielle pour transfuser, mais cela suppose, pour ce type de produit sanguin que les problemes de conservation resultant de l’oxydation de Fe(II) de I’heme soient resolus. Pour minimiser ce phenomene, on a voulu dessecher des preparations d’hemoglobines seules ou en presence de protecteur par differentes techniques a caractere industriel en vue d’etudier les produits formes au cours de ces traitements de dessiccation.

Effect of pretreatments and drying processo on health-promoting components of goji berries

2020

Drying is one of the most common preservation methods used to extend the shelf life of fruits and vegetables by reducing water content so as to prevent the growth and reproduction of microorganisms and to inactivate many of the moisture-mediated alterative reactions. Goji berries are mainly consumed dried. Several methods can be used to dry goji berries, such as sun drying, hot air drying, vacuum drying, and freeze drying. In this chapter the most used pre-treatment and drying processes found in literature on goji berries are described, together with their effect on their health promoting components, such as carotenoids, tocols, vitamin C, flavonoids and phenols. Moreover the effect of diff…

Evolution of Carotenoid Content, Antioxidant Activity and Volatiles Compounds in Dried Mango Fruits (Mangifera Indica L.)

2020

The aim of this research was to study the evolution of carotenoid compounds, antioxidant &beta