Search results for "Pretreatment"

Molecularly Imprinted Polymers as Useful Sorbents for Bioanalysis

2022

The determination of various active compounds in different types of biological samples attracts recently considerable attention. Unfortunately, the complexity of such sample matrices requires the application of multistage analytical procedures, which by many analysts is considered the most critical step in the whole analytical process. Sample preparation techniques dedicated to bioanalysis must ensure effective isolation and enrichment of various, often trace, amounts of analytes. Furthermore, the high selectivity of extraction of the target analytes, in relation to other interfering substances co-presented in the sample, is important in this case. Therefore, over the last two decades, the …

Assessment of Postharvest Dehydration Kinetics and Skin Mechanical Properties of “Muscat of Alexandria” Grapes by Response Surface Methodology

2016

The dipping of berries in a dilute solution of sodium hydroxide during a short time was evaluated as pretreatment undertaken prior to convective dehydration of wine grapes. The impact of the sodium hydroxide content and dipping time on weight loss (WL) at different dehydration times was thoroughly assessed using central composite design (CCD) and response surface methodology (RSM). Furthermore, the effects of these two variables were also investigated on the skin mechanical properties of dehydrated grapes. The effect of these two pretreatment factors on the dehydration kinetics and skin hardness was satisfactorily fitted to regression models. The berry pretreatment with low sodium hydroxide…

Cryopreservation of Limonium serotinum apical meristems from in vitro plantlets using droplet-vitrification

2011

Abstract In this study in vitro shoot tips of a Sicilian genotype of Limonium serotinum were successfully cryopreserved using the droplet-vitrification technique. Growth recovery of cryopreserved shoot tips was possible only when samples were pretreated for 16 h in liquid medium with 0.3 M sucrose, then for 5 h in liquid medium with 0.7 M sucrose before performing the cryopreservation protocol. Optimal conditions included treatment for 20 min in a loading solution containing 1.9 M glycerol + 0.5 M sucrose, treatment with vitrification solution B5 (glycerol 40.0%, sucrose 40.0%, w/v) for 60 and 90 min or vitrification solution A9 (glycerol 30.0%, dimethylsulfoxide 20.0%, ethylene glycol 20.0…

Ligninolytic potential of Curvularia kusanoi L7 laccases for animal production

2020

The present research was conducted with the objective of evaluating the ligninolytic potential of Curvularia kusanoi L7 laccases in improving the nutritional quality of fibrous substrates for animal feed. Laccase production was obtained from C. kusanoi L7 under native conditions by solid submerged fermentation of wheat bran and by biological interactions with Trichoderma viride M5-2 and Trichoderma pleuroticola. The enzymes were purified from the culture broths by triphasic partition. The degradative potential of native and induced laccases where evaluated by determining foliar lignololytic capacity, raw wheat (Triticum aestivum) straw delignification and the effect of enzyme pretreatment o…

Semi-Continuous Lab-scale Plant for Hydrothermal or Organosolv Treatment of Lignocellulosic Biomass

2013

Lignocellulosic biomass is increasingly being considered as a potential alternative source for both fuels and goods production. In order to better address the starting material to higher conversion and selectivity in the desired products, the possibility to selectively control the dissolution of the three main constituents of the matrix (hemicellulose, cellulose and lignin) should be pursued. As the three biopolymers are intimately connected one another, a suitable pretreatment step could help the effectiveness of the whole process, by producing cleavage of the biomacromolecules interconnecting bonds and by starting their depolymerization . In this frame, we developed a semi-continuous lab-…

Effect of sodium borohydride and hydrogen peroxide pretreatments on soda pulping of sugar maple (Acer saccharum)

2021

For recovering value-added wood-based organic material prior to delignification, sodium borohydride (NaBH4) and hydrogen peroxide (H2O2) pretreatments under alkaline conditions were performed before soda pulping of sugar maple (Acer saccharum) chips with sodium hydroxide (NaOH). In this investigation, it was determined whether the pulp yield could be increased by partly stabilizing the hemicelluloses by these pretreatments, and simultaneously obtains lower pulp kappa numbers. The results indicated that when aiming to the same kappa numbers (i.e., kappa numbers 14.3-20.5), roughly 3% higher pulp yield could be achieved if the chips were pretreated with alkaline 0.5% NaBH4 solutions, compared…

Electrochemistry of methylene blue at an alkanethiol modified electrode

2012

International audience; Gold surfaces were derivatized with decanethiol. The electrochemistry of methylene blue at these modified electrodes was investigated in function of the gold cleaning process and compared with the results obtained at a bare gold electrode. Cyclic voltammetry at low methylene blue concentrations (c(MB) <= 16 mu M) yielded surface behavior data. The properties of the film vary with the electrode pretreatment. Without electrochemical cleaning step, the standard potential at a gold electrode modified with 1-decanethiol is nearly the same as on a bare gold electrode. On the other hand, when the electrode is electrochemically cleaned before adsorption of the alkanethiols, …

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…

Liquid hot water pretreatment of Arundo Donax: a comparison between batch and a flow-through systems

2014

Thermal Decomposition and Combustion of Microwave Pre-Treated Biomass Pellets

2021

The objective of the study was to investigate a more effective use of commercially available biomass pellets (wheat straw, wood, peat) using microwave pretreatment to improve heat production. Pellets were pretreated using the originally designed microwave torrefaction device. The effects of microwave (mw) pretreatment were quantified, providing measurements of the weight loss and elemental composition of pellets and estimating the effect of mw pretreatment on their porosity, surface area and calorific values at pretreatment temperatures of T = 448–553 K. Obtained results show that the highest structural variations and elemental composition during mw pretreatment were obtained for wheat stra…