The Effect of Structure and Imbibition Mode on the Rehydration Kinetics of Freeze-dried Carrots

2013 ◽  
pp. 112-121 ◽  
Author(s):  
F.J. Vergeldt ◽  
A.J. Duijster ◽  
R.G.M. van der Sman ◽  
A. Voda ◽  
S. Khalloufi ◽  
...  
Keyword(s):  
Freeze Dried ◽  
Kinetics Of ◽  
Effect Of Structure

Degradation kinetics of anthocyanins in freeze-dried microencapsulates from lowbush blueberries (Vaccinium angustifoliumAiton) and prediction of shelf-life

2016 ◽  
Vol 34 (10) ◽  
pp. 1175-1184 ◽  
Author(s):  
Giovana Bonat Celli ◽  
Rojin Dibazar ◽  
Amyl Ghanem ◽  
Marianne Su-Ling Brooks
Keyword(s):  
Shelf Life ◽  
Degradation Kinetics ◽  
Freeze Dried ◽  
Kinetics Of

scholarly journals Morphology and Release Kinetics of Protein-Loaded Porous Poly(L-Lactic Acid) Spheres Prepared by Freeze-Drying Technique

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Takashi Sasaki ◽  
Kazuki Tanaka ◽  
Daisuke Morino ◽  
Kensuke Sakurai
Keyword(s):  
Lactic Acid ◽  
Freeze Drying ◽  
Release Kinetics ◽  
Particle Surface ◽  
Spherical Particles ◽  
Freeze Dried ◽  
Model Drug ◽  
Drug Compound ◽  
Kinetics Of ◽  
Step Mechanism

Freeze-drying a biodegradable polymer, poly(L-lactic acid) (PLLA), from 1,4-dioxane solutions provided very porous spherical particles of ca. 3 mm in radius with specific surface area of 8–13 m2 g−1. The surface of the particle was found to be less porous compared with its interior. To apply the freeze-dried PLLA (FDPLLA) to drug delivery system, its morphology and drug releasing kinetics were investigated, bovine serum albumin (BSA) being used as a model drug compound. Immersion of FDPLLA into a BSA aqueous solution gave BSA-loaded FDPLLA, where mass fraction of the adsorbed BSA reached up to 79%. Time-dependent release profile of BSA in water suggested a two-step mechanism: (1) very rapid release of BSA deposited on and near the particle surface, which results in an initial burst, and (2) leaching of BSA from the interior of the particle by the diffusion process. It was suggested that the latter process is largely governed by the surface porosity. The porosity of both the interior and surface was found to decrease remarkably as the concentration of the original PLLA/1,4-dioxane solution increases, C0. Thus, C0 is a key parameter that controls the loading and releasing of BSA.

Reentanglement Kinetics of Freeze-Dried Polymers above the Glass Transition Temperature

2012 ◽  
Vol 45 (16) ◽  
pp. 6648-6651 ◽  
Author(s):  
Chao Teng ◽  
Yun Gao ◽  
Xiaoliang Wang ◽  
Wei Jiang ◽  
Chen Zhang ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Freeze Dried ◽  
Kinetics Of

Analysis of Freeze-Drying and Rehydration of Açai (Euterpe oleracea Martius)

2015 ◽  
Vol 365 ◽  
pp. 11-16
Author(s):  
R.J. Brandão ◽  
M.M. Prado ◽  
L.G. Marques
Keyword(s):  
Mass Transfer ◽  
Energy Demand ◽  
Freeze Drying ◽  
Moisture Diffusion ◽  
Euterpe Oleracea ◽  
Power Ultrasound ◽  
Ultrasound Waves ◽  
Freeze Dried ◽  
Peleg’S Equation ◽  
Kinetics Of

The freeze-drying rate is essentially low, since it is controlled by internal moisture diffusion. In addition, the application of vacuum and low temperature during the process presents a higher energy demand. Therefore, the search for new strategies to improve water mobility during freeze-drying constitutes a topic of relevant research. The aim of this work was to evaluate the use of power ultrasound to improve freeze-drying characteristics of açai, quantifying the influence of the applied power on both the drying and rehydration kinetics of the material. Açai (Euterpe oleracea Martius) samples were sonicated with two different frequency levels, 20 kHz and 40 kHz, and two sonication times, 3 min and 10 min. Page’s equation considering internal and external resistances to mass transfer provided a good fit of freeze-drying kinetics, while the Peleg’s equation was found to be suitable for describing the rehydration kinetics of freeze-dried açai. Pretreatment of açai with ultrasound waves was not effective. Ultrasound-induced structural disruption in the açai skin hindered the mass transfer during both freeze-drying and rehydration processes.

Solid state amorphization in Ni–Ti systems: the effect of structure on the kinetics of interface and grain-boundary amorphization

1998 ◽  
Vol 46 (15) ◽  
pp. 5491-5508 ◽  
Author(s):  
R. Benedictus ◽  
K. Han ◽  
C. TrÆholt ◽  
A. Böttger ◽  
E.J. Mittemeijer
Keyword(s):  
Solid State ◽  
Grain Boundary ◽  
Kinetics Of ◽  
State Amorphization ◽  
Effect Of Structure

Kinetics of the decomposition of freeze-dried iron(II) sulfate

1971 ◽  
Vol 75 (9) ◽  
pp. 1179-1185 ◽  
Author(s):  
David Wilfred Johnson ◽  
P. K. Gallagher
Keyword(s):  
Freeze Dried ◽  
Kinetics Of

scholarly journals Rehydration properties of hybrid method dried fruit enriched by natural components

2018 ◽  
Vol 32 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Hanna Kowalska ◽  
Agata Marzec ◽  
Jolanta Kowalska ◽  
Agnieszka Ciurzyńska ◽  
Kinga Samborska ◽  
...  
Keyword(s):  
Raw Material ◽  
Air Drying ◽  
Dried Fruits ◽  
Microwave Vacuum Drying ◽  
Freeze Dried ◽  
Fruit Samples ◽  
Dried Fruit ◽  
Juice Concentrate ◽  
The Impact ◽  
Kinetics Of

Abstract The aim of the study was to determine the impact of osmotic pre-dehydration and drying of fruit on the rehydration properties of dried fruit. Herein, the effect of fruit juice, applied as a natural enriching substance was very important. In addition, the properties of dried fruits obtained through combined air-drying and subsequent microwave-vacuum drying with ‘puffing’ effect were similar to the freeze-dried fruits, but showed other rehydration properties. As raw material, frozen strawberry (Honeoye variety) and fresh apples (Idared variety) were used in the study. The apples and partially defrosted strawberries were prior dehydrated in solutions of sucrose and a mixture of sucrose with chokeberry juice concentrate at 50°C for 2 h. Next, the fruit samples were dried by one of two ways: air-drying (50°C, 5 h) and microwavevacuum drying for about 360 s; and freeze-drying (30°C, 63 Pa, 24 h). The rehydration was carried out in distilled water (20°C, 5 h). The osmotic pre-dehydration hindered fruit drying process. The impact of drying method became particularly evident while examining the kinetics of rehydration. During the rehydration of the pre-dehydrated dried fruit a slower hydration could be observed. Freeze-dried strawberries absorbed 2-3 times more water than those dried by the ‘puffing’ effect.

scholarly journals The kinetics of the interaction of atomic hydrogen with olefines IV. Results obtained by the foregoing techniques

1949 ◽  
Vol 196 (1047) ◽  
pp. 494-509 ◽  
Keyword(s):  
Double Bond ◽  
Hydrogen Atom ◽  
Atomic Hydrogen ◽  
Experimental Techniques ◽  
Effective Diameter ◽  
Collision Efficiency ◽  
Ethylene Propylene ◽  
Theoretical Considerations ◽  
Kinetics Of ◽  
Effect Of Structure

The experimental techniques and theoretical considerations developed in the previous parts have been utilized in obtaining data on the reactions of the type H + C n H 2 n = C n H 2 n +1 . The olefines used were ethylene, propylene, iso -butene, n -pentene-2 ( cis ), and 2, 3, 3, tri-methyl-butene-1. Certain tentative suggestions as to the effect of structure on the reactivity of the double bond are put forward, but in general, the collision efficiency of a hydrogen atom with an olefine lies between 10 –3 and 10 –4 . It is noted that in the computation of the collision efficiency, it seems to be rather unsatisfactory that the diameter of the whole molecule should be used and it is suggested that perhaps the effective diameter of a more intimate part of the molecule in the region of the double bond should be employed.

Sign in / Sign up

Export Citation Format

Share Document