Diffusional Behavior of Tripaimitin in a Freeze‐Dried Model System at Different Water Activities

Naesens, W.; Bresseleers, G.; Tobback, Paul

doi:10.1111/j.1365-2621.1982.tb07657.x

Cited by 10 publications

(3 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Equilibration was performed during 48 h at room temperature, essentially according to the procedure described previously. 22 In most experiments, a relative humidity of 43% (u,,. = 0.43) was used.…”

Section: Equilibration Of Controlled Water Content Of the Enzyme Phasementioning

confidence: 99%

Lipase‐catalyzed ester exchange reactions in organic media with controlled humidity

Goderis

Ampe

Feyten

et al. 1987

Biotech & Bioengineering

184

View full text Add to dashboard Cite

Immobilized lipase activity is studied in organic solvent systems of controlled water content under the influence of a variety of reaction parameters, such as temperature, relative humidity, substrate concentrations, and type of fatty acid used. Control of the amount of water in the reaction system was found to be a valuable tool for the orientation of the reaction process and for the determination of the final reaction products. The properties of the immobilized lipase were studied using the interesterification of triolein and palmitic acid as the model system.

show abstract

Section: Equilibration Of Controlled Water Content Of the Enzyme Phasementioning

confidence: 99%

Lipase‐catalyzed ester exchange reactions in organic media with controlled humidity

Goderis

Ampe

Feyten

et al. 1987

Biotech & Bioengineering

184

View full text Add to dashboard Cite

show abstract

“…Further, they noted that extension of the analysis permits evaluation of the effect of skin on mass transport behaviour. Naesens, Bresseleers & Tobback (1982) investigated the effect of water activity on the spatial distribution of tripalmatin following diffusion into a food model system. They showed that tripalmatin was more rapidly transported, the higher the sample water activity.…”

Section: Introductionmentioning

confidence: 99%

Osmotic concentration of potato.

Lenart¹,

Flink²

1984

Int J of Food Sci Tech

108

View full text Add to dashboard Cite

The spatial distribution of solids and moisture depends on a number of factors, such as solute type, solution concentration, osmosis time, osmosis temperature and solution agitation. The spatial distribution was characterized by two terms: (i) the depth of penetration of the osmosis effect (e.g. depth to which solids concentration is higher than that found in the original tissue), and (ii) the moisture content of the surface relative to the initial moisture content. It was shown that to obtain usable distribution information, shrinkage of the sample which is occurring in the osmosis process must be considered in the calculations.Osmosis distribution curves were very different for osmosis in sucrose or in salt solutions. A model based on the development of a compacted surface tissue layer and on the presence of a liquid surface film for non-agitated systems is used to explain observed behaviour for osmosis in concentrated sucrose solutions. Osmosis in salt solutions is shown to follow a much different model, in which a significant salt transport occurs. Sucrose/salt mixtures show behaviour characteristics typical for osmosis in each of the pure solutes.On the basis of these models, the improved osmosis behaviour and improved product quality reported in the literature for products osmosed in mixed sucrose-salt solutions having sucrose concentrations above 40% is discussed.

show abstract

“…One good way of controlling the water activity is to adjust the water amount in the enzyme preparation and to keep the other components as dry as possible. A simple method of obtaining different water levels is equilibration of the immobilized enzyme over saturated salt solutions, which gives a defined water activity (19,20).…”

mentioning

confidence: 99%

Synthesis of monoglycerides by glycerolysis of rapeseed oil using immobilized lipase

Elfman‐Börjesson

Härröd

1999

J Americ Oil Chem Soc

View full text Add to dashboard Cite

Reaction conditions for the synthesis of monoglycerides (MG) by enzyme-catalyzed glycerolysis of rapeseed oil using Lipozyme ® IM have been studied. Silica gel was used to adsorb the glycerol to overcome the problems of low glycerol solubility in the organic phase. An experimental design was used where temperature, time, the ratio of silica gel to glycerol (w/w), the water activity (a w ), the isooctane concentration, and the ratio of glycerol to triglycerides (mol/mol) were varied. Response surface methodology was used to evaluate initial reaction rate and yield for the different products. The best yield of MG achieved under the studied conditions was 17.4% (mol fatty acid in substance/total mol fatty acid in mixture) (75°C, 20 h, silica gel/glycerol 2:1, a w = 0.17, 48% isooctane, glycerol/ triglycerides 6:1). The same conditions yielded 36.8% diglycerides, 13.6% free fatty acids (FFA), and 36.9% triglycerides. This is at the same level as the equilibrium yield. The yield of MG is low compared to the final yield achieved with solidphase glycerolysis. However, in solid-phase glycerolysis the reaction mixture becomes solid, and therefore the solid-phase process is not suitable for industrial application. The formation of FFA was very fast compared to the synthesis of MG. Equilibrium for FFA was reached within 2 h, and the yield was strongly affected by the a w . Increasing a w greatly increased the formation of FFA. In the a w ratio 0.06-0.3, the yield of FFA increased from 4 to 19% while the yield of MG was nearly unaffected. As FFA is an undesired product, it is important to keep the a w as low as possible.Paper no. J8908 in JAOCS 76, 701-707 (June 1999).

show abstract

Diffusional Behavior of Tripaimitin in a Freeze‐Dried Model System at Different Water Activities

Cited by 10 publications

References 15 publications

Lipase‐catalyzed ester exchange reactions in organic media with controlled humidity

Lipase‐catalyzed ester exchange reactions in organic media with controlled humidity

Osmotic concentration of potato.

Synthesis of monoglycerides by glycerolysis of rapeseed oil using immobilized lipase

Contact Info

Product

Resources

About