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Effect of high-pressure processing on colour, texture and flavour of fruit-and vegetable-based food products: a reviewmore
by Indrawati Oey and A. Van Loey
Colour, flavour and texture are important quality characteristics of fruits and vegetables and major factors affecting sensory perception and consumer acceptance of foods. Various processing methods are used not only to increase the... more
Colour, flavour and texture are important quality characteristics of fruits and vegetables and major factors affecting sensory perception and consumer acceptance of foods. Various processing methods are used not only to increase the edibility and palatability of fruits and ...
Publisher: Elsevier
Publication Date: 2008
Publication Name: Trends in food science & …
Research Interests:
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A crude plasmin extract was prepared from milk by ultracentrifugation and was partially purified using ammonium sulfate precipitation. Isothermal and high-pressure inactivation of this plasmin system at pH 6.7 could be described by a... more
A crude plasmin extract was prepared from milk by ultracentrifugation and was partially purified using ammonium sulfate precipitation. Isothermal and high-pressure inactivation of this plasmin system at pH 6.7 could be described by a first-order kinetic model. As expected, the plasmin system displayed a high thermostability. High-pressure treatments were conducted in the 300- to 800-MPa pressure range, combined with temperatures from 25 to 65 degrees C. The plasmin system was very pressure stable at room temperature, but inactivation occurred with combined high-pressure/temperature-treatments. The influence of temperature at different constant pressures on the inactivation rate constant was quantified using the Arrhenius equation. At all temperatures studied, a synergistic effect of temperature and high pressure was observed in the 300- to 600-MPa pressure range. However, an antagonistic effect of temperature and pressure appeared at pressures above 600 MPa.
Publication Name: Journal of Dairy Science
Research Interests: Thermodynamics, High Pressure, Dairy Science, Kinetics, Animal Production, and 14 moreAnimals, Temperature, First-Order Logic, Pi, Milk, Pressure, Room Temperature, Food Sciences, Lumping Kinetic Model, Hydrogen-Ion Concentration, Ammonium Sulfate, *Hot Temperature, Plasminogen Activator, and Synergistic effect
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Impact evaluation of high pressure treatment on foods: considerations on the development of pressure–temperature–time integrators (pTTIs)more
by Indrawati Oey and A. Van Loey
Publication Date: 2008
Publication Name: Trends in Food Science & Technology
Research Interests:
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by Indrawati Oey and A. Van Loey
Publication Date: 2008
Publication Name: Trends in Food Science & Technology
Research Interests:
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Thermal Stability of l-Ascorbic Acid and Ascorbic Acid Oxidase in Broccoli (Brassica oleracea var. italica)more
by Indrawati Oey and A. Van Loey
Publication Date: 2010
Publication Name: Journal of Food Science
Research Interests:
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Effects of pressure/temperature treatments on stability and activity of endogenous broccoli ( Brassica oleracea L. cv. Italica) myrosinase and on cell permeabilitymore
by Indrawati Oey and A. Van Loey
Broccoli contains glucosinolates, which can be hydrolysed by myrosinase (EC 3.2.1.147) after cell disruption, to yield a range of products, of which some have anticarcinogenic properties. Since thermal processing results in myrosinase... more
Broccoli contains glucosinolates, which can be hydrolysed by myrosinase (EC 3.2.1.147) after cell disruption, to yield a range of products, of which some have anticarcinogenic properties. Since thermal processing results in myrosinase inactivation, the use of a high pressure/temperature treatment (HP/T), which can induce cell permeabilisation at moderate conditions, can be an alternative. In this research it was investigated at
Publication Date: 2008
Publication Name: Journal of Food Engineering
Research Interests:
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Influence of Thermal Processing on Hydrolysis and Stability of Folate Poly-γ-glutamates in Broccoli ( Brassica oleracea var. italica ), Carrot ( Daucus carota ) and Tomato ( Lycopersicon esculentum )more
by Indrawati Oey and A. Van Loey
The folate poly-gamma-glutamate profile, their concentrations, and hydrolysis by endogenous gamma-glutamyl hydrolase (GGH) were evaluated in broccoli, carrot and tomato. Further studies on the effect of time and temperature on folate... more
The folate poly-gamma-glutamate profile, their concentrations, and hydrolysis by endogenous gamma-glutamyl hydrolase (GGH) were evaluated in broccoli, carrot and tomato. Further studies on the effect of time and temperature on folate poly-gamma-glutamate hydrolysis and stability were carried out in broccoli since this vegetable showed the highest long-chain and total folate poly-gamma-glutamate concentration. The evolution of l-ascorbic acid, total phenols and Trolox equivalent antioxidant capacity (TEAC) values was evaluated in parallel. Upon thermal inactivation of GGH prior to crushing, it was observed that broccoli, carrot and tomato contained poly-gamma-glutamates with one to seven glutamate residues but differed in the predominant poly-gamma-glutamates. Crushing of raw broccoli, carrot and tomato resulted in significant poly-gamma-glutamate profile changes in broccoli and carrot (indicating GGH-catalyzed hydrolysis) but not in tomato. In this study, the actual crushing of raw broccoli matrix had a greater effect on folate poly-gamma-glutamate hydrolysis than incubation conditions (0-30 min at 25-55 degrees C). During treatments at 25-140 degrees C, folate retention was higher at 80 and 100 degrees C than at the other temperatures. A similar trend in thermal stability was observed for folates, vitamin C, total phenols and TEAC value, an indication that conditions that result in endogenous antioxidants degradation might also result in folate degradation.
Publication Date: 2010
Publication Name: Journal of Agricultural and Food Chemistry
Research Interests: Engineering, Folic acid, Food Science and Technology, TIME, Antioxidants, and 16 moreGlutamate, Temperature, Tomato, Agricultural, CHEMICAL SCIENCES, Brassica oleracea, Brassica, Thermal Stability, Agricultural and Food Chemistry, Time, Food Handling & Hygiene, Hydrolysis, Thermal Processing, *Hot Temperature, Lycopersicon esculentum, and Daucus Carota
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Effects of Cryostabilizers, Low Temperature, and Freezing on the Kinetics of the Pectin Methylesterase-Catalyzed De-esterification of Pectinmore
by A. Van Loey
The kinetics of the pectin methylesterase (PME)-catalyzed de-esterification of pectin was studied at 25 degrees C in the presence of sucrose, fructose, maltodextrin (DE = 16.5-19.5), and carboxymethylcellulose at different concentrations... more
The kinetics of the pectin methylesterase (PME)-catalyzed de-esterification of pectin was studied at 25 degrees C in the presence of sucrose, fructose, maltodextrin (DE = 16.5-19.5), and carboxymethylcellulose at different concentrations and in the presence of maltodextrin and sucrose at different concentrations in a temperature range between +25 and -4 degrees C in subcooled and frozen states. The objective was to determine whether the reaction is diffusion-controlled, to gain insight about the factors determining the diffusion of the reactants, and to determine the effect of the carbohydrates, low temperature, and freezing on the structural conformation of the enzyme. The results indicate that the PME-catalyzed de-esterification of pectin is diffusion-controlled. Nevertheless, the diffusion is not controlled by the macroviscosity of the reaction medium, but rather by the microviscosity experienced by the diffusants. Low temperature in the temperature range studied does not affect the structural conformation of the enzyme, while freezing seems to have some effect.
Publication Date: 2005
Publication Name: Journal of Agricultural and Food Chemistry
Research Interests:
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Mechanism and Related Kinetics of 5-Methyltetrahydrofolic Acid Degradation during Combined High Hydrostatic Pressure−Thermal Treatmentsmore
by Indrawati Oey and A. Van Loey
Publication Date: 2009
Publication Name: Journal of Agricultural and Food Chemistry
Research Interests:
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Kinetics of the Stability of Broccoli ( Brassica oleracea Cv. Italica) Myrosinase and Isothiocyanates in Broccoli Juice during Pressure/Temperature Treatmentsmore
by Indrawati Oey and A. Van Loey
The Brassicaceae plant family contains high concentrations of glucosinolates, which can be hydrolyzed by myrosinase yielding products having an anticarcinogenic activity. The pressure and temperature stabilities of endogenous broccoli... more
The Brassicaceae plant family contains high concentrations of glucosinolates, which can be hydrolyzed by myrosinase yielding products having an anticarcinogenic activity. The pressure and temperature stabilities of endogenous broccoli myrosinase, as well as of the synthetic isothiocyanates sulforaphane and phenylethyl isothiocyanate, were studied in broccoli juice on a kinetic basis. At atmospheric pressure, kinetics of thermal (45-60 degrees C) myrosinase inactivation could be described by a consecutive step model. In contrast, only one phase of myrosinase inactivation was observed at elevated pressure (100-600 MPa) combined with temperatures from 10 up to 60 degrees C, indicating inactivation according to first-order kinetics. An antagonistic effect of pressure (up to 200 MPa) on thermal inactivation (50 degrees C and above) of myrosinase was observed indicating that pressure retarded the thermal inactivation. The kinetic parameters of myrosinase inactivation were described as inactivation rate constants (k values), activation energy (Ea values), and activation volume (Va values). On the basis of the kinetic data, a mathematical model describing the pressure and temperature dependence of myrosinase inactivation rate constants was constructed. The stability of isothiocyanates was studied at atmospheric pressure in the temperature range from 60 to 90 degrees C and at elevated pressures in the combined pressure-temperature range from 600 to 800 MPa and from 30 to 60 degrees C. It was found that isothiocyanates were relatively thermolabile and pressure stable. The kinetics of HP/T isothiocyanate degradation could be adequately described by a first-order kinetic model. The obtained kinetic information can be used for process evaluation and optimization to increase the health effect of Brassicaceae.
Publication Date: 2007
Publication Name: Journal of Agricultural and Food Chemistry
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Influence of Reducing Carbohydrates on (6S)-5-Methyltetrahydrofolic Acid Degradation during Thermal Treatmentsmore
by Indrawati Oey and A. Van Loey
Research Interests:
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Thermal pretreatments of carrot pieces using different heating techniques: Effect on quality related aspectsmore
by A. Van Loey
During fruit and vegetable processing, different thermal processes (blanching, pasteurization, sterilization) based on different heating techniques can be used. In this context, it is important to evaluate the impact of blanching on... more
During fruit and vegetable processing, different thermal processes (blanching, pasteurization, sterilization) based on different heating techniques can be used. In this context, it is important to evaluate the impact of blanching on quality related parameters.This paper describes a case study on carrot pieces, studying the effect of thermal pretreatments (high temperature blanching, low temperature blanching and low temperature blanching in
Publication Date: 2009
Publication Name: Innovative Food Science & Emerging Technologies
Research Interests:
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Towards a better understanding of the relationship between the β-carotene in vitro bio-accessibility and pectin structural changes: A case study on carrotsmore
by Indrawati Oey and A. Van Loey
The quality of fruit and vegetables based products is affected by processing. Two important parameters to consider are the structural characteristics and the nutritional value. As pectin is a major constituent of plant cell walls, pectin... more
The quality of fruit and vegetables based products is affected by processing. Two important parameters to consider are the structural characteristics and the nutritional value. As pectin is a major constituent of plant cell walls, pectin structure engineering can be used as a tool to affect the structural quality of plant based food products. During thermal processing, pectin characteristics are
Publication Date: 2009
Publication Name: Food Research International
Research Interests: Engineering, Chemical Engineering, Psychology, Cognitive Science, Developmental Psychology, and 21 moreCondensed Matter Physics, Structural Engineering, Child Development, Theory of Mind, Food, Physical Activity, Health, Linguistics, Executive Control, Executive Functioning, Environmental Sciences, Case Study, Structural Change, Fruit and vegetables, Developmental Science, Food Sciences, Nutritional Value, Plant Cell Wall, Food Products, Urban Landscape and Planning, and Thermal Processing
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High-pressure treatments induce folate polyglutamate profile changes in intact broccoli ( Brassica oleraceae L. cv. Italica) tissuemore
by Indrawati Oey and A. Van Loey
In plant matrices, folates exist largely as folylpoly-γ-glutamates requiring deglutamylation to monoglutamates prior to absorption, which might impair dietary folate bioavailability. This study investigated folylpoly-γ-glutamate stability... more
In plant matrices, folates exist largely as folylpoly-γ-glutamates requiring deglutamylation to monoglutamates prior to absorption, which might impair dietary folate bioavailability. This study investigated folylpoly-γ-glutamate stability and conversions in broccoli tissue during thermal (25–90°C, 30min) and high-pressure treatments (0.1–600MPa, 25–45°C, 30min) after vacuum packaging. Folates were analyzed based on poly-γ-glutamate side chain length by RP-HPLC. During thermal treatments, folates were
Publication Date: 2008
Publication Name: Food Chemistry
Research Interests:
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Influence of pressure/temperature treatments on glucosinolate conversion in broccoli (Brassica oleraceae L. cv Italica) headsmore
by Indrawati Oey and A. Van Loey
Glucosinolates are a group of secondary plant metabolites that are found in the Brassicaceae family. Upon hydrolysis by the endogenous enzyme myrosinase, a large number of compounds can be formed of which some are potentially... more
Glucosinolates are a group of secondary plant metabolites that are found in the Brassicaceae family. Upon hydrolysis by the endogenous enzyme myrosinase, a large number of compounds can be formed of which some are potentially anticarcinogenic, while others are largely ...
Publication Date: 2009
Publication Name: Food Chemistry
Research Interests:
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by Indrawati Oey and A. Van Loey
The degradation of anthocyanins (pelargonidin-3-glucoside) in a strawberry paste during high-temperature/high-pressure treatments was investigated over a temperature range of 80130 °C and a pressure range of 200700 MPa, compared to 0.1... more
The degradation of anthocyanins (pelargonidin-3-glucoside) in a strawberry paste during high-temperature/high-pressure treatments was investigated over a temperature range of 80130 °C and a pressure range of 200700 MPa, compared to 0.1 MPa. A first-order ...
Publication Date: 2010
Publication Name: Food Chemistry
Research Interests:
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Acidification, crushing and thermal treatments can influence the profile and stability of folate poly-γ-glutamates in broccoli ( Brassica oleracea L. var. italica)more
by Indrawati Oey and A. Van Loey
The influence of different treatments, i.e., crushing, high temperature short time (90°C/4min) (HTST) and low temperature long time (60°C/40min) (LTLT) blanching, acidification (pH 4.3), and sequences of these treatments on the folate... more
The influence of different treatments, i.e., crushing, high temperature short time (90°C/4min) (HTST) and low temperature long time (60°C/40min) (LTLT) blanching, acidification (pH 4.3), and sequences of these treatments on the folate poly-γ-glutamate profile and stability were investigated. In this study, broccoli was used as a case study. Regarding the folate poly-γ-glutamate profile, endogenous folate poly-γ-glutamates in broccoli florets were
Publication Date: 2009
Publication Name: Food Chemistry
Research Interests:
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Application of thermal inactivation of enzymes during vitamin C analysis to study the influence of acidification, crushing and blanching on vitamin C stability in Broccoli (Brassica oleracea L var. italica)more
by Indrawati Oey and A. Van Loey
The effectiveness of heat inactivation of oxidative enzymes e.g., ascorbic acid oxidase (AAO) to stabilise vitamin C during extraction and analysis was evaluated. The influence of different sequences of performing treatments including... more
The effectiveness of heat inactivation of oxidative enzymes e.g., ascorbic acid oxidase (AAO) to stabilise vitamin C during extraction and analysis was evaluated. The influence of different sequences of performing treatments including acidification (pH 4.3 vs. pH 6.5), crushing, high temperature short time (90°C/4min–HTST) and low temperature long time (60°C/40min–LTLT)) blanching on vitamin C stability in broccoli florets and stalks
Publication Date: 2010
Publication Name: Food Chemistry
Research Interests:
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Temperature and pressure stability of l-ascorbic acid and/or [6s] 5-methyltetrahydrofolic acid: A kinetic studymore
by Indrawati Oey and A. Van Loey
Publication Date: 2006
Publication Name: European Food Research and Technology
Research Interests:
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Publication Date: 2006
Publication Name: European Food Research and Technology
Research Interests:
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Behavior of mustard seed (Sinapis alba L.) myrosinase during temperature/pressure treatments: a case study on enzyme activity and stabilitymore
by Indrawati Oey and A. Van Loey
Publication Date: 2008
Publication Name: European Food Research and Technology
Research Interests:
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Publication Date: 2003
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CHARACTERIZATION AND INACTIVATION BY THERMAL AND PRESSURE PROCESSING OF STRAWBERRY (FRAGARIA ANANASSA) POLYPHENOL OXIDASE: A KINETIC STUDYmore
by Gabriela Rapeanu and A. Van Loey