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Shaojin Wang - One of the best experts on this subject based on the ideXlab platform.
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Effects of combined radio frequency with hot water blanching on Enzyme Inactivation, color and texture of sweet potato
Innovative Food Science & Emerging Technologies, 2020Co-Authors: Jiang Hongyi, Bo Ling, Xu Zhou, Shaojin WangAbstract:Abstract Sweet potato is an important food crop with rich nutritional value, and also a commonly used feed and industrial raw material. However, the quality of sweet potatoes may decline during storage and thermal processes because of enzymatic reaction induced by peroxidase (POD). Radio frequency (RF) blanching was thus proposed to reduce POD activities. Effects of electrode gaps and sample thicknesses on the RF heating rate and uniformity in sweet potato were studied. Influences of hot water blanching and combination of RF heating with hot water blanching on Enzyme Inactivation and physiochemical properties of sweet potatoes were also analyzed. Results showed that the optimum RF heating uniformity was obtained at an electrode gap of 90 mm and a sample thickness of 60 mm. Combined RF with hot water blanching effectively inactivated POD in sweet potatoes. Compared to hot water blanching, combined RF with hot water blanching gave better sample color, texture values, and lower weight loss when achieving the same level of Enzyme Inactivation (
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Effects of hot air-assisted radio frequency heating on Enzyme Inactivation, lipid stability and product quality of rice bran
LWT, 2018Co-Authors: Bo Ling, James G. Lyng, Shaojin WangAbstract:Abstract Rice bran (RB) is a valuable by-product of rice milling but highly susceptible to lipid rancidity induced by inherent lipase (LA) and lipoxygenase (LOX) activities. Therefore a stabilization step is required to reduce activities of these Enzymes to ensure RB quality. Effects of hot air-assisted radio frequency (HAARF) heating on Enzyme Inactivation, lipid stability and product quality of RB were investigated. Influence of water activity (aw) in stabilized RB on lipid rancidity during storage was also evaluated. Results showed that average residual LA and LOX activities in RB treated by RF heating at electrode gap of 10 cm and to 100 °C with holding in hot air for 15min decreased to 19.2% and 5.5% of their original values. Free fatty acid content and peroxide value of RB oil extracted samples treated under these conditions remained below acceptable limits even following 60d storage at 35 °C. The lowest reaction rate for RB rancidity during storage occurred at aw value of 0.241. No significant adverse quality changes in RB were observed immediately following HAARF heating, and subsequent storage stability of RB was also enhanced by HAARF heating. HAARF heating can potentially provide rapid and effective methods for RB stabilization without adverse impact on product quality.
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thermal treatment and storage condition effects on walnut paste quality associated with Enzyme Inactivation
Lwt - Food Science and Technology, 2014Co-Authors: Bo Ling, Shaojin Wang, Lixia HouAbstract:Abstract In this study, walnut paste was heated at 60, 75, and 90 °C with three selected times for Enzyme Inactivation, and its quality stability was determined under accelerated storage conditions by evaluating peroxide value (PV), conjugated diene value (CDV), fatty acid value (FFA) and fatty acid composition. The results showed that the mean PV, CDV and FFA values of the heated paste samples increased with increasing treatment temperature and time. The PV and CDV were reduced or stable, while the FFA values increased significantly during storage period. However, no significant quality difference was observed between controls and heated walnut paste samples with vacuum package after accelerated storage for 20 days. Compared with unheated walnut kernels and cold-pressed oils in vacuum or normal package under same storage conditions, the mean PV of the unheated paste were the lowest, while its mean FFA values were the highest. FFA values of the paste were still lower than the acceptable range (FFA
Ken Houben - One of the best experts on this subject based on the ideXlab platform.
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Thermal and High-Pressure Stability of Pectinmethylesterase, Polygalacturonase, β-Galactosidase and α-Arabinofuranosidase in a Tomato Matrix: Towards the Creation of Specific Endogenous Enzyme Populations Through Processing
Food and Bioprocess Technology, 2013Co-Authors: Ken Houben, Sandy Van Buggenhout, Ruben P. Jolie, Ann Van Loey, Zahra Jamsazzadeh Kermani, Marc E. HendrickxAbstract:The thermal and pressure stability of tomato pectinmethylesterase (PME), polygalacturonase (PG), β-galactosidase (β-Gal), and α-arabinofuranosidase (α-Af) were investigated in situ. Enzyme Inactivation by thermal and high-pressure processing (respectively 5 min at 25–95 °C at 0.1 MPa and 10 min at 0.1–800 MPa at 20 °C) was monitored by measuring the residual activity in crude Enzyme extracts of treated tomato purée samples. PME was completely inactivated after a 5-min treatment at 75 °C. Only 30 % of the pressure stable PME was inactivated after a treatment at 800 MPa (20 °C, 10 min). A 5-min treatment at 95 °C and a treatment at 550 MPa (20 °C, 10 min) caused complete PG Inactivation. β-Gal and α-Af activities were already reduced significantly by thermal treatments at 42.5–52.5 °C and 45–60 °C, respectively. These Enzymes were, however, rather pressure resistant: treatments at respectively 700 and 600 MPa were necessary to reduce the activity below 10 % of the initial value. Assuming that first-order, fractional conversion or biphasic Inactivation models could be applied to the respective Enzyme Inactivation data, Inactivation rate constants and their temperature or pressure dependence for the different Enzymes were determined. Based on differences in process stability of the Enzymes, possibilities for the creation of specific “Enzyme populations” in tomato purée by selective Enzyme Inactivation were identified. For industrially relevant process conditions, the Enzyme Inactivation data obtained for tomato purée were shown to be transferable to intact tomato tissue.
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Thermal and High-Pressure Stability of Pectinmethylesterase, Polygalacturonase, β-Galactosidase and α-Arabinofuranosidase in a Tomato Matrix: Towards the Creation of Specific Endogenous Enzyme Populations Through Processing
Food and Bioprocess Technology, 2012Co-Authors: Ken Houben, Zahra Jamsazzadeh Kermani, Sandy Van Buggenhout, Ruben P. Jolie, Ann Van Loey, Marc HendrickxAbstract:The thermal and pressure stability of tomato pectinmethylesterase (PME), polygalacturonase (PG), β-galactosidase (β-Gal), and α-arabinofuranosidase (α-Af) were investigated in situ. Enzyme Inactivation by thermal and high-pressure processing (respectively 5 min at 25–95 °C at 0.1 MPa and 10 min at 0.1–800 MPa at 20 °C) was monitored by measuring the residual activity in crude Enzyme extracts of treated tomato puree samples. PME was completely inactivated after a 5-min treatment at 75 °C. Only 30 % of the pressure stable PME was inactivated after a treatment at 800 MPa (20 °C, 10 min). A 5-min treatment at 95 °C and a treatment at 550 MPa (20 °C, 10 min) caused complete PG Inactivation. β-Gal and α-Af activities were already reduced significantly by thermal treatments at 42.5–52.5 °C and 45–60 °C, respectively. These Enzymes were, however, rather pressure resistant: treatments at respectively 700 and 600 MPa were necessary to reduce the activity below 10 % of the initial value. Assuming that first-order, fractional conversion or biphasic Inactivation models could be applied to the respective Enzyme Inactivation data, Inactivation rate constants and their temperature or pressure dependence for the different Enzymes were determined. Based on differences in process stability of the Enzymes, possibilities for the creation of specific “Enzyme populations” in tomato puree by selective Enzyme Inactivation were identified. For industrially relevant process conditions, the Enzyme Inactivation data obtained for tomato puree were shown to be transferable to intact tomato tissue.
Antonio Delgado - One of the best experts on this subject based on the ideXlab platform.
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Uniformity of Enzyme Inactivation in a short-time high-pressure process
Journal of Food Engineering, 2009Co-Authors: Cornelia Rauh, A. Baars, Antonio DelgadoAbstract:This contribution investigates the impact of different thermal boundary and initial conditions on the homogeneity of Enzyme Inactivation during a short-time high-pressure (STHP) process (pressure ramp 400 MPa/s; holding time 120 s; pressure 700 MPa). Enzymes with different pressure- and temperature-sensitivity (β-glucanase, α-amylase, lipoxygenase, polyphenoloxidase) are chosen to examine the extent of the impact of thermofluiddynamical inhomogeneities on the final process result. Water serves as the process medium. Velocity, temperature and Enzyme activity fields in the treatment chamber are determined by numerical simulation. Depending on the parameter constellation, remarkable inhomogeneities in Enzyme concentration develop during the process. By characteristic time scales with consideration of boundary and initial conditions, thermal and conversion uniformity of the process can be estimated.
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The influence of transport phenomena during high-pressure processing of packed food on the uniformity of Enzyme Inactivation.
Biotechnology and bioengineering, 2003Co-Authors: Chr. Hartmann, Antonio DelgadoAbstract:Here we deal with the influence of heat-transport effects on a high-pressure-induced Enzyme Inactivation in packed substances. Special attention is given to the influence of the geometrical scale and to the heat-transfer characteristics of the packaging material. The investigation is based on mathematical modeling and numerical simulation. The method accounts both for compression phase and holding phase. The model includes convective and conductive heat transfer, fluid motion as well as an Enzyme transport equation with a first-order kinetic source term accounting for the Inactivation. Three configurations with a total volume of 0.8 L, 6.3 L, and 50.3 L are considered. The pressure medium is water. The Enzyme solution is B. subtilis α-amylase dissolved in a TRIS-HCl-buffer. The packaging material is polypropylene. The heat-transfer coefficient for conduction through the packaging material is varied to simulate both changes in the material properties as well as modifications of the packaging material thickness. It is found that the efficiency of the Inactivation increases with increasing chamber volume as long as the kinetic Inactivation constant is increasing with temperature. In the considered case the activity retention obtained in a 0.8 L volume is about 2.4 times larger than the one obtained for the same process carried out in a 50.3 L volume. Furthermore, it was found that the properties of the packaging material could induce a significant degree of nonuniformity (worst case = 69%). An appropriate choice of the material can lead to maximum Inactivation and maximum process uniformity since advantage is taken from the slow heat exchange after the compression phase. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 725–735, 2003.
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Numerical simulation of thermofluidynamics and Enzyme Inactivation in a fluid food system under high hydrostatic pressure
Progress in Biotechnology, 2002Co-Authors: Chr. Hartmann, Antonio DelgadoAbstract:In the present contribution a high hydrostatic pressure (HHP) treatment of a fluid food system is analysed by means of numerical simulation. The considered process is subdivided into a phase of pressure increase from ambient pressure to 500 MPa and a phase of constant pressure application. For both phases temperature and fluid velocity distributions are studied. In addition, results on the simulation of an Enzyme Inactivation are shown where the Inactivation is described by a model equation which is coupled with the equations of fluid dynamics. It can be shown that the Inactivation is heterogeneous when the viscosity of the matrix fluid is sufficiently high.
Marc Hendrickx - One of the best experts on this subject based on the ideXlab platform.
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Thermal and High-Pressure Stability of Pectinmethylesterase, Polygalacturonase, β-Galactosidase and α-Arabinofuranosidase in a Tomato Matrix: Towards the Creation of Specific Endogenous Enzyme Populations Through Processing
Food and Bioprocess Technology, 2012Co-Authors: Ken Houben, Zahra Jamsazzadeh Kermani, Sandy Van Buggenhout, Ruben P. Jolie, Ann Van Loey, Marc HendrickxAbstract:The thermal and pressure stability of tomato pectinmethylesterase (PME), polygalacturonase (PG), β-galactosidase (β-Gal), and α-arabinofuranosidase (α-Af) were investigated in situ. Enzyme Inactivation by thermal and high-pressure processing (respectively 5 min at 25–95 °C at 0.1 MPa and 10 min at 0.1–800 MPa at 20 °C) was monitored by measuring the residual activity in crude Enzyme extracts of treated tomato puree samples. PME was completely inactivated after a 5-min treatment at 75 °C. Only 30 % of the pressure stable PME was inactivated after a treatment at 800 MPa (20 °C, 10 min). A 5-min treatment at 95 °C and a treatment at 550 MPa (20 °C, 10 min) caused complete PG Inactivation. β-Gal and α-Af activities were already reduced significantly by thermal treatments at 42.5–52.5 °C and 45–60 °C, respectively. These Enzymes were, however, rather pressure resistant: treatments at respectively 700 and 600 MPa were necessary to reduce the activity below 10 % of the initial value. Assuming that first-order, fractional conversion or biphasic Inactivation models could be applied to the respective Enzyme Inactivation data, Inactivation rate constants and their temperature or pressure dependence for the different Enzymes were determined. Based on differences in process stability of the Enzymes, possibilities for the creation of specific “Enzyme populations” in tomato puree by selective Enzyme Inactivation were identified. For industrially relevant process conditions, the Enzyme Inactivation data obtained for tomato puree were shown to be transferable to intact tomato tissue.
Marc E. Hendrickx - One of the best experts on this subject based on the ideXlab platform.
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Thermal and High-Pressure Stability of Pectinmethylesterase, Polygalacturonase, β-Galactosidase and α-Arabinofuranosidase in a Tomato Matrix: Towards the Creation of Specific Endogenous Enzyme Populations Through Processing
Food and Bioprocess Technology, 2013Co-Authors: Ken Houben, Sandy Van Buggenhout, Ruben P. Jolie, Ann Van Loey, Zahra Jamsazzadeh Kermani, Marc E. HendrickxAbstract:The thermal and pressure stability of tomato pectinmethylesterase (PME), polygalacturonase (PG), β-galactosidase (β-Gal), and α-arabinofuranosidase (α-Af) were investigated in situ. Enzyme Inactivation by thermal and high-pressure processing (respectively 5 min at 25–95 °C at 0.1 MPa and 10 min at 0.1–800 MPa at 20 °C) was monitored by measuring the residual activity in crude Enzyme extracts of treated tomato purée samples. PME was completely inactivated after a 5-min treatment at 75 °C. Only 30 % of the pressure stable PME was inactivated after a treatment at 800 MPa (20 °C, 10 min). A 5-min treatment at 95 °C and a treatment at 550 MPa (20 °C, 10 min) caused complete PG Inactivation. β-Gal and α-Af activities were already reduced significantly by thermal treatments at 42.5–52.5 °C and 45–60 °C, respectively. These Enzymes were, however, rather pressure resistant: treatments at respectively 700 and 600 MPa were necessary to reduce the activity below 10 % of the initial value. Assuming that first-order, fractional conversion or biphasic Inactivation models could be applied to the respective Enzyme Inactivation data, Inactivation rate constants and their temperature or pressure dependence for the different Enzymes were determined. Based on differences in process stability of the Enzymes, possibilities for the creation of specific “Enzyme populations” in tomato purée by selective Enzyme Inactivation were identified. For industrially relevant process conditions, the Enzyme Inactivation data obtained for tomato purée were shown to be transferable to intact tomato tissue.