2026-05-12T02:17:27Zhttps://riubu.ubu.es/oai/requestoai:riubu.ubu.es:10259/50812022-04-20T12:29:24Zcom_10259_4244com_10259_5086com_10259_2604col_10259_4569
Benito Román, Oscar
59
500
0000-0002-4418-0045
Sanz Díez, Mª Teresa
530
500
Illera Gigante, Alba Ester
296
500
Melgosa Gómez, Rodrigo
357
500
Beltrán Calvo, Sagrario
57
500
2019-03-20T12:46:10Z
2019-03-20T12:46:10Z
2018
http://hdl.handle.net/10259/5081
Trabajo presentado en: 6th International Congress on Green Process Engineering (GPE 2018), 3 a 6 de junio de 2018, Toulouse
HPCD is a promising technology to inactivate the enzymes responsible for the juice spoilage, such as PPO and PME. In
order to understand the mechanism that induces this inactivation, a study using two commercial enzymes (PPO from
mushroom and PME from Aspergillus niger) was carried out. The effect of pressure, temperature, exposure time and ratio
CO2/enzyme ratio loaded in the reactor were studied. The experimental results (residual activity) were fitted to a kinetic
model that served to develop a complete kinetic study: the kinetic constants, activation volume and activation energy were
calculated, as well as the pressure and temperature sensitivity parameters (ZP and ZT, respectively). The changes in the
tertiary structure of the enzymes after different treatments were analyzed by fluorescence spectroscopy running different
tests: intrinsic fluorescence measurement, KI quenching and ANS binding experiments.
In the case of PPO, the experimental results revealed that this enzyme inactivation kinetics fitted the two fraction model,
which indicates the presence of labile and stable isoenzymes. Exposure time (2 to 15 minutes), temperature (25 to 45°C)
and pressure (50 to 200bar) were the studied experimental conditions that led to different physical states for the CO2 (gas,
liquid and supercritical). Despite the different experimental combinations of pressure and temperature tried, a similar
inactivation pattern was observed: a sudden decrease in activity (more than 75% of the total activity loss was observed
within the first 2 minutes) was followed by a slowed decay. At constant temperature, higher inactivation rates were observed
the higher the pressure, obtaining an almost complete inactivation at 200bar after 5 minutes regardless the temperature.
When temperature was increased, much faster inactivation rates were observed. ZP and ZT were in the range 69-78bar and
27-40°C, respectively.
In the case of the commercial PME, the use of supercritical CO2 (pressure 60-180bar, temperature 40-55°C and times up to
75 minutes) increased dramatically the PME inactivation rate, showing that pressure had a limited effect on PME inactivation
but temperature had an important effect. The pressure and temperature sensitivity parameters (ZP and ZT) confirmed that
trend, being in the range from 276 to 450bar and 8.7°C, respectively. The experimental data fitted the first order model and
the inactivation kinetics study of PME was completed with the calculations of the activation energy and volume of activation.
The ratio CO2/volume of enzyme (g/mL) loaded in the reactor was found to be critical for both enzymes. It was seen that
ratios higher than 3 did not improve the inactivation kinetics, being a waste of CO2 from the economic point of view. Bellow
that critical value, the inactivation of the enzyme strongly depended on pressure and temperature. In both cases the
structure of the enzyme was dramatically affected after exposure to HPCD, as revealed by the fluorescence spectroscopy
analysis that showed significant changes in the tertiary structure of the enzyme, which were compatible with the losses in
activity observed.
Spanish Governme nt (MINECO) and the European Regional Development Fund (ERDF) for financial support of
project CTQ2015-64396-R and A.E. Illera’s contract. To Junta de Castilla y León and ERDF for financial support of project
BU055U16 and O.Benito-Román’s Post-doctoral contract
application/pdf
eng
PPO
PME
juice
Supercritical Carbon Dioxide
green process
food technology
Ingeniería química
Chemical engineering
Polyphenol Oxidase (PPO) and Pectin Meth ylesterase (PME) inactivation by means of High Pressure Carbon Dioxide (HPCD)
info:eu-repo/semantics/conferenceObject
info:eu-repo/semantics/openAccess
THUMBNAIL
Polyphenol_oxidase _(ppo).pdf.jpg
Polyphenol_oxidase _(ppo).pdf.jpg
IM Thumbnail
image/jpeg
3811
https://riubu.ubu.es/bitstream/10259/5081/4/Polyphenol_oxidase%20_%28ppo%29.pdf.jpg
08f8eb4741c842c98b54162ecad61103
MD5
4
ORIGINAL
Polyphenol_oxidase _(ppo).pdf
Polyphenol_oxidase _(ppo).pdf
application/pdf
161578
https://riubu.ubu.es/bitstream/10259/5081/1/Polyphenol_oxidase%20_%28ppo%29.pdf
a2d385e0c4c6840daf8117dc3cd8e363
MD5
1
LICENSE
license.txt
license.txt
text/plain; charset=utf-8
999
https://riubu.ubu.es/bitstream/10259/5081/2/license.txt
b295bcbce42e2caabeb0c623d3860c06
MD5
2
TEXT
Polyphenol_oxidase _(ppo).pdf.txt
Polyphenol_oxidase _(ppo).pdf.txt
Extracted text
text/plain
15837
https://riubu.ubu.es/bitstream/10259/5081/3/Polyphenol_oxidase%20_%28ppo%29.pdf.txt
6acac4063f7b7ff7c451a071cc56d70f
MD5
3
10259/5081
oai:riubu.ubu.es:10259/5081
2022-04-20 14:29:24.486
Repositorio Institucional de la Universidad de Burgos
bubrep@ubu.es
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