Increased Inactivation of Exopolysaccharide-Producing Pediococcus parvulus in Apple Juice by Combined Treatment with Enterocin AS-48 and High-Intensity Pulsed Electric Field

2010 ◽  
Vol 73 (1) ◽  
pp. 39-43 ◽  
Author(s):  
PILAR MARTÍNEZ VIEDMA ◽  
ANGEL SOBRINO LÓPEZ ◽  
NABIL BEN OMAR ◽  
HIKMATE ABRIOUEL ◽  
ROSARIO LUCAS LÓPEZ ◽  
...  
Keyword(s):  
Electric Field ◽  
High Intensity ◽  
Apple Juice ◽  
Cyclic Peptide ◽  
Treatment Time ◽  
Combined Treatment ◽  
Storage Period ◽  
Pulsed Electric Field ◽  
Bipolar Mode ◽  
The Stability

The cyclic peptide bacteriocin enterocin AS-48 was tested (at final concentrations of 0.175, 0.613, and 1.05 AU/ml) against the exopolysaccharide-producing cider spoilage strain Pediococcus parvulus 48 in apple juice in combination with high-intensity pulsed electric field (HIPEF) treatment (35 kV/cm and 150 Hz for 4 μs and bipolar mode). The effect of the combined treatments was studied by surface response methodology, with AS-48 concentration and HIPEF treatment time as process variables. A bacteriocin concentration of 0.613 AU/ml in combination with HIPEF treatment time of 1,000 μs reduced the population of pediococci by 6.6 log cycles in apple juice and yielded an apple juice that was free from pediococci during a 30-day storage period at 4 and 22°C. In contrast, application of HIPEF treatment alone had no effect on the surviving pediococci during storage of juice at 22°C. The combined treatment significantly improved the stability of the juice against spoilage by exopolysaccharide-producing P. parvulus.

scholarly journals Quality stability and sensory attributes of apple juice processed by thermosonication, pulsed electric field and thermal processing

2016 ◽  
Vol 23 (3) ◽  
pp. 265-276 ◽  
Author(s):  
Alifdalino Sulaiman ◽  
Mohammed Farid ◽  
Filipa VM Silva
Keyword(s):  
Antioxidant Activity ◽  
Electric Field ◽  
Sensory Analysis ◽  
Thermal Processing ◽  
Apple Juice ◽  
Treatment Time ◽  
Pulsed Electric Field ◽  
Color Difference ◽  
Soluble Solids ◽  
Total Color Difference

Worldwide, apple juice is the second most popular juice, after orange juice. It is susceptible to enzymatic browning spoilage by polyphenoloxidase, an endogenous enzyme. In this study, Royal Gala apple juice was treated by thermosonication (TS: 1.3 W/mL, 58 ℃, 10 min), pulsed electric field (PEF: 24.8 kV/cm, 60 pulses, 169 µs treatment time, 53.8 ℃) and heat (75 ℃, 20 min) and stored at 3.0 ℃ and 20.0 ℃ for 30 days. A sensory analysis was carried out after processing. The polyphenoloxidase activity, antioxidant activity and total color difference of the apple juice were determined before and after processing and during storage. The sensory analysis revealed that thermosonication and pulsed electric field juices tasted differently from the thermally treated juice. Apart from the pulsed electric field apple juice stored at room temperature, the processed juice was stable during storage, since the pH and soluble solids remained constant and fermentation was not observed. Polyphenoloxidase did not reactivate during storage. Along storage, the juices’ antioxidant activity decreased and total color difference increased (up to 6.8). While the antioxidant activity increased from 86 to 103% with thermosonication and was retained after pulsed electric field, thermal processing reduced it to 67%. The processing increased the total color difference slightly. No differences in the total color difference of the juices processed by the three methods were registered after storage. Thermosonication and pulsed electric field could possibly be a better alternative to thermal preservation of apple juice, but refrigerated storage is recommended for pulsed electric field apple juice.

Effects of Pulsed Electric Field Processing on Apple and Pear Polyphenoloxidases

2001 ◽  
Vol 7 (4) ◽  
pp. 339-345 ◽  
Author(s):  
J. Giner ◽  
V. Gimeno ◽  
G. V. Barbosa-Cánovas ◽  
O. Martín
Keyword(s):  
Electric Field ◽  
Exponential Decay ◽  
Pulse Generator ◽  
Treatment Time ◽  
Electric Pulse ◽  
Pulsed Electric Field ◽  
Total Treatment Time ◽  
Bipolar Mode ◽  
Total Treatment ◽  
Exponential Decay Model

The feasibility of inhibiting polyphenoloxidase from apple and pear by pulsed electric field processing was evaluated. These treatments significantly lowered polyphenoloxidase activity of enzyme extracts from apple ( Golden deliciousvar.) and pear ( Blanquillavar.). Exponential decay pulses were generated by a laboratory scale electric pulse generator and applied in bipolar mode. Pulse duration was 0.02 ms and electric field intensities were up to 24.6 kV/cm. The temperature of samples never exceeded 15 ºC during pulsed electric field processing treatments. Polyphenoloxidase activities were reduced up to 3.15% and 38.0% initial value in apple extract at 24.6 kV/cm and pear extract at 22.3 kV/cm both for 6 ms total treatment time, respectively. Apple and pear polyphenoloxidase exposed to pulsed electric field processing diminishes their activities following first order kinetics. Rate constants ranged from 132 to 440 ms 1 for apple polyphenoloxidase, whereas for pear 1 and changed exponentially with the applied electric field intensity. Residual polyphenoloxidase activity was correlated to energy density by an exponential decay model.

Inactivation of Saccharomyces cerevisiae Suspended in Orange Juice Using High-Intensity Pulsed Electric Fields

2004 ◽  
Vol 67 (11) ◽  
pp. 2596-2602 ◽  
Author(s):  
PEDRO ELEZ-MARTÍNEZ ◽  
JOAN ESCOLÀ-HERNÁNDEZ ◽  
ROBERT C. SOLIVA-FORTUNY ◽  
OLGA MARTÍN-BELLOSO
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Orange Juice ◽  
High Intensity ◽  
Pulse Width ◽  
Treatment Time ◽  
Membrane Damage ◽  
Bipolar Mode

Saccharomyces cerevisiae is often associated with the spoilage of fruit juices. The purpose of this study was to evaluate the effect of high-intensity pulsed electric field (HIPEF) treatment on the survival of S. cerevisiae suspended in orange juice. Commercial heat-sterilized orange juice was inoculated with S. cerevisiae (CECT 1319) (108 CFU/ml) and then treated by HIPEFs. The effects of HIPEF parameters (electric field strength, treatment time, pulse polarity, frequency, and pulse width) were evaluated and compared to those of heat pasteurization (90°C/min). In all of the HIPEF experiments, the temperature was kept below 39°C. S. cerevisiae cell damage induced by HIPEF treatment was observed by electron microscopy. HIPEF treatment was effective for the inactivation of S. cerevisiae in orange juice at pasteurization levels. A maximum inactivation of a 5.1-log (CFU per milliliter) reduction was achieved after exposure of S. cerevisiae to HIPEFs for 1,000 μs (4-μs pulse width) at 35 kV/cm and 200 Hz in bipolar mode. Inactivation increased as both the field strength and treatment time increased. For the same electric field strength and treatment time, inactivation decreased when the frequency and pulse width were increased. Electric pulses applied in the bipolar mode were more effective than those in the monopolar mode for destroying S. cerevisiae. HIPEF processing inactivated S. cerevisiae in orange juice, and the extent of inactivation was similar to that obtained during thermal pasteurization. HIPEF treatments caused membrane damage and had a profound effect on the intra-cellular organization of S. cerevisiae.

Effect of enterocin AS-48 in combination with high-intensity pulsed-electric field treatment against the spoilage bacterium Lactobacillus diolivorans in apple juice

2009 ◽  
Vol 26 (5) ◽  
pp. 491-496 ◽  
Author(s):  
Pilar Martínez Viedma ◽  
Hikmate Abriouel ◽  
Angel Sobrino López ◽  
Nabil Ben Omar ◽  
Rosario Lucas López ◽  
...  
Keyword(s):  
Electric Field ◽  
High Intensity ◽  
Apple Juice ◽  
Pulsed Electric Field ◽  
Spoilage Bacterium ◽  
Pulsed Electric Field Treatment ◽  
Electric Field Treatment

Research Status of High-Intensity Pulsed Electric Field (PEF) Equipment and its Application on Food Processing

2014 ◽  
Vol 915-916 ◽  
pp. 331-335
Author(s):  
Rui Wen Yang ◽  
Jia Wang ◽  
Yan Jin ◽  
Song Yi Lin
Keyword(s):  
Electric Field ◽  
Food Processing ◽  
High Intensity ◽  
Treatment Time ◽  
Pulsed Electric Field ◽  
Short Treatment ◽  
Research Status ◽  
Chamber Pump ◽  
Cooling Coil ◽  
Short Treatment Time

Due to short treatment time, the quality change of food caused by heat can be reduced, high-intensity pulsed electric field (PEF) has been widely used, especially in food industry. PEF system consists of PEF generator, treatment chamber, pump, cooling coil, container and monitoring system. The research status of PEF generator, pulses waveforms, treatment chamber and electrodes were discussed. And the application of PEF on food processing was summarized.

scholarly journals Pulsed Electric Field (PEF) Enhances Iron Uptake by the Yeast Saccharomyces cerevisiae

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 850
Author(s):  
Karolina Nowosad ◽  
Monika Sujka ◽  
Urszula Pankiewicz ◽  
Damijan Miklavčič ◽  
Marta Arczewska
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Electric Field ◽  
Metal Ion ◽  
Treatment Time ◽  
Control Sample ◽  
Pulsed Electric Field ◽  
Yeast Cells ◽  
Iron Ions ◽  
Metal Ion Binding ◽  
Yeast Saccharomyces Cerevisiae

The aim of the study was to investigate the influence of a pulsed electric field (PEF) on the level of iron ion accumulation in Saccharomyces cerevisiae cells and to select PEF conditions optimal for the highest uptake of this element. Iron ions were accumulated most efficiently when their source was iron (III) nitrate. When the following conditions of PEF treatment were used: voltage 1500 V, pulse width 10 μs, treatment time 20 min, and a number of pulses 1200, accumulation of iron ions in the cells from a 20 h-culture reached a maximum value of 48.01 mg/g dry mass. Application of the optimal PEF conditions thus increased iron accumulation in cells by 157% as compared to the sample enriched with iron without PEF. The second derivative of the FTIR spectra of iron-loaded and -unloaded yeast cells allowed us to determine the functional groups which may be involved in metal ion binding. The exposure of cells to PEF treatment only slightly influenced the biomass and cell viability. However, iron-enriched yeast (both with or without PEF) showed lower fermentative activity than a control sample. Thus obtained yeast biomass containing a high amount of incorporated iron may serve as an alternative to pharmacological supplementation in the state of iron deficiency.

Inactivation of E. coli K12 in apple juice by high voltage pulsed electric field

2003 ◽  
Vol 217 (5) ◽  
pp. 434-437 ◽  
Author(s):  
B. Sen Gupta ◽  
F. Masterson ◽  
T. R. A. Magee
Keyword(s):  
Electric Field ◽  
High Voltage ◽  
Apple Juice ◽  
Pulsed Electric Field ◽  
E Coli
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