The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Colm P Odonnell - One of the best experts on this subject based on the ideXlab platform.

  • effect of thermosonication on bioactive compounds in watermelon juice
    Food Research International, 2011
    Co-Authors: Ashish Rawso, Ijesh K Tiwari, Anki Patras, Nigel P Unto, Charles S Enna, P J Culle, Colm P Odonnell
    Abstract:

    Abstract Freshly squeezed watermelon juice was subjected to thermosonication treatments with processing variables of temperature (25–45 °C), Amplitude Level (24.1–60 μm) and processing time (2–10 min) at a constant frequency of 20 kHz and pulse durations of 5 s on and 5 s off. Hunter color values ( L* , a* and b* ), lycopene (LC), phenolic content (TP) and ascorbic acid (AA) content were measured. Higher retention of AA and LC was observed at low treatment conditions. AA, LC & TP decreased significantly at higher Amplitude Levels and at the maximum processing time. A second order response function covering the range of experimental conditions investigated was obtained for each of the compounds measured. Model predictions for color parameters and bioactive compounds were closely correlated to the experimental results obtained. Prediction models were found to be significant ( p 2 ). It was concluded that thermosonication significantly influences key watermelon juice quality parameters

  • effect of sonication on colour ascorbic acid and yeast inactivation in tomato juice
    Food Chemistry, 2010
    Co-Authors: A Adekunte, P. J. Cullen, Brijesh K Tiwari, Amalia G M Scannell, Colm P Odonnell
    Abstract:

    Power ultrasound is recognised as a potential non-thermal technique to inactivate micro-organisms pertinent to fruit juices. In this study tomato juice was sonicated at different Amplitude Levels (24.4–61.0 μm) at a constant frequency of 20 kHz for treatment times (2–10 min) and pulse durations of 5 s on and 5 s off. Hunter colour values (L*, a* and b*), pH, °Brix, titratable acidity, ascorbic acid and yeast inactivation were measured. No significant differences (p < 0.05) in pH, °Brix or titratable acidity were observed. Regression modelling was used to investigate the main effects of Amplitude Level and treatment time. Prediction models were found to be significant (p < 0.05) with low standard errors and high coefficients of determination (R2). Model predictions for critical quality parameters of Hunter colour values (L*, a* and b*), ascorbic acid and yeast inactivation were closely correlated with the experimental results obtained.

  • effect of ultrasound processing on anthocyanins and color of red grape juice
    Ultrasonics Sonochemistry, 2010
    Co-Authors: Brijesh K Tiwari, P. J. Cullen, Ankit Patras, Nigel P Brunton, Colm P Odonnell
    Abstract:

    Abstract Grape juice samples were sonicated with processing variables of Amplitude Level (24.4–61.0 μm) and treatment time (0–10 min) at a constant frequency of 20 kHz and pulse durations of 5 s on and 5 s off. A full factorial experimental design with regression modeling was employed to investigate the main effects of Amplitude Level and treatment time on anthocyanins and color parameters. Significant effects of sonication on major anthocyanins cyanidin-3-O-glucosides (CA), malvanidin-3-O-glucosides (MA) and delphinidin-3-O-glucosides (DA), color values ( L *, a *, b *) and color index (CI) were observed. Prediction models were found to be significant ( p R 2 ). Model predictions for critical quality parameters of anthocyanins (CA; MA; DA), color values ( L *, a *, b *), TCD and CI inactivation were closely correlated to the experimental results obtained. Significant retention of anthocyanin content in grape juice was observed for CA (97.5 %); MA (48.2 %) and DA (80.9%) during sonication. CI and other color combinations ( L * a * b *, L * a * /b * and L * b * /a *) were found to be strongly correlated with anthocyanin content. This study shows that sonication could be employed for as a preservation technique for fruit juice processing where anthocyanin retention is desired.

  • quantitative modelling approaches for ascorbic acid degradation and non enzymatic browning of orange juice during ultrasound processing
    Journal of Food Engineering, 2010
    Co-Authors: V P Valdramidis, P. J. Cullen, Brijesh K Tiwari, Colm P Odonnell
    Abstract:

    Abstract The objective of this study was to develop a deterministic modelling approach for non-enzymatic browning (NEB) and ascorbic acid (AA) degradation in orange juice during ultrasound processing. Freshly squeezed orange juice was sonicated using a 1500 W ultrasonic processor at a constant frequency of 20 kHz and processing variables of Amplitude Level (24.4–61.0 μm), temperature (5–30 °C) and time (0–10 min). The rate constants of the NEB and AA were estimated by a primary model (zero and first order) while their relationship with respect to the processing factors was tested for a number of models, i.e., second order polynomial, different types of Ratkowsky-type model, and an Arrhenius-type model. The non-monotonic behaviour of NEB has been described more accurately by the use of a polynomial model. The rate constants of AA were described by a similar type of model having a monotonic behaviour. A synergistic effect of temperature for different Amplitudes on the rate constant of both NEB and AA was observed, while an antagonistic effect of Amplitude on the rate of NEB was evident. The models with the best fit were integrated to produce contour plots for the combined Amplitude and temperature. The constructed contour plots illustrate that low temperatures and intermediate Amplitudes, i.e., 42.7 μm, result in lower NEB and AA deterioration and consequently better quality orange juice. The overall developed modelling approaches exploit quality data in order to identify the optimal processing regions for eliminating quality deterioration of orange juice during ultrasound processing which is of high importance to the food industry.

  • effect of sonication on retention of anthocyanins in blackberry juice
    Journal of Food Engineering, 2009
    Co-Authors: Brijesh K Tiwari, Colm P Odonnell, P. J. Cullen
    Abstract:

    Abstract Blackberry juice samples were sonicated with processing variables of Amplitude Levels ranging from 40% to 100% at a constant frequency of 20 kHz and sonication times (0–10 min) and pulse durations of 5 s on and 5 s off. The effects of sonication on anthocyanins (Cy3Gl) and colour values ( L , a , and b ) were determined. Response surface methodology (RSM) based on two factor five Level central composite design was applied to determine the effect of Amplitude Level and sonication time. A second-order polynomial model fitted well to the experimental data ( R 2  > 0.89). Significant retention of anthocyanin content (>94%) was observed at the maximum treatment conditions of 100% Amplitude Level for 10 min, indicating stability of anthocyanin during sonication. Colour changes observed during sonication were subtle (TCD ∼ 5%). RSM was demonstrated to be an effective technique to investigate the influence of sonication on colour and anthocyanin retention. Sonication could be employed as a preservation technique for blackberry juice processing where anthocyanin retention is desired.

P. J. Cullen - One of the best experts on this subject based on the ideXlab platform.

  • effect of sonication on colour ascorbic acid and yeast inactivation in tomato juice
    Food Chemistry, 2010
    Co-Authors: A Adekunte, P. J. Cullen, Brijesh K Tiwari, Amalia G M Scannell, Colm P Odonnell
    Abstract:

    Power ultrasound is recognised as a potential non-thermal technique to inactivate micro-organisms pertinent to fruit juices. In this study tomato juice was sonicated at different Amplitude Levels (24.4–61.0 μm) at a constant frequency of 20 kHz for treatment times (2–10 min) and pulse durations of 5 s on and 5 s off. Hunter colour values (L*, a* and b*), pH, °Brix, titratable acidity, ascorbic acid and yeast inactivation were measured. No significant differences (p < 0.05) in pH, °Brix or titratable acidity were observed. Regression modelling was used to investigate the main effects of Amplitude Level and treatment time. Prediction models were found to be significant (p < 0.05) with low standard errors and high coefficients of determination (R2). Model predictions for critical quality parameters of Hunter colour values (L*, a* and b*), ascorbic acid and yeast inactivation were closely correlated with the experimental results obtained.

  • effect of ultrasound processing on anthocyanins and color of red grape juice
    Ultrasonics Sonochemistry, 2010
    Co-Authors: Brijesh K Tiwari, P. J. Cullen, Ankit Patras, Nigel P Brunton, Colm P Odonnell
    Abstract:

    Abstract Grape juice samples were sonicated with processing variables of Amplitude Level (24.4–61.0 μm) and treatment time (0–10 min) at a constant frequency of 20 kHz and pulse durations of 5 s on and 5 s off. A full factorial experimental design with regression modeling was employed to investigate the main effects of Amplitude Level and treatment time on anthocyanins and color parameters. Significant effects of sonication on major anthocyanins cyanidin-3-O-glucosides (CA), malvanidin-3-O-glucosides (MA) and delphinidin-3-O-glucosides (DA), color values ( L *, a *, b *) and color index (CI) were observed. Prediction models were found to be significant ( p R 2 ). Model predictions for critical quality parameters of anthocyanins (CA; MA; DA), color values ( L *, a *, b *), TCD and CI inactivation were closely correlated to the experimental results obtained. Significant retention of anthocyanin content in grape juice was observed for CA (97.5 %); MA (48.2 %) and DA (80.9%) during sonication. CI and other color combinations ( L * a * b *, L * a * /b * and L * b * /a *) were found to be strongly correlated with anthocyanin content. This study shows that sonication could be employed for as a preservation technique for fruit juice processing where anthocyanin retention is desired.

  • quantitative modelling approaches for ascorbic acid degradation and non enzymatic browning of orange juice during ultrasound processing
    Journal of Food Engineering, 2010
    Co-Authors: V P Valdramidis, P. J. Cullen, Brijesh K Tiwari, Colm P Odonnell
    Abstract:

    Abstract The objective of this study was to develop a deterministic modelling approach for non-enzymatic browning (NEB) and ascorbic acid (AA) degradation in orange juice during ultrasound processing. Freshly squeezed orange juice was sonicated using a 1500 W ultrasonic processor at a constant frequency of 20 kHz and processing variables of Amplitude Level (24.4–61.0 μm), temperature (5–30 °C) and time (0–10 min). The rate constants of the NEB and AA were estimated by a primary model (zero and first order) while their relationship with respect to the processing factors was tested for a number of models, i.e., second order polynomial, different types of Ratkowsky-type model, and an Arrhenius-type model. The non-monotonic behaviour of NEB has been described more accurately by the use of a polynomial model. The rate constants of AA were described by a similar type of model having a monotonic behaviour. A synergistic effect of temperature for different Amplitudes on the rate constant of both NEB and AA was observed, while an antagonistic effect of Amplitude on the rate of NEB was evident. The models with the best fit were integrated to produce contour plots for the combined Amplitude and temperature. The constructed contour plots illustrate that low temperatures and intermediate Amplitudes, i.e., 42.7 μm, result in lower NEB and AA deterioration and consequently better quality orange juice. The overall developed modelling approaches exploit quality data in order to identify the optimal processing regions for eliminating quality deterioration of orange juice during ultrasound processing which is of high importance to the food industry.

  • effect of sonication on retention of anthocyanins in blackberry juice
    Journal of Food Engineering, 2009
    Co-Authors: Brijesh K Tiwari, Colm P Odonnell, P. J. Cullen
    Abstract:

    Abstract Blackberry juice samples were sonicated with processing variables of Amplitude Levels ranging from 40% to 100% at a constant frequency of 20 kHz and sonication times (0–10 min) and pulse durations of 5 s on and 5 s off. The effects of sonication on anthocyanins (Cy3Gl) and colour values ( L , a , and b ) were determined. Response surface methodology (RSM) based on two factor five Level central composite design was applied to determine the effect of Amplitude Level and sonication time. A second-order polynomial model fitted well to the experimental data ( R 2  > 0.89). Significant retention of anthocyanin content (>94%) was observed at the maximum treatment conditions of 100% Amplitude Level for 10 min, indicating stability of anthocyanin during sonication. Colour changes observed during sonication were subtle (TCD ∼ 5%). RSM was demonstrated to be an effective technique to investigate the influence of sonication on colour and anthocyanin retention. Sonication could be employed as a preservation technique for blackberry juice processing where anthocyanin retention is desired.

  • effect of sonication on orange juice quality parameters during storage
    International Journal of Food Science and Technology, 2009
    Co-Authors: Brijesh K Tiwari, Kasiviswanathan Muthukumarappan, C P O Donnell, P. J. Cullen
    Abstract:

    Summary Freshly squeezed orange juice was sonicated at various Amplitude Levels (40%, 70%, 100%), treatment times (2, 6 and 10 min) at a constant frequency of 20 kHz. Samples were stored for periods of up to 30 days at 10 °C. The combined effect of Amplitude Level, treatment time and storage period on pH, oBrix, titratable acidity, colour values (L*, a*, b*), non-enzymatic browning (NEB), cloud value and ascorbic acid content were investigated. Second order polynomial models were employed to investigate the effect of independent variables. No significant differences (P < 0.05) in oBrix and titratable acidity were observed. Significant changes were observed in juice pH and colour values. During storage NEB increased while both cloud value and ascorbic acid content decreased. Predictive models developed for colour values, cloud value, NEB and ascorbic acid content were highly significant and were closely correlated to experimental data. Degradation mechanisms are proposed for the key quality parameters.

Andres Ubeda - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of optimal vibrotactile feedback for force controlled upper limb myoelectric prostheses
    Sensors, 2019
    Co-Authors: Andrea Gonzalezrodriguez, Jose L Ramon, Vicente Morell, Gabriel J Garcia, Jorge Pomares, Carlos A Jara, Andres Ubeda
    Abstract:

    The main goal of this study is to evaluate how to optimally select the best vibrotactile pattern to be used in a closed loop control of upper limb myoelectric prostheses as a feedback of the exerted force. To that end, we assessed both the selection of actuation patterns and the effects of the selection of frequency and Amplitude parameters to discriminate between different feedback Levels. A single vibrotactile actuator has been used to deliver the vibrations to subjects participating in the experiments. The results show no difference between pattern shapes in terms of feedback perception. Similarly, changes in Amplitude Level do not reflect significant improvement compared to changes in frequency. However, decreasing the number of feedback Levels increases the accuracy of feedback perception and subject-specific variations are high for particular participants, showing that a fine-tuning of the parameters is necessary in a real-time application to upper limb prosthetics. In future works, the effects of training, location, and number of actuators will be assessed. This optimized selection will be tested in a real-time proportional myocontrol of a prosthetic hand.

Brijesh K Tiwari - One of the best experts on this subject based on the ideXlab platform.

  • effect of sonication on colour ascorbic acid and yeast inactivation in tomato juice
    Food Chemistry, 2010
    Co-Authors: A Adekunte, P. J. Cullen, Brijesh K Tiwari, Amalia G M Scannell, Colm P Odonnell
    Abstract:

    Power ultrasound is recognised as a potential non-thermal technique to inactivate micro-organisms pertinent to fruit juices. In this study tomato juice was sonicated at different Amplitude Levels (24.4–61.0 μm) at a constant frequency of 20 kHz for treatment times (2–10 min) and pulse durations of 5 s on and 5 s off. Hunter colour values (L*, a* and b*), pH, °Brix, titratable acidity, ascorbic acid and yeast inactivation were measured. No significant differences (p < 0.05) in pH, °Brix or titratable acidity were observed. Regression modelling was used to investigate the main effects of Amplitude Level and treatment time. Prediction models were found to be significant (p < 0.05) with low standard errors and high coefficients of determination (R2). Model predictions for critical quality parameters of Hunter colour values (L*, a* and b*), ascorbic acid and yeast inactivation were closely correlated with the experimental results obtained.

  • effect of ultrasound processing on anthocyanins and color of red grape juice
    Ultrasonics Sonochemistry, 2010
    Co-Authors: Brijesh K Tiwari, P. J. Cullen, Ankit Patras, Nigel P Brunton, Colm P Odonnell
    Abstract:

    Abstract Grape juice samples were sonicated with processing variables of Amplitude Level (24.4–61.0 μm) and treatment time (0–10 min) at a constant frequency of 20 kHz and pulse durations of 5 s on and 5 s off. A full factorial experimental design with regression modeling was employed to investigate the main effects of Amplitude Level and treatment time on anthocyanins and color parameters. Significant effects of sonication on major anthocyanins cyanidin-3-O-glucosides (CA), malvanidin-3-O-glucosides (MA) and delphinidin-3-O-glucosides (DA), color values ( L *, a *, b *) and color index (CI) were observed. Prediction models were found to be significant ( p R 2 ). Model predictions for critical quality parameters of anthocyanins (CA; MA; DA), color values ( L *, a *, b *), TCD and CI inactivation were closely correlated to the experimental results obtained. Significant retention of anthocyanin content in grape juice was observed for CA (97.5 %); MA (48.2 %) and DA (80.9%) during sonication. CI and other color combinations ( L * a * b *, L * a * /b * and L * b * /a *) were found to be strongly correlated with anthocyanin content. This study shows that sonication could be employed for as a preservation technique for fruit juice processing where anthocyanin retention is desired.

  • quantitative modelling approaches for ascorbic acid degradation and non enzymatic browning of orange juice during ultrasound processing
    Journal of Food Engineering, 2010
    Co-Authors: V P Valdramidis, P. J. Cullen, Brijesh K Tiwari, Colm P Odonnell
    Abstract:

    Abstract The objective of this study was to develop a deterministic modelling approach for non-enzymatic browning (NEB) and ascorbic acid (AA) degradation in orange juice during ultrasound processing. Freshly squeezed orange juice was sonicated using a 1500 W ultrasonic processor at a constant frequency of 20 kHz and processing variables of Amplitude Level (24.4–61.0 μm), temperature (5–30 °C) and time (0–10 min). The rate constants of the NEB and AA were estimated by a primary model (zero and first order) while their relationship with respect to the processing factors was tested for a number of models, i.e., second order polynomial, different types of Ratkowsky-type model, and an Arrhenius-type model. The non-monotonic behaviour of NEB has been described more accurately by the use of a polynomial model. The rate constants of AA were described by a similar type of model having a monotonic behaviour. A synergistic effect of temperature for different Amplitudes on the rate constant of both NEB and AA was observed, while an antagonistic effect of Amplitude on the rate of NEB was evident. The models with the best fit were integrated to produce contour plots for the combined Amplitude and temperature. The constructed contour plots illustrate that low temperatures and intermediate Amplitudes, i.e., 42.7 μm, result in lower NEB and AA deterioration and consequently better quality orange juice. The overall developed modelling approaches exploit quality data in order to identify the optimal processing regions for eliminating quality deterioration of orange juice during ultrasound processing which is of high importance to the food industry.

  • effect of sonication on retention of anthocyanins in blackberry juice
    Journal of Food Engineering, 2009
    Co-Authors: Brijesh K Tiwari, Colm P Odonnell, P. J. Cullen
    Abstract:

    Abstract Blackberry juice samples were sonicated with processing variables of Amplitude Levels ranging from 40% to 100% at a constant frequency of 20 kHz and sonication times (0–10 min) and pulse durations of 5 s on and 5 s off. The effects of sonication on anthocyanins (Cy3Gl) and colour values ( L , a , and b ) were determined. Response surface methodology (RSM) based on two factor five Level central composite design was applied to determine the effect of Amplitude Level and sonication time. A second-order polynomial model fitted well to the experimental data ( R 2  > 0.89). Significant retention of anthocyanin content (>94%) was observed at the maximum treatment conditions of 100% Amplitude Level for 10 min, indicating stability of anthocyanin during sonication. Colour changes observed during sonication were subtle (TCD ∼ 5%). RSM was demonstrated to be an effective technique to investigate the influence of sonication on colour and anthocyanin retention. Sonication could be employed as a preservation technique for blackberry juice processing where anthocyanin retention is desired.

  • effect of sonication on orange juice quality parameters during storage
    International Journal of Food Science and Technology, 2009
    Co-Authors: Brijesh K Tiwari, Kasiviswanathan Muthukumarappan, C P O Donnell, P. J. Cullen
    Abstract:

    Summary Freshly squeezed orange juice was sonicated at various Amplitude Levels (40%, 70%, 100%), treatment times (2, 6 and 10 min) at a constant frequency of 20 kHz. Samples were stored for periods of up to 30 days at 10 °C. The combined effect of Amplitude Level, treatment time and storage period on pH, oBrix, titratable acidity, colour values (L*, a*, b*), non-enzymatic browning (NEB), cloud value and ascorbic acid content were investigated. Second order polynomial models were employed to investigate the effect of independent variables. No significant differences (P < 0.05) in oBrix and titratable acidity were observed. Significant changes were observed in juice pH and colour values. During storage NEB increased while both cloud value and ascorbic acid content decreased. Predictive models developed for colour values, cloud value, NEB and ascorbic acid content were highly significant and were closely correlated to experimental data. Degradation mechanisms are proposed for the key quality parameters.

Athanasia M Goula - One of the best experts on this subject based on the ideXlab platform.

  • green ultrasound assisted extraction of carotenoids from pomegranate wastes using vegetable oils
    Ultrasonics Sonochemistry, 2017
    Co-Authors: Athanasia M Goula, Maria Ververi, Anna Adamopoulou, Kyriakos Kaderides
    Abstract:

    Abstract The objective of this work was to develop a new process for pomegranate peels application in food industries based on ultrasound-assisted extraction of carotenoids using different vegetable oils as solvents. In this way, an oil enriched with antioxidants is produced. Sunflower oil and soy oil were used as alternative solvents and the effects of various parameters on extraction yield were studied. Extraction temperature, solid/oil ratio, Amplitude Level, and extraction time were the factors investigated with respect to extraction yield. Comparative studies between ultrasound-assisted and conventional solvent extraction were carried out in terms of processing procedure and total carotenoids content. The efficient extraction period for achieving maximum yield of pomegranate peel carotenoids was about 30 min. The optimum operating conditions were found to be: extraction temperature, 51.5 °C; peels/solvent ratio, 0.10; Amplitude Level, 58.8%; solvent, sunflower oil. A second-order kinetic model was successfully developed for describing the mechanism of ultrasound extraction under different processing parameters.

  • ultrasound assisted extraction of pomegranate seed oil kinetic modeling
    Journal of Food Engineering, 2013
    Co-Authors: Athanasia M Goula
    Abstract:

    Abstract In this work, ultrasound-assisted extraction was employed to extract oil from pomegranate seeds. Seed particle size, extraction temperature, solvent/solid ratio, Amplitude Level, and pulse duration/pulse interval ratio were the factors investigated with respect to extraction yield using a central composite design. The optimum operating conditions were found to be: seed particle size, 0.2 mm; extraction temperature, 20  o C; solvent/solid ratio, 20/1; Amplitude Level, 60%; pulse duration/pulse interval ratio, 5/15. Under these optimized conditions, the predicted value for extraction yield was 59.8%. A second-order kinetic model was successfully developed for describing the mechanism of ultrasound extraction under different processing parameters.