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Effect of Pressure Assisted Thermal Processing on Bioactive Compounds and Antioxidant Activity of Mate and Mate Sweetened with Stevia rebaudiana

  • Author / Creator
    Chourio Chavez, Angelica M
  • Mate Ilex paraguarensis is gaining considerable interest worldwide due to its health benefits in the prevention of chronic diseases like cancer, mainly attributed to its content of bioactive compounds. In this study, the effect of Pressure Assisted Thermal Processing (PATP) on total phenolics, total antioxidant activity, and individual bioactive compounds (chlorogenic acid, caffeic acid, quercetin, rutin, theobromine) of mate, mate sweetened with Stevia rebaudiana and model systems was investigated. Mate, Stevia leaves and mate sweetened with Stevia (2.5% w/v) were treated at 10-600 MPa/25-120ºC/1-5 min. The total phenolics (115%) and total antioxidant activity (400%) content of mate significantly increased at 100 MPa/120oC/1 min and 600 MPa/120oC/1 min, respectively, compared to untreated mate. Also, temperature and pressure had a significant effect on the increase of quercetin, caffeic acid, and rutin contents on treated mate at 100 MPa/120oC/1 min. However, chlorogenic acid content significantly decreased up to 91% compared to untreated mate. A significant increase of caffeine from 22.05  2.85 to 35.85  2.59 mg/g mate and theobromine from 15.29 2.02 to 23.99  0.02 mg/g mate was obtained at 100 MPa/120oC/1 min compared to untreated mate. Mate sweetened with Stevia resulted in an increase up to 88% of total phenolics and up to 74% of total antioxidant activity compared to untreated mate. High correlation (R2>0.90) between polyphenol and antioxidant activity was observed on PATP treated mate and Stevia leaves. Moreover, mate sweetened with Stevia leaves resulted in higher release of bioactive compounds compared to mate+commercial Stevia powder due to the bioactive compounds and antioxidant properties of Stevia leaves. In model systems of pure compounds, the increase of temperature from 25 to 75oC had no significant effect on quercetin, rutin, caffeic acid and chlorogenic acid contents. However, the increase of pressure from 100 to 300 MPa had a significant impact on the decrease of chlorogenic acid content (p<0.05). The effect of PATP (10-600 MPa/75-120oC/1-5min) on enzymatic activity of polyphenoloxidase (PPO) and peroxidase (POD) of Stevia leaves was also studied. The optimum condition to a complete reduction of PPO and POD enzymatic activity was 600MPa/120oC/1 min. These results highlight the potential of PATP to release bioactive compounds and enhance antioxidant activity of mate and mate sweetened with Stevia, ensuring an effective inactivation of degradative enzymes and promoting the development of ready-to-drink mate-based beverages with health benefits.

  • Subjects / Keywords
  • Graduation date
    Spring 2019
  • Type of Item
    Thesis
  • Degree
    Master of Science
  • DOI
    https://doi.org/10.7939/r3-mfyn-7x26
  • License
    Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.