• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Master's Dissertation
DOI
https://doi.org/10.11606/D.11.2019.tde-19112019-164653
Document
Author
Full name
Bruna Letícia Felippin
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
Piracicaba, 2019
Supervisor
Committee
Kluge, Ricardo Alfredo (President)
Jacomino, Angelo Pedro
Lima, Giuseppina Pace Pereira
Mattiuz, Ben-hur
Title in Portuguese
Aditivos para a redução do escurecimento enzimático de escarola minimamente processada
Keywords in Portuguese
Cichorium endivia var. latifolia L.
Ácido cítrico
Antioxidantes
Cisteína
Conservação
Escurecimento enzimático
Polifenoloxidase
Abstract in Portuguese
A escarola (Cichorium endivia var. latifolia L.) é uma hortaliça da família Asteraceae, de folhas largas, lisas e alongadas com bordos dentados. Entre as folhosas, apresenta grande potencial para o mercado de produtos minimamente processados. No entanto, o processamento mínimo desencadeia resposta de estresse devido às lesões causadas durante os cortes necessários, levando ao colapso celular e, permitindo assim, o contato dos substratos com enzimas oxidativas associadas ao escurecimento. O uso de aditivos possui ação antioxidante eficaz para o controle do escurecimento enzimático, inibindo a atividade da polifenoloxidase (PPO), que é a principal responsável pelo escurecimento enzimático. O objetivo do presente estudo foi avaliar a eficiência da cisteína, isoladamente ou em associação com o ácido cítrico, na redução do escurecimento enzimático e conservação da qualidade de escarola minimamente processada. Foram realizados dois experimentos. No primeiro experimento foi avaliada a inibição do escurecimento enzimático das escarolas minimamente processadas (MP), as folhas de escarolas foram submetidas ao corte manual em tiras, e a manutenção da qualidade foi através da aplicação de cisteína em cinco doses (0,0%, 0,05%, 0,1%, 0,2% e 0,3%). Após os tratamentos, as escarolas foram armazenadas sob refrigeração a 5°C e 95% UR por 12 dias. No segundo experimento avaliou-se a eficiência dos aditivos cisteína e ácido cítrico na inibição do índice de escurecimento manutenção da qualidade e conservação da escarola MP submetidas ao corte manual em tiras. Os tratamentos foram controle (sem aditivos conservantes); 1% de ácido cítrico; 0,2% de cisteína e 0,2% de cisteína + 1% de ácido cítrico armazenadas sob refrigeração a 5°C e 95% UR por 12 dias. No primeiro experimento foram realizadas as análises de taxa respiratória, produção de etileno, sólidos solúveis, acidez titulável, luminosidade e cor, índice de escurecimento, capacidade antioxidante, atividade da polifenoloxidase e compostos fenólicos totais e as avaliações foram realizadas aos 0, 3, 6, 9 e 12 dias. Ao final desse experimento, constatou-se que a aplicação de 0,2% de cisteína foi o mais indicada entre as doses testadas para a diminuição do índice de escurecimento e manutenção da qualidade da escarola minimamente processada por 12 dias. No segundo experimento foram realizadas aos 0, 3, 6, 9 e 12 dias, as análises de sólidos solúveis, luminosidade e cor, índice de escurecimento, capacidade antioxidante, atividade da polifenoloxidase e compostos fenólicos totais. Neste experimento, constatou-se que a dose 0,2% de cisteína proporcionou o menor índice de escurecimento e melhorias no aspecto visual das folhas pelo período de 12 dias.
Title in English
Additives for the reduction of enzymatic darkening of minimally processed endive
Keywords in English
Cichorium endivia var. latifolia L.
Antioxidants
Citric acid
Conservation
Cysteine
Enzymatic browning
Polyphenoloxidase
Abstract in English
The escarole (Cichorium endivia var. latifolia L.) is a vegetable of the Asteraceae family, of broad leaves, smooth and elongated with toothed edges. Among the hardwood, it presents great potential for the market of minimally processed products. However, minimal processing triggers stress response due to injuries caused during the necessary cuts, leading to cellular collapse and thus allowing contact of substrates with oxidative enzymes associated with darkening. The use of additives has an effective antioxidant action to control the enzymatic browning, inhibiting the activity of polyphenoloxidase (PPO), which is the main responsible for the enzymatic browning. The aim of this study was to evaluate the efficiency of cysteine, alone or in association with citric acid, in the reduction of enzymatic browning and preservation of the quality of minimally processed escarole. Two experiments were carried out. In the first experiment, the inhibition of enzymatic darkening of the minimally processed escarole (MP) was evaluated, the leaves of the escarole were subjected to manual cutting in strips, and the maintenance of the quality was through the application of cysteine in five doses (0.0%, 0.05%, 0.1%, 0.2% and 0.3%). After the treatments, the escarole were stored under refrigeration at 5°C and 95% RH for 12 days. In the second experiment, the efficiency of cysteine and citric acid additives was evaluated in the inhibition of the index of darkening maintenance of the quality and preservation of the MP escarole submitted to manual cutting in strips. The treatments were controlled (no preservatives additives); 1% citric acid; 0.2% cysteine and 0.2% cysteine + 1% citric acid stored under refrigeration at 5°C and 95% RH for 12 days. In the first experiment, the analysis of respiratory rate, ethylene production, soluble solids, titratable acidity, luminosity and color, darkening index, antioxidant capacity, polyphenoloxidase activity and phenolic compounds were performed. And evaluations were performed at 0, 3, 6, 9 and 12 days. At the end of this experiment, it was found that the application of 0.2% of cysteine was the most indicated among the doses tested to decrease the darkening index and maintenance of the quality of the minimally processed escarole for 12 days. In the second experiment, the analyses of soluble solids, luminosity and color, darkening index, antioxidant capacity, polyphenoloxidase activity and total phenolic compounds were performed at 0, 3, 6, 9 and 12 days. In this experiment, it was found that the dose 0.2% of cysteine provided the lowest rate of darkening and improvements in the visual aspect of the leaves for the 12-day period.
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
Publishing Date
2019-11-28
 
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
CeTI-SC/STI
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2024. All rights reserved.