Integração de tratamentos pós-colheita físicos (calor e ultrassons) e biocontrolo na conservação de pera Rocha inteira e na aptidão para processamento

• Author(s): Coelho, Duarte Francisco Pequeno
• Date: 2015
• Persistent ID: http://hdl.handle.net/10400.5/8527
• Origin: Repositório da UTL
• Subject(s): Rocha pear; storage; heat treatment; ultrasound; biocontrol; minimal processing
• Document Type: Master thesis
• Language: Portuguese
• Advisor(s): Abreu, Marta Maria Nogueira; Martins, Margarida Moldão; Alegria, Carla Sofia Marques
• Contributor(s): Repositório da Universidade de Lisboa

Description

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia

The integrated effects of heat treatments, ultrasound and biocontrol (Blossom Protect™) were evaluated as alternatives to postharvest storage of Rocha pear and to the production of fresh-cut pear. Based on response surface methodology to assess thermal binomials decontamination efficiency, the 40 ºC / 40 min condition (Top - immersion the pears in water) was selected due to the achieved reduction level (~1 and ~2 LogCFU.g-1 to aerobic microorganisms and yeast and molds, respectively) without changing the fresh characteristics. Ultrasound application had a non-significant effect in reducing fruits contaminating flora and didn’t introduced further decontamination effects when combined with Top, confirming Top single application effectiveness. During fruit postharvest storage (7 ºC, 60 days), the effects of the combination of heat treatment and biocontrol were surpassed by Top single application since the later proved to be more effective in achieving significant decontamination levels and to control rot development. Regarding the use of Top as an alternative treatment to the standard use of sodium hypochlorite as a decontamination agent, has shown potential in decontamination, effective control of microbial development and color maintenance of the fresh-cut pear during storage (5 ºC, 15 days) suggest that Top is a viable alternative to this production