Ozônio como agente fungicida na pós-colheita do mamão (Carica papaya L.)
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Data
2012-05-25
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Universidade Federal de Viçosa
Resumo
As doenças fúngicas de pós-colheita, principalmente a antracnose, constituem uma das causas de depreciação do mamão, com perdas na comercialização. O processo normalmente utilizado para controle dessa doença em pós-colheita inclui tratamento hidrotérmico dos frutos a 49 °C durante 20 min, com posterior resfriamento por igual período, além da aplicação de fungicidas. As desvantagens associadas aos tratamentos convencionais tornam necessária a busca de novos métodos de controle da antracnose na pós-colheita do mamão. Uma das alternativas é a utilização do gás ozônio (O3), por se tratar de forte agente oxidante e antimicrobiano, que pode ser gerado no local por meio de uma descarga elétrica, descartando a necessidade de manipulação, armazenamento ou eliminação de embalagens. O presente trabalho teve como objetivo avaliar a eficácia do ozônio dissolvido em água para controle de antracnose em mamões, bem como verificar a influência desse tratamento nas características físs e químicas dos frutos. Foram utilizados mamões (Carica papaya L.) Golden , colhidos no estádio de maturação 1, com até 15% de cor da casca amarela. Para a avaliação do efeito do ozônio no controle de antracnose, os frutos foram inoculados com suspensão de conídios de Colletotrichum gloesporioides e C. magna, na concentração de 2,3 x 106 UFC mL-1. Posteriormente procedeu-se à ozonização dos frutos em tanque com água contendo ozônio dissolvido na concentração de 0,8 mg L-1, pelos períodos de 40, 80, 120 e 160 min. Como controle foram utilizados frutos não ozonizados. Após esse processo, os frutos foram armazenados em câmaras climáticas a 11 °C e 80 a 85% UR por 15 dias. Foram feitas análises nesse período no primeiro e no 15° dia. Posteriormente, a temperatura da câmara foi modificada para 25 °C, sendo feitas análises nos 17°, 19°, 21° e 23° dias de armazenamento. Foram analisados o percentual de área lesionada, produção de CO2, perda de massa fresca, acidez titulável, sólidos solúveis, cor da casca, teor de vitamina C, firmeza da polpa e pH. Durante o armazenamento a 11 °C, não houve aumento significativo de área lesionada por antracnose. Os mamões apresentaram aumento da taxa respiratória, com uma tendência de menor aumento para aqueles expostos ao ozônio. A firmeza da polpa apresentou redução nesse período. Os valores do ângulo Hue (h°) apresentaram decréscimo e os valores de Croma e Diferença de cor aumentaram. A massa fresca dos frutos sofreu decréscimo e os parâmetros acidez titulável, sólidos solúveis, teor de vitamina C e pH não apresentaram variação nesse período. Durante o armazenamento a 25 °C, foi verificado menor percentual de área lesionada nos frutos tratados com ozônio, em comparação aos não tratados. Os frutos expostos ao ozônio dissolvido na água também apresentaram menor perda de firmeza da polpa e menor taxa respiratória ao longo do armazenamento. Os parâmetros de cor (Croma, Hue° e diferença de cor), pH, sólidos solúveis e acidez titulável dos mamões ozonizados não diferiram dos observados nos frutos expostos ao ozônio. Pode-se concluir que a aplicação do ozônio dissolvido na água, na concentração de 0,8 mg L-1, por até 160 min, é eficiente na diminuição da severidade de antracnose na pós-colheita de frutos de mamão Golden , sem, entretanto, afetar negativamente a qualidade dos frutos.
Fungal diseases of postharvest, mainly anthracnose, are one of the causes of papaya depreciation with losses in trading. The process normally used for this disease control in postharvest includes hydrothermal treatment at 49 °C for 20 minutes, followed by cooling for the same period, besides the application of fungicides. Disadvantages linked to conventional treatments lead to search for new methods to control postharvest anthracnose in papaya. One alternative is ozone gas (O3) usage, for being a strong oxidizing and antimicrobial agent, which can be generated on site by an electrical discharge, dismissing the need for handling, storage, or disposal of packaging. This study aimed to evaluate the effectiveness of ozone dissolved in water to control anthracnose in papaya and check the influence of this treatment on these fruits physical and chemical characteristics. Papaya (Carica papaya L.) Golden cultivar was used, harvested at maturity stage 1, with up to 15% yellow color. To evaluate the ozone effect in controlling anthracnose, fruits were inoculated with spore suspension of Colletotrichum gloeosporioides and C. magna at a concentration of 2.3 x 106 CFU mL-1. Subsequently, fruits ozonation was performed in tank with water containing dissolved ozone at a concentration of 0.8 mg L-1 for periods of 40, 80, 120, and 160 minutes. Non-ozonated fruits were used as control. After this process, the fruits were stored in chambers at 11 °C and 80 to 85% RH for 15 days. Analyzes were performed in this period in the first and 15th days. Subsequently, the chamber temperature was changed to 25 °C and analyzes was made on the 17°, 19°, 21°, and 23° days of storage. Data were subjected to variance analysis using SAEG (SAEG, 2007) statistical software. The comparison of analysis mean values of the ozonated or non-ozonated fruit stored for zero and 15 days was performed by the F test at 5% probability. In the second step, fruits stored at 25 °C for eight days were analyzed from the 15th day. Split plot scheme was made and in the parcels there were five periods of exposure (0, 40, 80, 120, and 160 minutes) to Ozone dissolved in water; and in subplots there were five periods of fruits storage (0, 2, 4, 6, and 8 days, except for CO2 production, that in subplot there were four storage periods, from the second day) in a completely randomized design (CRD) with two replicates, except percentage of injured area, with three replicates. Analyzes were of percentage of injured area, CO2 production, fresh mass loss, titratable acidity, soluble solids, skin color, vitamin C content, pulp firmness, and pH. During storage at 11 °C, there was no significant increase in lesioned area by anthracnose. The papayas showed increased respiratory rate with a trend towards smaller increase for those exposed to ozone. The firmness decreased during this period. Values of Hue° decreased and values of Chroma and Color Difference increased. Fruit fresh mass suffered a decrease and parameters suffered titratable acidity, soluble solids, and vitamin C content; pH showed no change during this period. During storage at 25 °C, lowest percentage of lesioned area in fruits treated with ozone was recorded in comparison to untreated fruits. The fruits exposed to ozone dissolved in water also showed less loss of firmness and lower respiration rate during storage. The color parameters (Chroma, Hue°, and Color Difference), pH, soluble solids, and titratable acidity of ozonated papayas did not differ from those observed in fruits exposed to ozone dissolved in water. It can be concluded that the application of ozone dissolved in water at a concentration of 0.8 mg L-1 for up to 160 minutes is efficient in reducing the severity of anthracnose in postharvest of papaya Golden cultivar without, however, adversely affecting fruits quality.
Fungal diseases of postharvest, mainly anthracnose, are one of the causes of papaya depreciation with losses in trading. The process normally used for this disease control in postharvest includes hydrothermal treatment at 49 °C for 20 minutes, followed by cooling for the same period, besides the application of fungicides. Disadvantages linked to conventional treatments lead to search for new methods to control postharvest anthracnose in papaya. One alternative is ozone gas (O3) usage, for being a strong oxidizing and antimicrobial agent, which can be generated on site by an electrical discharge, dismissing the need for handling, storage, or disposal of packaging. This study aimed to evaluate the effectiveness of ozone dissolved in water to control anthracnose in papaya and check the influence of this treatment on these fruits physical and chemical characteristics. Papaya (Carica papaya L.) Golden cultivar was used, harvested at maturity stage 1, with up to 15% yellow color. To evaluate the ozone effect in controlling anthracnose, fruits were inoculated with spore suspension of Colletotrichum gloeosporioides and C. magna at a concentration of 2.3 x 106 CFU mL-1. Subsequently, fruits ozonation was performed in tank with water containing dissolved ozone at a concentration of 0.8 mg L-1 for periods of 40, 80, 120, and 160 minutes. Non-ozonated fruits were used as control. After this process, the fruits were stored in chambers at 11 °C and 80 to 85% RH for 15 days. Analyzes were performed in this period in the first and 15th days. Subsequently, the chamber temperature was changed to 25 °C and analyzes was made on the 17°, 19°, 21°, and 23° days of storage. Data were subjected to variance analysis using SAEG (SAEG, 2007) statistical software. The comparison of analysis mean values of the ozonated or non-ozonated fruit stored for zero and 15 days was performed by the F test at 5% probability. In the second step, fruits stored at 25 °C for eight days were analyzed from the 15th day. Split plot scheme was made and in the parcels there were five periods of exposure (0, 40, 80, 120, and 160 minutes) to Ozone dissolved in water; and in subplots there were five periods of fruits storage (0, 2, 4, 6, and 8 days, except for CO2 production, that in subplot there were four storage periods, from the second day) in a completely randomized design (CRD) with two replicates, except percentage of injured area, with three replicates. Analyzes were of percentage of injured area, CO2 production, fresh mass loss, titratable acidity, soluble solids, skin color, vitamin C content, pulp firmness, and pH. During storage at 11 °C, there was no significant increase in lesioned area by anthracnose. The papayas showed increased respiratory rate with a trend towards smaller increase for those exposed to ozone. The firmness decreased during this period. Values of Hue° decreased and values of Chroma and Color Difference increased. Fruit fresh mass suffered a decrease and parameters suffered titratable acidity, soluble solids, and vitamin C content; pH showed no change during this period. During storage at 25 °C, lowest percentage of lesioned area in fruits treated with ozone was recorded in comparison to untreated fruits. The fruits exposed to ozone dissolved in water also showed less loss of firmness and lower respiration rate during storage. The color parameters (Chroma, Hue°, and Color Difference), pH, soluble solids, and titratable acidity of ozonated papayas did not differ from those observed in fruits exposed to ozone dissolved in water. It can be concluded that the application of ozone dissolved in water at a concentration of 0.8 mg L-1 for up to 160 minutes is efficient in reducing the severity of anthracnose in postharvest of papaya Golden cultivar without, however, adversely affecting fruits quality.
Descrição
Palavras-chave
Fitossanitário, Antracnose, phytosanitary, Anthracnose
Citação
COSTA, André Rodrigues da. Ozone as a fungicidal agent in post-harvest papaya (Carica papaya L.). 2012. 87 f. Dissertação (Mestrado em Construções rurais e ambiência; Energia na agricultura; Mecanização agrícola; Processamento de produ) - Universidade Federal de Viçosa, Viçosa, 2012.