Aplicação de cálcio pré-colheita em goiabeira (Psiudium guajava) cv. Paluma
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Data
2019-09-02
Autores
Ribeiro, Luiza Rocha
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A goiaba ocupa lugar de destaque dentre as frutas brasileiras em termos de produção, além de seu aroma agradável, sabor e alto valor nutricional. A Paluma é uma das cultivares de goiabeira mais cultivadas no país e no estado de São Paulo, em razão de sua dupla aptidão (mesa e indústria), contudo, é uma das mais perecíveis. Tal problema representa um dos principais entraves do cultivo de goiaba ‘Paluma’ destinada ao mercado de fruta fresca. Neste sentido, aplicações de cloreto de cálcio podem minimizar estes problemas, visto que o cálcio promove benefícios como a manutenção da firmeza e o aumento do período de armazenamento e do valor nutricional, por meio do incremento nos teores de ácido ascórbico e de cálcio. Assim, objetivou-se avaliar o efeito de aplicações pré-colheita de cloreto de cálcio sobre a qualidade dos frutos da goiabeira cv. Paluma. O trabalho foi realizado na Fazenda Experimental São Manuel, da Faculdade de Ciências Agronômicas da UNESP, campus Botucatu – SP, durante o ciclo 2017/2018. O pomar, com três anos de idade, sem irrigação e com espaçamento de seis metros entre linhas e quatro entre plantas, foi podado e conduzido conforme recomendações para a cultura. O delineamento adotado foi o de parcelas subdivididas no tempo, sendo avaliadas cinco concentrações de CaCl2 (0; 0,5; 1,0; 1,5 e 2,0 %) aos 0, 2, 4 e 6 dias de armazenamento. As concentrações de cálcio foram aferidas nas folhas antes e depois das aplicações, e nos frutos logo após a colheita. Foram realizadas avaliações físicas, físico-químicas e enzimáticas nos frutos. As aplicações de CaCl2 promoveram aumento linear do teor de Ca nas folhas e incremento de 27% de Ca em frutos tratados com a concentração de 1,1%. Verificou-se menor perda de massa e menor incidência de podridões com as concentrações de 1,2 e 0,9%, respectivamente. As aplicações de CaCl2 também promoveram incremento no comprimento dos frutos e nos teores de ácido ascórbico. Contudo, houve redução dos teores de açúcares redutores e acidez titulável. Em adição, observou-se redução da atividade da pectinametilesterase nos frutos tratados e as aplicações de 1,1 e 1,2% de CaCl2 reduziram a atividade da poligalacturonase aos 2 e 6 dias. Face ao exposto, a utilização de CaCl2 em pré-colheita de goiaba ‘Paluma’ é uma técnica promissora e pode ser utilizada como ferramenta para diminuir a perecibilidade dos frutos.
Guava occupies a prominent place among the most produced Brazilian fruits, mainly because of its pleasant aroma, taste and high nutritional value. The “Paluma” cultivar is one of the most cultivated in the country and in the State of São Paulo due to its dual aptitude, either for table and industry, however, it is among the most perishable. This issue represents one of the main obstacles to the cultivation of “Paluma” guava for the market of fresh fruit. Therefore, calcium chloride applications may minimize these problems, as calcium promotes benefits such as firmness maintenance, and increasing shelf life and nutritional value by increasing the amount of ascorbic acid and calcium. Hence, the objective of this study was to evaluate the effect of the pre-harvest application of calcium chloride on the quality of fruits of the guava cv. Paluma. The experiment was carried out at the Experimental Farm São Manuel, of the College of Agronomic Sciences of UNESP, Campus of Botucatu – SP, during the production cycle of 2017/2018. The three-years-old orchard was pruned and conducted according to the recommendations for the culture but without irrigation and spacing of six meters between rows and four meters between plants. The experimental design was a randomized block design, in a time split-plot scheme. The plots were represented by five CaCl2 concentrations (0, 0.5, 1.0, 1.5 and 2%) while the subplots were represented by the storage time (0, 2, 4 and 6 days). The calcium content was measured in the leaves before and after application, and in the fruits immediately after harvest. Physical, physicochemical and enzymatic evaluations were performed on the fruits. CaCl2 applications promoted a linear increase of Ca content in the leaf and an increase of 27% of the Ca in the fruits treated with a concentration of 1.1%. There were less mass loss and lower incidence of rots at the concentrations of 1.2 and 0.9% of CaCl2, respectively. CaCl2 applications also promoted an increase in fruit length and ascorbic acid content. However, there was a reduction in reducing sugar levels and titratable acidity. In addition, pectin methylesterase activity was reduced in the fruits, and the applications of 1.1 and 1.2% of CaCl2 reduced polygalacturonase activity at 2 and 6 days of storage. Given the above, the use of CaCl2 in pre-harvest of the guava cv. “Paluma” is a promising technique and can be used as a tool to decrease fruit perishability.
Guava occupies a prominent place among the most produced Brazilian fruits, mainly because of its pleasant aroma, taste and high nutritional value. The “Paluma” cultivar is one of the most cultivated in the country and in the State of São Paulo due to its dual aptitude, either for table and industry, however, it is among the most perishable. This issue represents one of the main obstacles to the cultivation of “Paluma” guava for the market of fresh fruit. Therefore, calcium chloride applications may minimize these problems, as calcium promotes benefits such as firmness maintenance, and increasing shelf life and nutritional value by increasing the amount of ascorbic acid and calcium. Hence, the objective of this study was to evaluate the effect of the pre-harvest application of calcium chloride on the quality of fruits of the guava cv. Paluma. The experiment was carried out at the Experimental Farm São Manuel, of the College of Agronomic Sciences of UNESP, Campus of Botucatu – SP, during the production cycle of 2017/2018. The three-years-old orchard was pruned and conducted according to the recommendations for the culture but without irrigation and spacing of six meters between rows and four meters between plants. The experimental design was a randomized block design, in a time split-plot scheme. The plots were represented by five CaCl2 concentrations (0, 0.5, 1.0, 1.5 and 2%) while the subplots were represented by the storage time (0, 2, 4 and 6 days). The calcium content was measured in the leaves before and after application, and in the fruits immediately after harvest. Physical, physicochemical and enzymatic evaluations were performed on the fruits. CaCl2 applications promoted a linear increase of Ca content in the leaf and an increase of 27% of the Ca in the fruits treated with a concentration of 1.1%. There were less mass loss and lower incidence of rots at the concentrations of 1.2 and 0.9% of CaCl2, respectively. CaCl2 applications also promoted an increase in fruit length and ascorbic acid content. However, there was a reduction in reducing sugar levels and titratable acidity. In addition, pectin methylesterase activity was reduced in the fruits, and the applications of 1.1 and 1.2% of CaCl2 reduced polygalacturonase activity at 2 and 6 days of storage. Given the above, the use of CaCl2 in pre-harvest of the guava cv. “Paluma” is a promising technique and can be used as a tool to decrease fruit perishability.
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Palavras-chave
Frutas, Cálcio, Enzimas