Conservação de goiaba ‘Pedro Sato’ utilizando recobrimentos à base de hidroxipropil metil celulose e cera de abelha
Data
2019-03-15
Autores
Formiga, Anderson dos Santos
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
As goiabas são frutas tropicais e climatéricas, de curto período de conservação pós-colheita à temperatura ambiente. Com o objetivo de prolongar a vida útil de goiabas ‘Pedro Sato’, avaliou-se o efeito de recobrimentos comestíveis a base de hidroxipropil metil celulose (HPMC) e de cera de abelha (CA) nas concentrações de 10%, 20% e 40%, e com concentrações de 8% (cap. 2) e 6% (cap. 3) de sólidos totais, em goiabas armazenadas por oito dias a 21-22 °C. No 1° experimento (cap. 2), o HPMC+CA formaram uma atmosfera modificada ao redor dos frutos provocando um retardamento do processo de amadurecimento das goiabas. Os frutos com recobrimento apresentaram redução na perda de massa, manutenção da coloração verde e maior firmeza. O tratamento com HPMC+20% CA foi o que apresentou os melhores resultados na manutenção da qualidade dos frutos, apresentando aos oito dias características físico-químicas comparáveis aos frutos controle no segundo dia de armazenamento, representando um ganho de seis dias, na vida de prateleira das goiabas ‘Pedro Sato’. No 2° experimento (cap. 3), o HPMC+CA reduziu a taxa respiratória, inibiu a síntese de etileno e retardou o processo de amadurecimento dos frutos. O tratamento com HPMC+20% CA também foi o que apresentou os melhores resultados na manutenção da qualidade dos frutos, reduzindo a atividade da enzima Poligalacturonase e atrasando o amadurecimento das goiabas ‘Pedro Sato’ sem promover a atividade da enzima Álcool desidrogenase e consequentemente a fermentação dos frutos.
Guavas are tropical climacteric fruits with a short post-harvest shelf life at room temperature. This study aims to extend the shelf life of red guavas 'Pedro Sato' using edible coatings of hydroxypropyl methylcellulose (HPMC) and beeswax (BW) at concentrations of 10%, 20%, and 40%, and with concentrations of 8% (chapter 2) and 6% (chapter 3) of total solids, in guavas stored for eight days at 21-22 °C. In the 1st experiment (chapter 2), the HPMC+CA produced a modified atmosphere around the fruit, delaying ripening process. The coatings reduced the loss of mass, maintained the green color, and increased the firmness. The treatment with HPMC+20% BW also provided the best maintenance of fruit quality. On the eighth day, fruit with this coating showed the same physicochemical characteristics of control fruit in the second day of storage, which represents a gain of six days in the shelf life of guavas 'Pedro Sato'. In the 2nd experiment (chapter 3), the HPMC+CA reduced the respiratory rate, inhibited ethylene synthesis and delayed the fruit ripening process. The treatment with HPMC+20% CA presented the best results in maintaining fruit quality, reducing the activity of the Polygalacturonase enzyme and delaying the maturation of 'Pedro Sato' guavas without promoting the activity of the Alcohol dehydrogenase enzyme and consequently the fermentation of fruits.
Guavas are tropical climacteric fruits with a short post-harvest shelf life at room temperature. This study aims to extend the shelf life of red guavas 'Pedro Sato' using edible coatings of hydroxypropyl methylcellulose (HPMC) and beeswax (BW) at concentrations of 10%, 20%, and 40%, and with concentrations of 8% (chapter 2) and 6% (chapter 3) of total solids, in guavas stored for eight days at 21-22 °C. In the 1st experiment (chapter 2), the HPMC+CA produced a modified atmosphere around the fruit, delaying ripening process. The coatings reduced the loss of mass, maintained the green color, and increased the firmness. The treatment with HPMC+20% BW also provided the best maintenance of fruit quality. On the eighth day, fruit with this coating showed the same physicochemical characteristics of control fruit in the second day of storage, which represents a gain of six days in the shelf life of guavas 'Pedro Sato'. In the 2nd experiment (chapter 3), the HPMC+CA reduced the respiratory rate, inhibited ethylene synthesis and delayed the fruit ripening process. The treatment with HPMC+20% CA presented the best results in maintaining fruit quality, reducing the activity of the Polygalacturonase enzyme and delaying the maturation of 'Pedro Sato' guavas without promoting the activity of the Alcohol dehydrogenase enzyme and consequently the fermentation of fruits.
Descrição
Palavras-chave
Coberturas comestíveis, HPMC, Psidium guajava L., Pós-colheita, Enzimas de parede, Álcool desidrogenase