EFEITO DE INJÚRIAS MECÂNICAS NA FIRMEZA E COLORAÇÃO DE GOIABAS DAS CULTIVARES PALUMA E PEDRO SATO
Data
2001-08-01
Autores
MATTIUZ, BEN-HUR
Durigan, José Fernando [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Fruticultura
Resumo
O objetivo deste trabalho foi avaliar o efeito das injúrias mecânicas por impacto, compressão ou corte na firmeza e coloração de goiabas 'Paluma' e 'Pedro Sato', colhidas no estádio de maturação de vez e armazenadas sob condições de ambiente. Na injúria por impacto, os frutos foram deixados cair, em queda livre, de uma altura de 1,20 m, sofrendo dois impactos, em lados opostos da porção equatorial do fruto. Na injúria por compressão, os frutos foram submetidos a um peso de 3 kg, por 15 minutos. Para a injúria por corte, foram efetuados dois cortes, no sentido longitudinal dos frutos, de exatamente 30 mm de comprimento por 2 mm de profundidade. Os frutos injuriados foram colocados em bandejas de isopor e armazenados sob condições de ambiente (23,4±1 °C, 62±6 % UR). A firmeza dos frutos submetidos ao impacto e compressão foi calculada pela relação peso(N)/área injuriada (m2). A evolução da coloração foi feita através de leituras diárias em reflectômetro Minolta CR 200b, procurando comparar a coloração da área lesionada com a da área não lesionada do mesmo fruto. Com relação à injúria por compressão, não se detectou diferença significativa entre as cultivares testadas, mas com relação ao impacto, os frutos da 'Paluma' tiveram uma firmeza significativamente maior que os da 'Pedro Sato'. A área injuriada mostrou maior escurecimento e retardo no amarelecimento, indicado pelo maior ângulo Hue, típico do amadurecimento de goiabas. Os valores de cromaticidade foram sempre inferiores nas áreas injuriadas, de ambas as cultivares, indicando menor síntese de pigmentos carotenóides nessas regiões. Os frutos da 'Pedro Sato' foram caracterizados como mais escuros e mais esverdeados que os da 'Paluma' ao longo do período de armazenamento, independentemente das injúrias.
This work aimed to evaluate the effect of mechanical injuries, impact, compression or cuts on firmness and epidermal color of fruits of two guava cultivars, harvested at mature-green ripeness stage at room temperature. Impact injury was obtained by dropping the guavas twice, from a height of 1.20 m on a hard surface. Compression injury was done with the fruits submitted to a 3 kg load for 15 minutes. Cutting fruits obtained cut injury, twice longitudinally to 30 mm in length and 2 mm depth. Injured fruits were placed on trays and stored at ambient conditions (23.4±1 °C, 62±6 % RH). The firmness of fruits submitted to impact and compression injuries was calculated by the relationship of weight (N)/injured area (m²). Epidermal color changes were determined by a Minolta CR 200b reflectometer. Daily color measurement was done to compare the color of the injured area with the non-injured area of the same fruit. The compression test indicates that there are no significant differences between the tested cultivars as for flesh firmness. However, 'Paluma' fruits had better firmness than 'Pedro Sato' fruits, when submitted to impact damages. The injured area was darker than intact areas while Hue angle was always higher in these areas, indicating retard in yellowing, typical of guava ripening. Chroma values were always lower in injured areas, for both cultivars. 'Pedro Sato' fruits were characterized as darker and more greenish than 'Paluma' along the storage period, independently of the injuries.
This work aimed to evaluate the effect of mechanical injuries, impact, compression or cuts on firmness and epidermal color of fruits of two guava cultivars, harvested at mature-green ripeness stage at room temperature. Impact injury was obtained by dropping the guavas twice, from a height of 1.20 m on a hard surface. Compression injury was done with the fruits submitted to a 3 kg load for 15 minutes. Cutting fruits obtained cut injury, twice longitudinally to 30 mm in length and 2 mm depth. Injured fruits were placed on trays and stored at ambient conditions (23.4±1 °C, 62±6 % RH). The firmness of fruits submitted to impact and compression injuries was calculated by the relationship of weight (N)/injured area (m²). Epidermal color changes were determined by a Minolta CR 200b reflectometer. Daily color measurement was done to compare the color of the injured area with the non-injured area of the same fruit. The compression test indicates that there are no significant differences between the tested cultivars as for flesh firmness. However, 'Paluma' fruits had better firmness than 'Pedro Sato' fruits, when submitted to impact damages. The injured area was darker than intact areas while Hue angle was always higher in these areas, indicating retard in yellowing, typical of guava ripening. Chroma values were always lower in injured areas, for both cultivars. 'Pedro Sato' fruits were characterized as darker and more greenish than 'Paluma' along the storage period, independently of the injuries.
Descrição
Palavras-chave
Psidium guajava, Postharvest, impact, compression, cut, flesh firmness, Color, Psidium guajava, Pós-colheita, impacto, compressão, corte, firmeza de polpa, coloração
Como citar
Revista Brasileira de Fruticultura. Sociedade Brasileira de Fruticultura, v. 23, n. 2, p. 277-281, 2001.