Gamma radiation in papaya harvested at three stages of maturation

Abstract

Papaya is a fragile, perishable fruit, highly accepted worldwide. To keep the quality of papaya from harvest to the consumers, conservation techniques are often used; among them is the application of gamma irradiation. The objective of this work was to evaluate gamma irradiation in papayas harvested at three degrees of maturation, in order to increase shelf life. Papayas were harvested in perfect quality conditions and selected by skin coloration into three distinct degrees of maturation: maturation 0, or beginning of yellow coloration; maturation 1, yellow stripes more developed, and maturation 2, one third yellow. Half of them were irradiated with 0.75 kGy, while the other half became control treatment. They were analyzed in four periods of conservation, which were 1 DAI (days after irradiation refrigerated at 11 ± 1°C), 14 DAI, 14 DAI + 3 DRT (room temperature at 24° ± 2°C) and 14 DAI + 6 DRT. The papaya maturation degree at harvest did not influence the radiation effect. Irradiation maintained firmness of papaya and, therefore, delayed ripening; modified the green color of papaya to a lighter, more intense tone, which determined more homogeneity in the development of the skin's yellow color (greater values of L* and croma). There was no effect of irradiation in papaya weight loss, occurrence of diseases, croma of flesh color, pH and total soluble solids contents. Key words: post-harvest, food conservation, gamma irradiation, tropical fruits, shelf life RADIAÇÃO GAMA EM MAMÃO PAPAIA COLHIDO EM TRÊS ESTÁDIOS DE MATURAÇÃORESUMO: O mamão é um fruto frágil, perecível, muito apreciado mundialmente. Para que a qualidade do mamão se mantenha da colheita até os consumidores, técnicas de conservação são utilizadas, sendo uma destas a aplicação de radiação gama. O objetivo deste trabalho foi avaliar a aplicação de irradiação gama em mamões colhidos em diferentes estádios de maturação com a intenção de aumentar a vida útil pós-colheita. Mamões foram colhidos em perfeitas condições de qualidade e selecionados pela coloração amarela em três fases distintas: maturação 0, ou início da coloração amarela; maturação 1, com estrias amarelas mais desenvolvidas, e maturação 2, com um terço da casca já amarelo. Metade destes foi irradiada com 0,75 kGy e a outra se tornou testemunhas. A análise se deu em quatro períodos de conservação sendo estes 1 DAI (dias após a irradiação sob refrigeração a 11 ± 1°C), 14 DAI, 14 DAI + 3 DTA (dias a temperatura ambiente a 24°± 2°C) e 14 DAI + 6 DTA. Não houve diferença entre os mamões irradiados em diferentes estádios de maturação. A irradiação promoveu manutenção da firmeza do mamão e, portanto, retardo no amadurecimento; modificou a cor verde do mamão para tons mais claros e mais intensos o que determinou maior homogeneidade no desenvolvimento da cor amarela da casca (valores de brilho e croma maiores). Não houve efeito da irradiação na perda de massa, aparecimento de doenças, na cor interna dos frutos, no pH e no teor de sólidos solúveis. Palavras-chave: pós-colheita, conservação de...

Evaluation of Physiological and Orgaleptic Properties of Mango cv. Kesar as Influenced by Ionizing Radiation and Storage Temperature

“…The possible reasons may be that medium to lower dose of irradiation can break chemical bonds, increase membrane permeability and metabolic activity, which will lead to more water vapor movement to intercellular space and maintain the texture of the fruit and another reason may be that the changes in pectin by irradiation are possible cause of the radiation induced softening (Zhao et al 1996). These results are in agreement with findings of Moreno et al (2006), El-Salhy et al (2006) and Lacroix et al (1990) in mango; Pimentel and Walder (2004) in banana and Singh and Pal (2007) and Singh and Pal (2009) in guava. Significantly better texture score was recorded at the full ripening stage in fruits stored at 12 0 C, ambient temperature and in CA (12 0 C) storage compared to fruits stored at 9 0 C temperature, which may be due to retardation of the biochemical changes and ripening process at desired temperature (Mane, 2009) and significantly decrease in texture during storage of fruits was due to changes in nature of pectin substances which cementing the cell wall and hydrolysis of starch, hemicelluloses and cellulose during ripening of fruit (Leopold, 1964).This finding is in conformity with the findings of Waskar and Masalkar (1997) in mango; Purvoko (2002) in banana.…”

“…Mango is susceptible to chilling injury and an optimum temperature of 12-13 0 C is generally recommended (Gomez -Lim, 1993;Yimyong et al, 2011). Irradiation of fruits has been successfully shown to delay ripening (Pimentel and Walder, 2004) and is the most recent commercial phytosanitary treatment for fresh commodities. Irradiation is a physical process for the treatment of foods compared to conventional process like heating or freezing.…”

Disponibilidade de cálcio em leite bovino tratado por raios gama

“…Esse método de conservação apresenta característica única de poder ser aplicada em alimentos congelados (FARKAS, 1998). há vários estudos que demonstram a irradiação como método para aumento da conservação de alimentos (IEMMA et al, 1999;PIMENTEL;WALDER, 2004;SPOTO, 2008).…”

Exposure of Medium Dose Gamma Rays and Storage Conditions Influenced the Weight Loss and Ripening of Alphonso Mango

“…It is because of this fact that fruits must be stored under specific storage conditions, not only to maintain weight loss but also to prolong ripening. Mango is susceptible to chilling injury and an optimum temperature of 12-13 0 C is generally recommended (Gomez-Lim, 1993).Irradiation of fruits has been successfully shown to delay ripening (Pimentel and Walder, 2004). As well as irradiation is a physical process for the treatment of foods akin to conventional process like heating or freezing.…”