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Doctoral Thesis
DOI
10.11606/T.64.2007.tde-12092008-151127
Document
Author
Full name
Lucimeire Pilon
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
Piracicaba, 2007
Supervisor
Committee
Spoto, Marta Helena Fillet (President)
Arthur, Valter
Durigan, Jose Fernando
Porto, Ernani
Wosiacki, Gilvan
Title in Portuguese
Conservação de abacaxi minimamente processado utilizando como coadjuvantes cloreto de cálcio, película comestível e radiação gama
Keywords in Portuguese
Abacaxi
Alginato de sódio
Glúten de trigo
Irradiação
Película comestível
Processamento mínimo
Abstract in Portuguese
Essa pesquisa teve como objetivo obter o abacaxi como alimento tipo conveniência, submetido ao processamento mínimo e tratamento com cloreto de cálcio, películas comestíveis à base de alginato e glúten de trigo, e irradiação. Os frutos foram lavados, sanificados com Sumaveg® (Dicloro-S-Triazinatriona Sódica), na concentração de 200 mg L-1 de cloro livre, a 7ºC, durante 15 minutos, e descascados manualmente. A polpa foi fatiada em leques de aproximadamente 1 cm de espessura, enxagüadas com 20 mg L-1 de cloro livre, durante 3 minutos, e drenadas por 3 minutos. No primeiro experimento as amostras foram submetidas aos tratamentos: cloreto de cálcio 1% + solução de glúten vital; cloreto de cálcio 1% + alginato de sódio 1%; e controle. No segundo experimento as amostras foram submetidas aos tratamentos: cloreto de cálcio 1% + solução de glúten vital + irradiação com 2,3 kGy; cloreto de cálcio 1% + irradiação com 2,3 kGy; irradiação com 2,3 kGy; e controle. O acondicionamento foi realizado em bandejas rígidas de polietileno tereftalato (PET), com cerca de 250 g de fruta. A irradiação foi realizada em irradiador multipropósito de Cobalto-60, com atividade de 92 kCi e taxa de dose de 2,3 kGy h-1. As amostras foram armazenadas a 5 ± 1ºC e analisadas a cada dois dias, num total de 12 dias. No primeiro experimento, os valores de pH e acidez titulável apresentaram leves alterações e semelhança entre os tratamentos. Houve decréscimo no teor de ácido ascórbico em todos os tratamentos. Todos os tratamentos escureceram ao longo do armazenamento. Apesar dos valores terem sido próximos entre os tratamentos, os abacaxis tratados com cloreto de cálcio + glúten apresentaram textura mais firme, menores perda de líquido, atividade da peroxidase e polifenoloxidase, produção de CO2 e etileno e contagens de microrganismos mesófilos e bolores e leveduras. Não houve presença de E. coli e de Salmonella. A contagem de microrganismos do grupo dos coliformes totais foi baixa em todos os tratamentos e ocorreu apenas em amostras isoladas durante o período de armazenamento. Na análise sensorial, as amostras tratadas com cloreto de cálcio + glúten apresentaram as notas mais baixas para textura, aparência e aroma; já o sabor ficou comprometido a partir do 4o dia de armazenamento. No segundo experimento, os valores de pH e acidez titulável apresentaram pequenas alterações e semelhança entre os tratamentos. Houve decréscimo no teor de ácido ascórbico em todos os tratamentos; no entanto, as amostras tratadas com cloreto de cálcio + glúten + 2,3 kGy retiveram mais essa vitamina. A textura mais firme e as menores perda de líquido e atividade da peroxidase e polifenoloxidase ocorreram nas amostras tratadas com cloreto de cálcio + 2,3 kGy. Todos os tratamentos escureceram ao longo do armazenamento. As amostras mais escuras foram as tratadas com cloreto de cálcio + glúten + 2,3 kGy e as irradiadas com 2,3 kGy. As maiores taxa respiratória e síntese de etileno ocorreram nas amostras tratadas com cloreto de cálcio + glúten + 2,3 kGy. As menores contagens de microrganismos psicrotróficos, mesófilos, e bolores e leveduras ocorreram nas amostras à base de cloreto de cálcio + glúten + 2,3 kGy. Não houve presença de E. coli e de Salmonella. A contagem de microrganismos do grupo dos coliformes totais foi baixa em todos os tratamentos e ocorreu apenas em algumas amostras durante o período de armazenamento. Apenas o controle manteve as características sensoriais acima do limite de aceitabilidade durante todo o armazenamento. A textura das demais amostras foi rejeitada no 8º dia. O sabor ficou comprometido desde o 1º dia de armazenamento nas amostras à base de cloreto de cálcio + glúten + 2,3 kGy
Title in English
Conservation of minimally processed pineapple using calcium chloride, edible coating and gamma radiation.
Keywords in English
Edible coating
Irradiation
Minimal processing
Pineapple
Sodium alginate
Wheat gluten
Abstract in English
The aim of this study was to obtain a convenience type pineapple subjected to fresh-cut process and calcium chloride, wheat gluten and alginate-base edible coating and irradiation treatments. The fruits were washed, sanitized with Sumaveg® (Sodium Dichloro-s-Triazinetrione) in a 200 mg L-1 chlorine-free solution at 7ºC for 15 minutes, and then manually peeled. The peeled fruits were sliced into 1 cm thick slices, rinsed in 20 mg L-1 chlorine-free solution for 3 minutes and drained for 3 minutes. In the first experiment, the samples were treated with: 1% calcium chloride + vital wheat gluten solution; 1% calcium chloride + 1% alginate solution; and control. In the second experiment, the samples were treated with: 1% calcium chloride + vital wheat gluten solution + 2.3 kGy; 1% calcium chloride + 2.3kGy; irradiation with 2.3kGy; and control. The packing consisted of rigid polyethylene terephthalate (PET) trays with around 250 g of fruit. The irradiation was performed in a Cobalt-60 multipurpose irradiator with 92 kCi activity and dose value of 2.3 kGy h-1. The samples were stored at 5 ± 1ºC and evaluated every other day for 12 days. In the first experiment pH and titratable acidity values showed slight variations but were similar between the treatments. There was a decrease in ascorbic acid values in all treatments. Browning was noticed in all treatments over the storage period. Although the values between the treatments were similar, the pineapple treated with calcium chloride + gluten showed firmer texture, less liquid loss, and lower values of polyphenoloxidase and peroxidase activities and CO2 and ethylene production. Mesophiles and mold and yeast counts were also reduced. No Salmonella and E. coli were detected. Total coliform counts were low in all the treatments and appeared in just a few isolated samples during the storage period. Sensory analyses showed that the samples treated with calcium chloride + gluten had the lower scores for texture, appearance, and aroma; the flavor was compromised from the 4th storage day onward. In the second experiment the pH and titratable acidity values showed small changes but were similar between the treatments. There were a decrease in the ascorbic acid values in all treatments; nevertheless, the samples treated with calcium chloride + gluten + 2.3 kGy retained more of this vitamin than the other treatments. Firmer texture, less liquid loss, and lower values of polyphenoloxidase and peroxidase activities were noticed in the samples with calcium chloride + 2.3 kGy. Browning was noticed in all treatments over the storage period. The darker samples were the ones treated with calcium chloride + gluten + 2.3 kGy, and irradiated with 2.3 kGy. Higher respiratory rate and ethylene synthesis were noticed in the samples treated with calcium chloride + gluten + 2.3 kGy. The lowest psychrotrophic, mesophiles, and mold and yeast counts occurred in the samples treated with calcium chloride + gluten + 2.3 kGy. No Salmonella and E. coli were detected. Total coliform counts were low in all the treatments and appeared in just a few samples during the storage period. Only the control kept the sensorial attributes within the acceptability limit during the storage period. The texture in all the other samples was unacceptable from the 8th day onward. The flavor was compromised from the first storage day onward in the samples with calcium chloride + gluten + 2.3 kGy
 
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Publishing Date
2008-10-01
 
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