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Previous issue date: 2009-07-21 === Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior === Minimally processed products are safe and ready to eat, in spite of adding value, has a
short life. Edible coatings can be an important tool to ensure the quality and increase the
shelf life of minimally processed products, including persimmon. The 'Mikado' variety
Persimmon has astringency and need a specific astringency process to get a minimally
processed product with quality. Therefore, the objective of this work was to develop and
characterize the edible coatings for use in 'Mikado' minimally processed persimmon. It
was necessary to determine the exposure time of the fruit to alcohol vapor until the
decrease of astringency. It was performed the flowchart for the fresh-cut of persimmon
evaluating the quality of the final product. Evaluations of thickness, gas permeability,
mechanical properties of coatings applied were also performed. It was also verified the
efficiency of use 70% alcohol (7.00 mL ?lcool.Kg-1 fruit) to reduce astringency. There
were performed the following analysis: firmness, pH, total soluble solids (? Brix), total
titratable acidity, total tannins and weight loss and sensory analysis during the process.
These analyses were necessary to determine the time of exposure to the alcohol vapor to
decrease the concentration of soluble tannic acids in fruit that it was not tasted by
panelists and determine that concentration. It was evaluated persimmon storage with
and without coatings. Three experiments were conducted during this work. In the first
experiment, it was set up two coatings which were used in the second trial of minimally
processed. It was evaluated four different types of coatings: cassava starch, sodium
alginate, carboxymethyl cellulose (CMC) and bovine gelatin. In the first experiment
(edible coating), it was set up two coatings which were used in the experiment of
minimally processed. Four different types of coatings were evaluated: cassava starch,
sodium alginate, carboxymethyl cellulose (CMC) and bovine gelatin. In the second
experiment (astringency reduction) it was defined the time required to keep the fruits in
alcohol atmosphere to reduce total soluble tannins tasted by panelists. The times tested
were: 10 hours, 36 hours, 55 hours, 83 hours, 107 hours, 130 hours and 155 hours. It
was defined a flowchart for persimmon minimally processed. The best coatings applied
in minimally processed persimmon were the cassava starch and CMC. The firmness of
the fruit remained until to 55 hours of exposure to alcohol vapor. Fruits were exposure
to 83 hours or up caused loss firmness below that it is commercially tolerated. The
astringency was not tasted by panelists from 55 hours exposure of alcohol vapor. The
threshold detection of total soluble tannin in the pulp of fruit was 0.8161 ?g.100g-1. The
tannins content decrease with the increasing exposure of fruit to alcohol vapor. The
reduction of astringency with 70% alcohol vapor may not be the most indicated method
due to high losses in this step (21.76%). The minimally processed fruits treated with
CMC coating showed less dark spots in the pulp than the other treatments and all
treatments were microbiological adequates. === Produtos minimamente processados s?o produtos seguros e de pronto consumo, que
apesar de agregar valor, possui uma vida ?til mais reduzida. Os revestimentos
comest?veis podem se constituir em importante ferramenta para garantir a qualidade e
estender a vida ?til de produtos minimamente processados, entre eles, o caqui. O caqui
Mikado por ser adstringente necessita de um processo adequado de destaniza??o para
gerar um produto minimamente processado de qualidade. Diante disto, este trabalho
teve como objetivos o desenvolvimento e caracteriza??o de revestimentos comest?veis
para a utiliza??o em caqui Mikado minimamente processado, determina??o do tempo
necess?rio de exposi??o ao vapor de ?lcool para que o fruto n?o apresente adstring?ncia
e elabora??o de um fluxograma para o processamento m?nimo de caqui com avalia??o
da qualidade do produto final. Para o desenvolvimento e caracteriza??o dos
revestimentos foram realizadas avalia??es de espessura, permeabilidade gasosa,
propriedades mec?nica e pr?via sensorial do caqui Mikado minimamente processado
tratados com os revestimentos comest?veis. Definiram-se dois revestimentos [amido de
mandioca e carboximetilcelulose (CMC)], a partir de quatro revestimentos (amido de
mandioca, alginato de s?dio, CMC e gelatina bovina) para serem testados em caqui
minimamente processado. Foi tamb?m avaliado o tempo de exposi??o ao vapor de
?lcool a 70% (7mL de ?lcool.Kg-1 de fruto), por meio de an?lises f?sicas, qu?micas e
sensoriais. Tais analises foram necess?rias para determinar o tempo de exposi??o ao
vapor de ?lcool que diminuiria a concentra??o de ?cido t?nico sol?vel nos frutos at? que
este n?o fosse mais sensorialmente percept?vel, determinando esta concentra??o e
verificando-se se o fruto tinha firmeza adequada ao minimamente processado. Desta
forma, foi poss?vel determinar o limiar de detec??o dos taninos sol?veis
(0,8161?g.100g-1) e o tempo de exposi??o ao vapor de ?lcool mais adequado para o
processamento m?nimo, que provavelmente estava entre 55 e 83 horas, sendo que os
tempos testados foram de: 10 horas; 36 horas; 55 horas; 83 horas; 107 horas; 130 horas;
e 155 horas. A firmeza dos frutos se manteve adequada at? as 55 horas de exposi??o ao
?lcool, sendo que um tempo igual ou superior a 83 horas de exposi??o causou perda de
firmeza a um n?vel abaixo do tolerado comercialmente. Por fim foi obtido um
fluxograma da produ??o de caqui Mikado minimamente processado e avaliado o
armazenamento com e sem revestimentos, sendo realizado para isto analises f?sicas,
qu?micas, microbiol?gicas e sensoriais ao longo do per?odo de armazenamento de 10
dias. Para a realiza??o deste experimento (processamento m?nimo de caqui) utilizou-se
revestimentos de amido de mandioca e de CMC, e o tempo de destaniza??o foi de 70
horas. Verificou-se que a destaniza??o neste tempo pode n?o ser a mais adequada
devido ?s altas perdas verificadas nesta etapa (21,76% dos frutos n?o se mostraram
adequados ao processamento m?nimo). Os frutos minimamente processados tratados
com revestimento de CMC apresentaram-se com menos manchas na polpa que os
demais tratamentos e todos os tratamentos mostraram-se adequados
microbiologicamente.
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