Termos para indexação: Diospyros kaki, fisiologia pós-colheita, produção de etileno, tanino, amadurecimento. ASTRINGENCY REMOVAL OF 'GIOMBO' PERSIMMON FRUIT IN DIFFERENT EXPOSURE PERIODS TO ETHYL ALCOHOL VAPORABSTRACT -The purpose of this research was to study the effect of exposure period to ethyl alcohol vapor on astringency removal of persimmon fruits (Diospyros kaki L.) cv. Giombo. Fruits were exposed to alcohol vapor for 24, 36 and 48 hours at 20°C and 95% RH. Chemical and physical characteristics of fruits were measured for ten days, at two day intervals. Soluble tannin content, flesh firmness, water loss, pH, soluble solids, titratable acidity and ascorbic acid content were measured. This research showed that 24 and 36 hours were equally efficient in the astringency removal of fruits, although the analysis of other quality indices showed that fruits exposed for 24 hours exhibited better quality. The flesh firmness underwent a linear decrease in terms of time. The best period for consumption of the fruits was placed between the 4 th and 8 th day after the treatment. Fruits became edible at the 4 th day after the treatment, when the content of soluble tannins was under 0.1%, imperceptible to taste, and the flesh firmness was kept for 8 days after the treatment.

Resumo -O objetivo deste trabalho foi avaliar os efeitos do cloreto de cálcio na qualidade do abacaxi 'Pérola' minimamente processado. Os tratamentos, arranjados em delineamento inteiramente casualizado e dispostos em esquema fatorial 3x5, consistiram das concentrações de CaCl 2 e dos períodos de armazenamento, com três repetições. Frutos previamente sanitizados foram descascados mecanicamente, fatiados manualmente e imersos em solução de CaCl 2 a 1% e a 2% e em água (controle), durante 30 segundos. As fatias foram acondicionadas em embalagens de polietileno tereftalato e mantidas à temperatura de 4±1°C durante períodos de 0, 3, 6, 9 e 12 dias. A textura não foi influenciada por nenhum dos fatores estudados. Constatou-se menor atividade peroxidásica nos frutos tratados com CaCl 2 2%. Quanto à coloração, a imersão em solução de CaCl 2 1% resultou em fatias mais escurecidas, com menor valor L* e maior valor a* ao final do período de armazenamento. A utilização de CaCl 2 em abacaxi 'Pérola' minimamente processado não proporciona efeitos benéficos na textura, e interfere negativamente na coloração da polpa do fruto.Termos para indexação: Ananas comosus, cor, textura, vida de prateleira. Effect of calcium chloride on quality of fresh-cut 'Pérola' pineappleAbstract -The objective of this research was to evaluate the effects of calcium chloride on quality of freshcut 'Pérola' pineapple. The experimental design was a completely randomized in a 3x5 factorial scheme, and the treatments were represented by the CaCl 2 concentration and storage time, each one with three replicates. Fruits were sanitized, peeled mechanically, sliced manually and dipped into water (control) and in CaCl 2 solutions (1% and 2%) for 30 seconds. Slices were placed in polyethylene terephtalate packages and stored at 4±1°C during periods of 0, 3, 6, 9 and 12 days. Texture was not influenced by any of the studied factors. Smaller peroxidase activity in the samples submitted to CaCl 2 2% was verified. Fresh-cut pineapple slices dipped in CaCl 2 1% showed more browning, presenting smaller L* value and larger a* value at the end of the storage period. The use of CaCl 2 in fresh-cut 'Pérola' pineapple does not provide beneficial effects on the texture and interfere negatively on the flesh color of fruit.

This study aimed to analyze the cuticle thickness and pattern of epicuticular wax deposition in 'Gala' and 'Galaxy' apple cultivars (Malus domestica Borkh,)

The purpose of this research was to determine the shelf life of minimally processed (MP) 'Pérola' pineapples treated with ascorbic acid (AA) and citric acid (CA) based on physical, chemical, sensorial and microbiological attributes. Slices were dipped into drinking water (control) or combined solutions of AA:CA (%) (1.0:0.5 and 1.0:1.0) with sodium hypochlorite (NaClO 20 mg L -1 ) for 30 seconds. The samples were conditioned in polyethylene terephtalate packages and stored at 4±1 °C per 13 days. The low peroxidase activity in the slices treated with antioxidant combinations was related to low pH values observed in these samples. The treatments 1.0:0.5 and 1.0:1.0 (AA:CA, %) favored maintenance of the initial a* values and avoided the pulp browning. The ascorbic acid increased more than double on the 2 nd day in the treated slices. By the 4 th day the CO 2 values suggested a higher respiratory activity in the slices treated with anti-browning compounds. The antioxidant treatments did not produce detectable residual flavors in the MP pineapple. Regardless of microbiological safety during the 13 days of cold storage, the control slices can be kept by 6 days, afterwards the color and dehydration become strong enough to affect the appearance. On the other hand, MP 'Pérola' pineapples treated with 1.0:0.5 (AA:CA, %) and NaClO (20 mg L -1 ) can be stored for 8 days at 4±1 ºC, which represents the extension of the shelf life in 2 days. After this period the overripe odor starts to develop.Key words: Ananas comosus, minimal processing, enzymatic browning, residual flavor, microbiological safety. Vida útil de abacaxis minimamente processados tratados com ácido ascórbico e ácido cítrico ResumoProcurou-se determinar a vida útil de abacaxis 'Pérola' minimamente processados (MP), tratados com ácido ascórbico (AA) e ácido cítrico (AC), com base nos atributos físicos, químicos, sensoriais e microbiológicos. As fatias foram imersas em água (controle) ou em soluções combinadas de AA:AC (%) (1,0:0,5 e 1,0:1,0) com adição de hipoclorito de sódio (NaOCl 20 mg L -1 ), durante 30 segundos. As amostras foram acondicionadas em embalagens de polietileno tereftalato e mantidas à temperatura de 4±1 °C durante 13 dias. A baixa atividade da peroxidase nas fatias tratadas foi relacionada aos baixos valores de pH observados nessas amostras. Os tratamentos 1,0:0,5 e 1,0:1,0 (AA:AC, %) favoreceram a manutenção dos valores iniciais de a* e evitaram o escurecimento da polpa. A concentração de ácido ascórbico aumentou mais que o dobro, no 2.° dia, nas fatias tratadas. Os valores de CO 2 observados no 4.° dia sugeriram a ocorrência de maior atividade respiratória nas fatias tratadas com os compostos antioxidantes. Os tratamentos antioxidantes não produziram sabor e odor residuais no abacaxi MP. Apesar de comprovada a segurança microbiológica durante os 13 dias de armazenamento, as fatias-controle podem ser mantidas por seis dias, uma vez que o escurecimento e o aspecto desidratado prejudicam a aparência do produto após esse período. Abacaxis...

Resumo O objetivo deste trabalho foi avaliar o efeito de diferentes temperaturas durante o período de exposição ao vapor de álcool etílico sobre a qualidade dos frutos de caquizeiro cultivar Giombo. Os frutos foram expostos ao vapor de álcool etílico durante 42 horas, sob temperaturas de 10, 20 ou 30°C e 95% de umidade relativa. As características químicas e físicas dos frutos foram avaliadas durante nove dias, em intervalos de três dias. As variáveis analisadas foram: grau de taninos solúveis, firmeza da polpa, perda de matéria fresca, sólidos solúveis totais, acidez total titulável e teor de ácido ascórbico. O tratamento para remoção da adstringência pode ser realizado a 10, 20 ou 30°C, por 42 horas. Constatou-se grau de taninos solúveis muito baixo ao sexto dia após o tratamento. A temperatura de 30°C promoveu maior rapidez no processo de perda da adstringência, mas os frutos apresentaram menor firmeza de polpa e maior perda de matéria fresca que os frutos submetidos a 20 ou 10°C.Termos para indexação: Diospyros kaki, substância tanante. Astringency removal of Giombo persimmon fruits submitted to different temperaturesAbstract The purpose of this research was to study the effect of different temperatures during the exposure period to ethyl alcohol vapor on quality of persimmon fruits cv. Giombo. Fruits were exposed to alcohol vapor for 42 hours at 10, 20, or 30°C and 95% RH. Chemical and physical characteristics of fruits were measured for nine days, at three day intervals. Soluble tannin degree, flesh firmness, water loss, soluble solids, titratable acidity and ascorbic acid content were measured. Treatment to astringency removal can be accomplished under temperatures of 10, 20 or 30°C, for 42 hours. Degree of soluble tannins was very low at the sixth day after the treatment. The temperature of 30°C promoted higher speed in the process of astringency loss; however, the fruits showed decrease in the flesh firmness and higher-up water loss to the fruits submitted to 20 or 10°C.Index terms: Diospyros kaki, tanning agents.(1) Aceito para publicação em 18 de maio de 2001.