João Nunes Nogueira

Influence of some browning treatments on the quality of the apple Bruckner do Brasil processed by freezing and freeze drying

The present paper deals with the study of three browning treatments (blanching, ascorbic acid and SO2) and their influence on the quality of frozen and freeze-dried apple slices of the variety Bruckner do Brasil. Immediately upon arrival, one third of the fruits was processed. Another third was held in storage at 1°C for three weeks and the remainder was left under the same conditions for six weeks, being both immediately processed after their respective storage time. For freezing, blanching was the best browning treatment for all attributes of quality, except for color, in which the SO2 and the ascorbic acid were more efficient. In terms of overall quality the ascorbic acid was slightly superior to SO2. For freeze - drying, the SO2 was in general the best treatment. However, none of the treatments controlled the browning of the freeze-dried product efficiently.

Influência de alguns métodos de processamento nas propriedades organoléticas da maçã em pedaços: variedade Bruckner do Brasil

Foi estudada a influencia de tres tratamentos com. a finalidade de evitar o escurecimento enzimatico (branqueamento, SO2 e acido ascorbico) e de tres metodos de processamento (appertizacao, congelacao e liofilizacao) nas propriedades organoleticas da maca em pedacos da variedade Bruckner do Brasil. Imediatamente apos seu recebimento, uma terca parte das frutas foi processada. Outra terca parte foi colocada em câmara fria a 1°C por tres semanas e a restante deixada sob as mesmas condicoes por seis semanas, sendo estas duas ultimas processadas imediatamente apos os respectivos tempos de armazenamento previo. Os resultados mostraram que o melhor tratamento foi a combinacao branqueamento-appertizacao para todos os atributos de qualidade, exceto para cor, em que as combinacoes SO2-congelacao e acido ascorbico-congelacao foram superiores. A appertizacao foi o metodo de processamento mais adequado para a variedade em estudo. O armazenamento previo nao melhorou as propriedades organoleticas da maca em pedacos, chegando a ser ate prejudicial para a maioria dos tratamentos utilizados.

Influência de alguns compostos químicos na retenção do ácido ascórbico em frutas liofilizadas

No presente trabalho foram estudados os efeitos do EDTA, do metabissulfito de potassio e de metabissulfito + acido tartarico na retencao do acido ascorbico durante a liofilizacao e posterior armazenamento de cereja das Antilhas e de morango. Os resultados e as analises estatisticas mostraram que todos os tratamentos foram significativamente superiores as testemunhas, observando-se tambem que o tratamento metabissulfito de potassio + acido tartarico foi ligeiramente melhor que os demais tratamentos, porem nao estatisticamente significativo.

Estudo sobre o processamento do palmito (Euterpe edulis Mart.) por apertização: II. influência de métodos de controle do escurecimento enzímico

The influence of some anti-browning treatments on the canning of heart-of-palm (Euterpe edulis Mart.) was studied. The results showed that ascorbic acid was, in general, the best treatment to control enzymatic browning for all atributes of quality except for texture, in which blanching was superior. For the first three cuts, in particular, ascorbic acid was better than blanching for all attributes of quality. On the other hand, for the last cuts, blanching presented the best results, except for flavor. This attribute of quality was better preserved in the canned heart-of-palm by ascorbic acid.

Estudo sobre o controle de qualidade do palmito (Euterpe edulis Mart.) processado por apertização

Com o objetivo de melhorar as condicoes de seu controle de qualidade, foi estudada a influencia de alguns parâmetros nos atributos de qualidade do palmito (Euterpe edulis Mart.) processado por apertizacao. Os resultados mostraram que, dependendo dos tratamentos empregados, alguns atributos de qualidade podem sofrer variacoes importantes durante o processamento e armazenamento do produto enlatado.

Efeito de reguladores do crescimento nas características tecnológicas das frutificações do tomateiro (Lycopersicon esculentum Mill cv. Gigante Piedade)

The effect of growth regulators (CCC, Alar, Giberelin and Ethephon) on the technological characteristics of tomatoes was studied. The regulators were sprayed only once over the whole plant, 38 days after seeding. The tomatoes were harvested twice, 60 and 100 days after the regulators were applied. Quality was evaluated through physical (soluble solids and color), chemical (pH, ascorbic acid content and pectinesterase activity) and sensory (color, flavor, external and internal aspects) analysis. Within the range of this esperiment the authors concluded that the growht regulators did not affect pH. color (both on physical and sensory evaluations), soluble solids and ascorbic acid contents. The PE activity was slightly affected, being significant in the interaction between treatment and time of harvest. Flavor was not affected but the tomatoes from the second harvest were significantly better than those from the first one. The internal and external aspects were significantly affected by the regulators, being Ethephon the worst and CCC the best. In terms of overall quality, the preference of the panel members rated treatment 2 (CCC) the best, followed by 5 (Ethephon) 1 (Control), 4 (Giberelin) and 3 (Alar).

Influência da embalagem e do período de armazenamento no teor residual de SO2 em banana passa

In the present work residual SO2 in banana figs was determined after treatment with 2% potassium metabisulfite solution, packaging in aluminum foil, cellophane, polyetylene film or aluminum foil+polyetylene and stores from 15 to 105 days at room temperature. It is concluded that: a) the product loses SO2 after processing; b) the cellophane a continuous flow system. It is concluded that: a) the product loses SO2 after processing; b) the cellophane retains more SO2 in the banana figs, than aluminum foil or polyetylene film; c) the amounts of SO2 found in the banana figs at any time after 15 days of storage were below the limit established by the CNNPA (National Commission for Food Standards and Regulations).

Influência de alguns métodos de processamento na qualidade da maça em pedaços: III - variedade Rome Beauty

Este trabalho teve como objetivo o estudo da influencia de armazenamento previo, de tratamentos para evitar o escurecimento enzimico (branqueamento, SO2 e acido ascorbico) e de metodos de processamento (appertizacao, congelacao e liofilizacao) na qualidade da maca em pedacos da variedade Rome Beauty. Apos seu recebimento na planta piloto, metade das frutas foi imediatamente processada, permanecendo o restante armazenado por seis semanas a 4,4°C para ser posteriormente processado. O melhor tratamento para a variedade em estudo, foi a combinacao branqueamento-congelacao para todos os atributos de qualidade, exceto para cor com seis semanas de armazenamento previo, em que a combinacao SO2-liofilizacao foi superior. De um modo geral, a congelacao foi o metodo de processamento mais adequado. Para a congelacao, o branqueamento e o SO2 foram considerados os melhores tratamentos para evitar o escurecimento enzimico. O armazenamento previo teve alguma influencia na qualidade da maca em pedacos, de modo que, as amostras correspondentes a parte nao armazenada foram superiores para quase todos os atributos de qualidade.

Estudo preliminar da influência da concentração de SO2 no controle do escurecimento enzímico da banana passa

Two investigations were conducted to find ways to control enzymic browning in the elaboration of banana figs. Bananas were treated with SO2 by immersion in a solution of potassium metabisulfite of which were studied concentration, temperature, pH and time of immersion as well as the resting time of the fruits, after the treatments. The results showed that the best treatment was to dip the fruits for 10 minutes in the 2% solution at 40°C, and pH 2,9. Resting before drying did not improve the products. The shelf life of the products, with the best treatment reached 3 months, with commonly used celophane wraping. Preliminary tests, pre-heating before immersing the fruits showed the possibility of improving the penetration of SO2 and so the enzymic browning control.

Influência da interação do ph da solução de metabisulfito de potássio e da remoção da película externa, na elaboração de banana passa

The present work was conducted to find ways to control enzymic browning by poliphenoloxidase in the elaboration of banana figs. Bananas were treated with SO2 by immersion in a solution of potassium metabisulfite of which, concentration, temperature, pH and time of immersion were studied, as well as the interaction between these treatments and the removal of the fruit external skin. It was concluded that the best treatment was to immerse for 10 minutes in the 2% solution at 40°C, independently of pH control. The interaction of pH and removing or not the external skin of the bananas had no influence on the ensymic browning.