ABSTRACT In this study, chemical changes during the development of acerola, cultivar Okinawa, were evaluated. The biochemical alterations during the development of the acerola cultivar Okinawa were evaluated, to determine the peroxidase activity (POD) and its thermal stability. Peroxidase (POD) has been considered the main enzyme responsible for the quality deterioration of fruits. Additionally, characteristics evaluated in this study can be important postharvest quality criteria for fruit processing, screening and breeding. Changes in physiological development were evaluated by the determination of moisture content, ascorbic acid, ashes, total and reducing sugars, pectin, chlorophyll a and b, amounts of anthocyanins, flavonols and total carotenoids. These biochemical determinations may serve as a basis for further improvement of techniques for predicting and modeling the optimal harvesting time. The values of chlorophylls, anthocyanins, flavonols, and carotenoids were higher in the peel rather than in the pulp (p < 0.05). Acerola presents high levels of ascorbic acid. The development of acerola (from opening of flowers to maturation of fruits) was of 25 days. The increase of the values for total and reducing sugars, anthocyanins, carotenoids, the solubilization of pectic acid and degradation of chlorophyll suggested that physiological maturation and harvest day occurred on days 19 and 23 after anthesis, respectively. The specific activity of POD was higher in the green stage. Maximum POD activity was observed at pH 6.5 and 45 ºC. Total inactivation was not achieved, suggesting the presence of isoenzymes with high thermal resistance. A loss of 50% of activity occurred after 4 minutes of treatment at 80 °C.

O objetivo deste trabalho foi caracterizar e correlacionar a maturidade e qualidade das primeiras variedades de uvas apirênicas 'BRS Clara', 'BRS Linda', 'BRS Morena', mais a 'Seleção Avançada 8' em fase de lançamento, comparado-as com a variedade norte-americana 'Crimson Seedless', conforme as Normativas Brasileiras/2002 e os padrões para exportação. A Seleção Avançada 8 é avermelhada escura, possui cacho grande, com baga muito grande tipo elipsoide; a 'BRS Morena' é preta com cacho médio, baga grande tipo elipsoide a globosa; a 'BRS Linda' é verde clara, de cacho grande; e a 'Crimson', rósea de cacho pequeno, ambas, com bagas médias a grandes e elipsoides; a 'BRS Clara' éverde amarelada, possui cacho médio, baga pequena tipo elipsoide alongada.Todas atendem ao mercado nacional quanto ao diâmetro mínimo de 12 mm. A 'BRS Clara' não atende aos diâmetros exigidos para exportações. As uvas tintas 'BRS Morena' e 'Crimson Seedless' apresentam bagas mais firmes. O pH, a acidez titulável e os sólidos solúveis atendem aos padrões oficiais. Os cachos maiores são os menos ácidos e apresentam as melhores relações sólidos solúveis/acidez titulável, inferindo serem os mais doces, quando maduros.

The objective of this study was to characterize and correlate maturity and quality of the first varieties of Brazilian seedless grapes 'BRS Clara', 'BRS Linda', 'BRS Morena', and 'Advanced Selection 8' compared with the American variety 'Crimson Seedless' in compliance with the Brazilian Normative/2002 and export standards Advanced Selection 8' is dark reddish, has large clusters, and is a very large ellipsoid berry; 'BRS Morena' is black with medium sized clusters and large berry shaped as ellipsoid to globoid; 'BRS Linda' is light green and has large sized clusters; 'Crimson' is pink and has small clusters with berries varying from medium to large sizes and ellipsoid shaped; and 'BRS Clara' is green yellowish has medium sized clusters and small berry of elongated ellipsoid shape. All varieties evaluated meet the standard for domestic market established as berry size minimum diameter 12 mm. 'BRS Clara' does not meet the export requirements of diameter. Berries of the red grapes 'BRS Morena' and 'Crimson Seedless' are firmer. The pH, titratable acidity, and soluble solids meet the official standards. Larger clusters are less acidic and present higher soluble solids/titratable acidity ratios implying that they are the sweetest type when ripe.

Diante dos riscos e das limitações advindos do cultivo exclusivo de abacaxizeiros Pérola e Smooth Cayenne e visando à variabilidade genética, o Estado da Paraíba estuda material genético diversificado: os híbridos Emepa-01, Imperial e MD-2. objetivando a caracterização destes novos híbridos, avaliaram-se alguns parâmetros químicos e a atividade da bromelina nas polpas e nas cascas de todas as cultivares. o abacaxi Smooth Cayenne apresentou o menor pH (3,44 para polpa e 3,91 para a casca) e a maior acidez titulável (0,56g de ácido cítrico para 100g de polpa e 0,52g de ácido cítrico para 100g de casca), sendo a cultivar mais ácida. Dentre as polpas, as dos abacaxis Pérola e Smooth Cayenne contiveram níveis de açúcares redutores, não redutores e totais significativamente maiores (p<0,05) do que os híbridos, apesar de estes terem valores mais elevados (maior que 30,00) da relação sólidos solúveis e acidez titulável e, consequentemente, maior aceitação pelo consumidor. o extrato bruto da cultivar Imperial apresentou maior atividade proteolítica e teor de proteína tanto na polpa (56,41 U/ml e 7,50 mg de proteína/ml) quanto na casca (68,56 U/ml e 10,40 mg de proteína/mL). Para a atividade específica, a casca do abacaxi Pérola (10,01 U/mg de proteína) contém valor significativamente mais elevado que os encontrados nas demais amostras. No entanto, dentre as polpas, a da cultivar Imperial (7,49 U/mg de proteína) apresenta atividade específica significativamente superior (p<0,05) às demais.

Due to the risks and limitations which has come from exclusive cultivation of Pérola and Smooth Cayenne - pineapple plant - and aiming genetic variability, the state of Paraiba provides diversified genetic material cultivating the hybrids Emepa - 01, Imperial and MD-2 pineapple varieties. Aiming the biochemical characterization of those new hybrids, some biochemical parameters were determined: pulp and rind of those cultivars including bromelain activity. Smooth Cayenne pineapple had introduced the smallest pH (3,44 for pulp and 3,91 for rind) and the biggest titled acidity (0,56g of citric acid for 100g of pulp and 0,52g of citric acid for 100g of rind), being the most acid cultivar. Among the pulps the Pérola and the Smooth Cayenne varieties presented levels of reduced, non-reduced and total sugar significantly higher (p<0,05) than the hybrids, in spite of having more elevated values (bigger than 30,00) of the ratio of soluble solids to titled acidity, consequently resulted on a better acceptation by consumers. The crude extract of the Imperial cultivar had the biggest proteolytic activity and protein content in the pulp (56,41 U/ml and 7,50 mg of protein/mL) as well as in the rind (68,56 U/mL and 10,40 mg of protein/mL). For the specific activity, the rind of Pérola pineapple (10,01 U/mg of protein) provided more significantly elevated value (p<0,05) than those ones observed in the other samples. However, the pulp from Imperial cultivar (7,49 U/ mg of protein) presented considerably superior activity if compared to the rest.

Cajás verde-maduros foram armazenados em recipientes de vidro fechados e a concentração de oxigênio (O2) e de dióxido de carbono (CO2) foi determinada em intervalos de 6 horas. Após a coleta das amostras da atmosfera, as tampas dos recipientes foram abertas para renovação do ar. O aumento da concentração do CO2 e o decréscimo de O2 durante o armazenamento demonstraram o comportamento climatérico da respiração do cajá. A liberação máxima de CO2 54,2 mL kg-1 h-1 e a absorção máxima de O2 49,0 mL kg-1 h-1 ocorreram após 186 horas da colheita, quando o fruto alcançou qualidade máxima, iniciando em seguida a senescência. O quociente de respiração no climatérico máximo foi 1,11, indicando a oxidação de carboidratos. Os Sólidos solúveis aumentaram de 9,1 °Brix iniciais para 13,7 °Brix no climatérico máximo, enquanto a acidez titulável total diminuiu de 1,55% iniciais para 1,40% no climatérico mínimo, 1,00% no climatérico máximo e 0,80% no pós-climatérico. Comportamento similar foi observado em relação aos teores de ácido ascórbico. A Clorofila diminuiu e os carotenóides aumentaram continuamente durante o amadurecimento do Cajá.

Mature fruit from the yellow mombin (Spondias mombin) was monitored for its respiration activity. Mature green fruit from the yellow mombin was stored in closed glass chambers and the concentration of oxygen and carbon dioxide at the end of a six hour respiration period was determined. At the same interval of time, the lid of the chamber was opened for air renewal. The increase in carbon dioxide and decrease in oxygen concentration demonstrated that the fruit was climacteric. The maximum liberation of CO2 54.2 mL Kg-1 h-1 and maximum absorption of O2 49.0 mL Kg-1 h-1 occurred 186 hours after the harvest which, obviously, represented the optimum fruit quality after the senescence process started. The respiratory quotient of fruit at a climacteric maximum was 1.11 representing the oxidation of carbohydrates. Total soluble solids increased from 9.1 °Brix (initial) to 13.7 °Brix (climacteric maximum) during maturation, while the total number of acids in the fruit decreased during maturation i.e. from 1.55% initially to 1.40% at pre-climacteric, 1.0% at climacteric maximum and 0.8% in the post-climacteric stage. A similar behaviour was observed in the case of ascorbic acid. There was a continuous decrease in chlorophyll and a continuous increase in the carotenoid content of fruit during maturation.