The effect of growing system on the storability of apple

The effect of organic growing was studied on the storability of apple cv. Jonica, Liberty, Mutsuand Pinova. Fruits from integrated and organic orchards were stored at 2-4 °C, 95-99% relative humidity for 6 months. Firmness, activity of b-galactosidase and polygalacturonase enzymes were examined. There was no difference in the activity of β-galactosidase and polygalacturonase enzymes at harvest between the organic and integrated apples, but a significant difference was noted between the cultivars except for Mutsu and Pinova. The activity of b-galactosidase enzyme increased significantly during storage except for cv. Pinova and that of polygalacturonase enzyme also increased significantly. The difference in the activity of polygalacturonase became significant between the cultivars during storage except for cv. Jonica and Pinova. The firmness decreased significantly during storage, with the least change in case of cv. Liberty. It can be established that there is, in general, neither a considerable difference between the growing systems nor between varieties at harvest. The differences became higher during storage. It can be stated that the effect of cultivar on the storability is much more considerable than the effect of growing system

Changes in flavour, cell wall degrading enzymes and ultrastructure of guava (Psidium guajava L.) during ripening

Volatile flavour substances were isolated from the minced pulp of half ripe and full ripe fruits of guava (Psidium guajava L.) cv. Lucknow-49 by simultaneous steam distillation extraction (SDE) with diethyl ether as extracting solvent. The concentrate was analysed by GC-MS. Acetic, butyric and hexanoic acids were the predominant acids, trans-2-hexenal and hexanal the predominant aldehydes and ethyl propanoate, methyl butyrate, ethyl butyrate, methyl hexanoate, ethyl hexanoate, cis-3-hexen-1-yl acetate, hexyl acetate, methyl benzoate, methyl octanoate, ethyl benzoate, phenylpropyl acetate and cinnamyl acetate, the esters responsible for the characteristic guava flavour were also present. The amount of total volatile substances was about 20% higher in full ripe fruits. The concentration of acids and most esters increased and that of C6 aldehydes decreased during ripening. The enzyme analysis showed that the polygalacturonase (PG) activity was lower in the ripe fruit, than in the half ripe one, while the β -galactosidase activity was not influenced by maturity stage. The surface and the cell walls of full ripe guava became wrinkled, and parenchyma cells were empty (SEM)

Physiological and ultrastructural changes in ber ( Zizyphus mauritiana Lamk.) fruits during ripening

Colour (L*, a*, b*, ho and chroma), β-galactosidase, polygalacturonase (PG) activity, pectin content, ultrastructure and volatile compounds were determined, in mature green and in yellow ber fruits ( Zizyphus mauritiana Lamk. cv. Umran).The L* did not, but a*, b* and ho significantly differed between mature green and yellow ber fruit. The pectin content and its solubilization (soluble pectin and neutral sugars), the activity of PG was higher in yellow ber fruits and in the outer part of fruits. Activity of β-galactosidase was higher in mature green ber fruits. The cell walls of mature green fruits were usually homogeneous, the density of the middle lamellae decreased in yellow bers, and at the same time, the structure of chloroplastids disintegrated. The aroma of yellow ber is characterized by the presence of even carbon number of ethyl esters from C4 to C14

Yield and fruit quality of apple from conventional and organic production systems Rendimento e qualidade de maçãs em pomares conduzidos nos sistemas convencional e orgânico de produção

The objective of this study was to assess the yield and fruit quality of apple produced with a conventional and an organic production systems in Southern Brazil. The orchards consisted of alternate rows from 10 to 12-year old 'Royal Gala' and 'Fuji' apple trees on M.7 rootstocks, grown as slender spindles, on 4x6 m spacing. Eighteen apple trees of each cultivar and management system were randomly selected and assessed for nutrition, flowering, fruit set, yield, and fruit quality during two growing seasons (2002/2003 and 2003/2004). The organic management system resulted in lower concentrations of K, Mg, and N in leaves and fruits, and in smaller fruits for both cultivars, and lower fruit yield for 'Fuji' than from the conventional production system. For both cultivars, fruits from the organic orchard harvested at commercial maturity had a more yellowish skin background color, higher percentage of blush in the fruit skin, higher soluble solids content, higher density, higher flesh firmness, and higher severity of russet than fruits from the conventional orchard. Fruit from the organic orchard had lower titratable acidity in 'Royal Gala', and higher incidence of moldy core and lower incidence of watercore in 'Fuji', than fruit from the conventional orchard. A non-trained sensory panel detected no significant differences for fruit attributes of taste, flavor and texture between fruit from the production systems for either cultivar.<br>O objetivo deste estudo foi avaliar o rendimento e a qualidade de frutos em pomares de macieira, nos sistemas convencional e orgânico de produção no Sul do Brasil. Os pomares consistiram de filas alternadas de plantas com 10 a 12 anos de idade das cultivares Royal Gala e Fuji, sobre porta-enxerto M.7, conduzidas com líder central, em espaçamento de 4x6 m. Dezoito plantas de cada cultivar e sistema de manejo foram marcadas aleatoriamente e avaliadas quanto à nutrição, floração, frutificação efetiva, rendimento e qualidade de frutos, em dois anos agrícolas (2002/2003 e 2003/2004). O sistema orgânico apresentou menores concentrações de K, Mg e N nas folhas e frutos, frutos de menor tamanho em ambas as cultivares e menor rendimento de frutos na cultivar Fuji. Em ambas as cultivares, frutos do pomar orgânico na maturação comercial apresentaram cor de fundo da casca mais amarelada, maior percentagem de coloração vermelha, maior teor de sólidos solúveis totais, maior densidade, maior firmeza de polpa e maior severidade de "russet" do que frutos do pomar convencional. No pomar orgânico, 'Royal Gala' apresentou a menor acidez titulável e 'Fuji' a maior incidência de podridão carpelar e menor incidência de pingo-de-mel. Não foram detectadas diferenças significativas quanto ao sabor, aroma e textura dos frutos entre sistemas de produção, em ambas as cultivares