Maria Izabel Gallão

Ultrasound-Assisted Osmotic Dehydration of Strawberries: Effect of Pretreatment Time and Ultrasonic Frequency

Pretreatment of fruits prior to drying has shown success in reducing drying time and costs. In this work, ultrasound-assisted osmotic dehydration has been implemented as a method to increase water diffusivity and reduce drying time in strawberries. Strawberry halves were immersed in distilled water and in two different concentrations of sucrose solutions while pretreatment time and ultrasonic frequency levels were varied to determine their effect on drying time, water loss, and soluble solids gain. A microscopic analysis was carried out to evaluate the formation of microchannels and other changes to the fruit tissue structure. Greater sucrose concentration used in ultrasound-assisted osmotic dehydration resulted in greater water loss with greatest loss observed for the strawberry halves pretreated for 45 min in a 50% w/w sucrose solution. The pretreatment carried out for 30 min employing an osmotic solution of 50% w/w of sucrose resulted in the highest drying rate among the pretreatments. Osmotic dehydration used alone during pretreatment increased total processing time, whereas osmotic dehydration combined with ultrasonic energy during pretreatment reduced total processing time and increased effective water diffusivity. Cell distortion and breakdown were observed not only in pretreatments employing ultrasound-assisted osmotic dehydration but in conventional osmotic dehydration. Formation of microchannels through ultrasonic application and effects of osmotic pressure differential were considered to be largely responsible for reducing drying time for strawberry halves.

Effect of Immersion Time in Osmosis and Ultrasound on Papaya Cell Structure during Dehydration

The effect of ultrasound-assisted osmotic dehydration applied at atmospheric pressure for different lengths of time on papaya tissue structure was evaluated. Ultrasound induced the loss of cellular adhesion, formation of large cell interspaces, and light rupture of the cell walls. The changes in the tissue structure caused by ultrasound application increased sugar loss, water loss, and effective water diffusivity. Ultrasound-assisted osmotic dehydration induced a gradual distortion in the shape of the cells, loss of cellular adhesion, and the formation of large channels caused by rupture of the cell walls. The changes caused by the application of osmotic dehydration resulted in high water loss and sugar gain.

Caracterização da germinação e morfologia de frutos, sementes e plântulas de Dalbergia cearensis Ducke (pau-violeta) - Fabaceae

This study describes and illustrates the morphological characteristics of fruits, seeds, early stages of germination and seedlings of Dalbergia cearensis for the first 28 days after sowing. The fruit, which is supported by a 3-5 mm stipe, is a dry, indehiscent samara, oblong with acute base and apex, 1-seeded, flat, with a central seminiferous nucleus, thin pericarp, aliform, slightly reticulate. The seed is exalbuminous, oblong, flat, reniform, with a smooth seed coat; it is a brownish color when ripe. Germination is epigeous, with the tegument adhering to the cotyledons in the initial seedling growth phase; it begins on the third day after sowing in laboratory conditions. Mean germination of 70% was observed at 14 days. On day 28 after sowing, seedlings had an axial root system, a pivotal main root, 231.54 mm long, cylindrical, flexible, yellowish-white. The seedlings are classified as phanero-epigeal-reserve (PER) type.

Morfologia de sementes e plântulas de cártamos

The safflower (Carthamus tinctorius L.) belongs to the Compositae or Asteraceae family, nowadays, it is used to adornment. The objective of this experiment was to determinate the biometry, to describe and to illustrate the external morphology of the seed. The essay was conducted at the Laboratory of Analysis of Seeds of the Phytotechny Department, Center of Agricultural Sciences of the Federal University of Ceara State. It was calculated the weight of 1000-seeds and the water content of the seeds. It was made the individual measuring of the length, of the breadth and of the thickness to the biometric determinations and determined the morphologic characterization of their external parts. The 1000-seeds weight of this lot was 33.75 g and the water content was 8.6%. It was observed that the safflower seed is eurispermic, with the following dimensions: length equal to 6.84 mm, width equal to 4.21 mm and thickness equal to 3.37 mm. The germination is phanero-epigeal.

Mobilisation of reserves during germination of Jatropha seeds

Phanerogam species reserve nutrients in their seeds in order to sustain propagation. Their chemical composition and the way the metabolites are used vary, according to genotype, the environment and the interaction between these factors. As the jatropha is considered a strategic oilseed crop in biofuel production, the aim of this work was to quantify the major reserve components (starch, protein, soluble sugar and lipid) of the jatropha seed and its disposition in the cells during different periods of germination, in order to understand the process of reserve mobilisation and to determine the potentially right time for the extraction of vegetable oil for that species. The seeds were soaked in water for 0; 12; 24; 36; 42; 45 and 48 hours, following a completely randomised design and evaluated for wet and dry biomass, chemical characteristics of the reserves and the disposition of the reserve compounds. Through research, it was observed that the levels of lipids increased up to 43% at the moment of protrusion. The carbohydrate levels, in both the endosperm and the embryo are minimal during protrusion and shortly after, indicating the maximum use of carbohydrates in the germination process. Greatest protein synthesis occurs with the greatest moisture gain, with a reduction in and agglomeration of protein bodies during embryo root growth after protrusion. Despite the presence of starch in the endosperm of jatropha curcas L., starch cannot be considered a source of sugars during the period of germination studied.

Ultrastructural and biochemical changes induced by salt stress in Jatropha curcas seeds during germination and seedling development.

Jatropha curcas L. is a multipurpose species of the Euphorbiaceae family that is widespread in arid and semiarid regions. This study investigated the ultrastructural and biochemical changes induced by salt stress during J. curcas seed germination and seedling development. Salt stress negatively affected seed germination and increased Na+ and Cl- contents in endosperms and embryo-axis. Lipids represented the most abundant reserves (64% of the quiescent seed dry mass), and their levels were strongly decreased at 8 days after imbibition (DAI) under salinity stress. Proteins were the second most important reserve (21.3%), and their levels were also reduced under salt stress conditions. Starch showed a transient increase at 5 DAI under control conditions, which was correlated with intense lipid mobilisation during this period. Non-reducing sugars and free amino acids were increased in control seeds compared with quiescent seeds, whereas under the salt-stress conditions, minimal changes were observed. In addition, cytochemical and ultrastructural analyses confirmed greater alterations in the cellular reserves of seeds that had been germinated under NaCl stress conditions. Salt stress promoted delays in protein and lipid mobilisation and induced ultrastructural changes in salt-stressed endosperm cells, consistent with delayed protein and oil body degradation.

Avaliação citoquímica durante a germinação de sementes de sorgo envelhecidas artificialmente e osmocondicionadas, sob salinidade

The aim of this study was to evaluate the rate of water absorption and cytochemical changes in primed and aged seeds of sorghum during germination under absence or presence of 100 mM NaCl. The initial batch of seeds of sorghum cv. IPA-1011, was divided into two batches of different levels of vigor, by the accelerated aging of half seeds, with half of each batch also referred to the priming of polyethylene glycol 6000 at -0.86 MPa for 48 hours. Four replicates of 50 seeds from each batch were placed on two sheets of filter paper, blotting paper saturated with distilled water and placed inside gerboxes (11 x 11 x 3.5 cm) transparent lids, which were kept in a germination chamber under continuous darkness and 25 oC for 72 hours. The cytochemical analysis characterization was measured in the soaking times of 0; 24; 48 and 72 hours. The sorghum seeds cells showed irregular shapes, ranging from elliptical to rounded, and the staining with the toluidine blue also revealed the presence of nuclei, especially in primed seeds, indicating that some cells showed high cellular activity. The presence of protein was detected mainly in protein bodies on cytoplasm of cotyledon cells, while the starch was identified in the form of granules at endosperm. The accelerated aging treatments and seed priming, associated to salt stress resulted in little morphological and cytochemical visible changes during the experimental period analyzed.

Response to chitin in suspension-cultured Citrus aurantium cells

Morphological changes and enzyme activity in suspension-cultured cells of Citrus aurantium were followed after chitin elicitation. Chitin oligomers presented a rapid effect with a maximum activity after 3 h followed by a gradual decrease to the original levels at 8 h of incubation. Cell walls presented a lignification process and the cytoplasmatic protein became less reactive to anionic stains. In the treated material a reduction in starch grain size, an increase in the number of autophagic vacuoles, deposition of secretion in the pericellular space and a defibrillation of the cell-wall polymers were observed. Chitin oligomers increased peroxidase and L-phenylalanine ammonia-lyase activities. Extracellular peroxidase activity increased from 0.20 U mL-1 after 1 h to 0.45 U mL-1 at 3 h followed by a gradual decrease up to 8 h. The peroxidase isoenzyme pattern revealed a predominance of basic isoenzymes in these cells.

Fenologia de Dalbergia cearensis Ducke (Fabaceae) em um fragmento de floresta estacional, no semiárido do Nordeste, Brasil

In general, tree species that occur in the Caatinga vegetation in the Brazilian semiarid of the northeastern region, have their phenophases (flowering, fruiting and foliage change) conditioned by the duration and intensity of seasonal drought. This study records the phenology of leaf-fall, leaf incision, flowering and fruit production of 32 Dalbergia cearensis Ducke individuals. Samples were collected every 15 days from 2009 to 2011 at the Unidade de Conservacao de Uso Sustentavel Fazenda Nao me Deixes, a conservation area in the Brazilian semiarid. The frequency of occurrence of the phenophases was related to the elements of climate (average monthly rainfall, monthly average temperature, monthly average insolation and soil water availability). The vegetative phenology, leaf fall and sprouting of new leaves, followed the seasonality of rainfall during the dry and rainy seasons. The flowering and fruiting occurred at the beginning of the rains, and the diaspores of D. cearensis were scattered throughout the year after they broke off slowly from the compact axillary panicles.

Effects of industrial cashew nut processing on anacardic acid content and allergen recognition by IgE

Cashew nuts are important both nutritionally and industrially, but can also cause food allergies in some individuals. The present study aimed to assess the effect(s) of industrial processing on anacardic acids and allergens present in cashew nuts. Sample analyses were performed using liquid chromatography coupled with mass spectrometry, SDS-PAGE and immunoassay. The anacardic acid concentration ranged from 6.2 to 82.6mg/g during processing, and this variation was attributed to cashew nut shell liquid incorporation during storage and humidification. Dehydrated and selected samples did not significantly differ in anacardic acid content, having values similar to the raw sample. SDS-PAGE and immunoassay analysis with rabbit polyclonal sera and human IgE indicated only minor differences in protein solubility and antibody binding following processing steps. The findings indicate that appreciable amounts of anacardic acid remain in processed nuts, and that changes to cashew allergens during industrial processing may only mildly affect antibody recognition.