Increase In Osmotic Concentration Research Articles

Effect of Osmo Dehydration on Quality Attributes of Bilimbi (Averroha bilimbi) Fruits

Background: Bilimbi is a profusely bearing tree and majority of fruits produced are wasted due to lack of proper preservation methods. Osmo-dehydration studies on quality attributes of bilimbi (Averroha bilimbi) was conducted with the objective to standardize the process variables for osmodehydrated bilimbi and to assess the retention of bioactive compounds. Methods: Harvested mature bilimbi fruits of uniform size were washed, surface dried, pricked and blanched in hot water for one minute. Blanched fruits were subjected to osmotic treatment, with sucrose solution of 40, 60 and 80°B for 60, 120 and 180 minutes. The osmodehydrated bilimbi fruits were analyzed for mass transfer, biochemical and sensory qualities. Best treatments were stored for four months in the room temperature. Result: Mass transfer characters viz., solid gain, water loss, percentage weight reduction, yield and biochemical parameters such as reducing sugar and total sugar increased with increase in osmotic concentration and immersion time whereas free acids, ascorbic acid and antioxidant activity were decreased. The osmotic treatment of 80°B for 180 minutes recorded the highest value for solid gain (5.10%), water loss (16.72%), weight reduction (22.57%), ratio of water loss to solid gain (3.25%) and yield (21.13%) which exhibited superior sensory scores for taste (8.43), flavor (8.27), texture (8.46) and overall acceptability (8.43). The best three treatments selected based on sensory analysis were subjected to storage stability studies under room temperature. Osmodehydrated bilimbi obtained highest sensory score at the end of storage.

In vitromodelling of salinity stress for the selection of stress-tolerant birch lines

This paper examines the salinity stress effectin vitroculture of microshoots of 10 birch clones:Betula pendulaL.,B. pendulaRoth var.carelica(Mercklin) Hämet-Ahti,B. pendulaf. ’dalecarlica’(L.f.) Schneid.,B. pubescensEhrh. We used economically valuable and genetically diverse (various species, varieties, hybrids, polyploids) birch material fromin vitroclone collection. We tested 3in vitroselection methods on 1/2 MS hormone-free nutrient medium: mild – with a prolonged exposure to 0.2% NaCl; gradual – with a step-by-step increase in osmotic concentration (from 0.2% to 1%); severe – with a sublethal (1%) NaCl concentration. We established that the gradual method of NaCl exposure according to the following pattern: 0.2% → 0% → 0.5% → 0% → 0.75% → 0% → 1.0% resulted in the best selective effect for birch, as it provides a clear differentiation of clones in terms of their salinity tolerance. We identified that the genotype had a significant impact on the preservation of the explants and their ability to regenerate under salinity stress. The study showed that tetraploid clones of downy birch and a triploid clone of Karelian birch of a pronounced mixoploid nature had the greatest salinity tolerance.

Mechanisms of regulation of erythrocyte volume in common carp Cyprinus carpio (Cyprinidae) at increase in the osmotic concentration of blood plasma within the zone of critical water salinity

In common carp Cyprinus carpio, acclimated to NaCl content in water of 0–6 g/L, the concentration of sodium in blood plasma was relatively constant (130.8 ± 0.7 mM/L). In the fish acclimated to 6−12 g/L NaCl, which corresponds to critical water salinity, plasma sodium content rose to the maximal value of 205.6 ± 1.3 mM/L. Within the interval of water salinity of 0–6 g/L NaCl, the content of potassium in erythrocytes exhibits a trend to gradual decrease from 104.8 ± 1.6 mM/L to 96 ± 1.5 mM/L. In the zone of critical salinity, potassium content increases exponentially to 130.3 ± 2.9 mM/L. The erythrocytes adapted to the increase in osmotic concentration of plasma by accumulation of potassium ions. According to published data on the studies in vitro, the erythrocytes adapt to hypertonic solutions by means of increase in intracellular sodium concentration. Possible reasons for discrepancy between the results of in vivo and in vitro studies are discussed in the present paper.

Involvement of Interstitial Structures of the Kidney into Hydrosmotic Effect of Vasopressin (Morphofunctional Study)

Administration of desmopressin for 4 days to homozygous Brattleboro rats lacking endogenous vasopressin induced an increase in osmotic concentration and was accompanied by typical changes in the morphofunctional state of interstitial cells of the renal papilla. These changes increase the permeability of extracellular matrix, which attested to the involvement of interstitial cells into hydrosmotic reaction to vasopressin.

Influence of Drought on Mitochondrial Activity, Photosynthesis, Nocturnal Acid Accumulation and Water Relations in the CAM Plants Prenia sladeniana(ME-type) and Crassula lycopodioides(PEPCK-type)

The activity of photosynthesis and mitochondrial respiration, nocturnal organic acid accumulation and water relations were investigated in Prenia sladeniana L. Bol. [malic enzyme (ME)-type] andCrassula lycopodioides Lam. [phosphoenolpyruvate carboxykinase (PEPCK)-type] to compare the physiological responses to water deficit in crassulacean acid metabolism (CAM) plants differing in their decarboxylating enzyme systems. Withholding water inhibited daytime gas exchange within 2d while night time CO2gain and malic acid accumulation remained relatively unchanged in both species. In P. sladeniana, maximum photochemical efficiency (Fv/Fm) and photosynthetic electron transport declined to nearly the same degree as CO2supply was restricted during drought. Despite limited CO2availability, photosynthetic activity was largely unaffected in C. lycopodioides, as were mitochondrial properties. There is no indication of a drought-induced increase in the capability to totally oxidize malate, yielding 4 CO2, in either species. Nevertheless, the enhanced ratio of malate to glycine oxidation may have increased the in vivo capability for malate oxidation in P. sladeniana. Although pressure potential was maintained throughout the experiment in both species, active osmotic adaptation occurred only inP. sladeniana. The observed decrease in photosynthetic and mitochondrial activity may have resulted from the large increase in osmotic concentration in this species.

Volume regulation in three species of marine mussels

Three species of marine mussels were acclimated to the following range of osmotic concentrations: Modiolus modiolus L., 718–1000 mOsm; Mytilus edulis L., 375–980 mOsm; Geukensia demissa Dillwyn, 298–900 mOsm. Changes in the relative weight of whole animals, or changes in tissue water, extracellular water, and intracellular water of the posterior adductor muscle were measured in mussels acclimated to the different osmotic concentrations. These parameters were regressed against the reciprocal of relative osmotic concentration (1/ROC). The slopes of the regression lines were used to estimate the capacity for volume regulation: the larger the slope the lower the capacity. The relative weight of Modiolus acclimated to different osmotic concentrations changed significantly, indicating imperfect volume regulation, but no such change occurred in either Mytilus or Geukensia, indicating perfect volume regulation. For both tissue water and intracellular water, the slopes of the regression lines indicated that the capacity for volume regulation followed the sequence: Geukensia = Mytilus> Modiolus. Extracellular water decreased with an increase in osmotic concentration in Modiolus, but was constant in both Mytilus and Geukensia. The ratio of intracellular water to total tissue water followed the sequence Modiolus > Mytilus > Geukensia.

Osmoregulation in the Avena Coleoptile

Peeled Avena sativa coleoptile sections (i.e. sections from which the epidermis has been removed) have been used to study the control of solute uptake under conditions where the uptake is not limited by the cuticular barrier. In the presence of 2% sucrose, auxin enhances the rate at which the total osmotic solutes increase, but this appears to be a response to the increased growth rate, inasmuch as the auxin effect is eliminated when growth is inhibited osmotically. When sections are incubated in sucrose or in 20 millimolar NaCl, the osmotic concentration increases until a plateau is reached after 8 to 24 hours. Auxin has no effect on the initial rate of increase in osmotic concentration but causes the osmotic concentration to reach a plateau earlier and at a lower osmotic conentration value. This difference in steady-state osmotic concentration is, in part, a response to auxin itself, as it persists when auxin-induced growth is inhibited osmotically. The upper limit for osmotic concentration does not appear to be determined by the turgor pressure, inasmuch as a combination of sucrose and NaCl gave a higher plateau osmotic concentration than did either solute alone. We suggest that the rate of solute uptake is determined by the availability of absorbable solutes and by the surface area exposed to the solutes. Each absorbable solute reaches a maximum internal concentration independent of other absorbable solutes; the steady-state osmotic concentration is simply the sum of these individual internal concentrations.

Osmoregulation in Blaberus craniifer after parenteral injections of NaCl solutions

1. 1. After injection of NaCl into the abdominal hemocoel of Blaberus craniifer, the osmotic concentration of antennal hemolymph peaked at 1.25hr and returned to pre-injection concentration by 21 hr. The mean plasma clearance was 2.67 μl/hr. 2. 2. Force-feeding of water 15min after injection of NaCl prevented the early rise in hemolymph osmotic concentration, but a later gradual increase in osmotic concentration occurred. 3. 3. The onset of spontaneous drinking occurred 0.8 hr after NaCl injection; this correlated with an elevation in hemolymph osmotic concentration. 4. 4. Cumulative spontaneous water intake over 4 days was proportional to the daily injected dose of NaCl.

温州ミカンの着果負担に関する研究 (第1報)

Diurnal and seasonal fluctuations in osmotic concentration in leaves and shoots of alternate- and annual-bearing satsuma mandarin trees were examined to test whether or not these changes are correlated to the internal moisture status. The following observations were made:1) Osmotic values of leaves and shoots increased during the day attaining a maximum about 2-4PM and subsequently decreased to a minimum at 6AM. This diurnal pattern did not vary among the different seasons. Analysis of seasonal samples taken once a month at 10AM revealed that the osmotic values were relatively low in mid-summer and high during the months of January and February. The osmotic values increased beyond the degree of the decrease in water contents in winter. It was also confirmed from these data that the change of osmotic values in winter was due not only to that of the water contents but also to that of the solute ratios.2) Calculations of the solute ratio by the following equation:Solute ratio=osmotic value (atm)×% moisture content/24.05, the constant 24.05=the osmotic value of a molal solution, disclosed that the values of leaves and shoots closely paralleled the water contents in the organs from spring to summer and corresponded to osmotic concentrations of them from autumn to winter. Changes in solute ratios of leaves and stems occasionally oscillated as much as I mol which was comparable to the maximum amplitude of their diurnal fluctuations found in the organs.3) The presence of fruits influenced the osmotic values of the sap extracted from leaves and shoots. The osmotic values of leaves and stems in non-bearing 4-year-old trees were respectively higher in almost every season as compared to those of correspondingly aged organs in the bearing trees.4) As for alternate bearing mature trees in the on-year, osmotic concentration of 1-year-old leaves was relatively low during the period from June to September, increasing markedly after harvest. From autumn to winter, however, two-year-old leaves and shoots of heavily cropped trees did not show an increase in osmotic concentration which comparable organs from trees with a light or no crop manifested at the same period.

Mechanism of Apothecial Opening and Ascospore Expulsion by the Cup-Fungus Urnula Craterium

SummaryThe apothecial wall of the cup-fungus Urnula craterium consists of three layers, an outer black, non-elastic, leathery one, a nearly colorless, gelatinous, water-holding, medullary one, and an inner brown hymenial one.The apothecia open as the result of pressure exerted by the paraphyses, which on swelling are changed from branched septate filaments to bead-like chains of ellipsoidal cells. This change is confined to a zone at the rim. Swelling results from increase in osmotic concentration, a consequence of the transformation of reserve glycogen in the hymenial layer to reducing sugar. Apparently melanin in the outer apothecial wall functions to absorb heat to the extent of initiating the activity of the glycolytic enzyme system. Essential moisture is supplied by the medullary layer.The apices of the asci are turned upward, a phototropic response.This mechanism for opening the cup to expose the hymenium is presently known to occur only in Urnula craterium and U. Geaster.Addendum—Mycelial cultures of Urnula craterium originating from ascospores were planted on decaying branches of oak that had been sterilized. After approximately 6 months, black heaps of conidia had formed. This conidial stage appears to be Strumella corynoidea Sacc. and Wint., which Davidson (Mycologia 42: 735–742. 1950) suspected of being the conidial stage of Urnula craterium.