Final Dry Matter Content Research Articles

Hydraulic, morphological, and anatomical changes over the development of cotton bolls and pedicels leading to boll opening under well-watered and water deficit conditions

The growth, development, and opening of cotton bolls largely determine the yield and quality of cotton plants. However, the hydraulic, morphological and anatomical changes of cotton bolls over this course are unclear. This study investigated the hydraulic properties, xylem structure and function of the cotton boll and the pedicel, and the boll transpiration over the developmental course of bolls under well-watered and water deficit conditions based on hydraulic measurements, dye tracing, boll water uptake, and microscopy. Results revealed that xylem structure and function of the boll and the pedicel were well maintained and bolls had a high transpiration rate during boll dehydration period under both conditions. Water deficit significantly reduced boll number, had no significant effect on the final dry matter content of bolls, and had limited effects on boll transpiration and hydraulic properties of the boll and the pedicel. This study indicates that vascular transport between the parent plant and the boll and boll transpiration were well coupled to ensure dry matter accumulation in the boll and promote boll dehydration.

Modeling the Effects of Osmotic Dehydration Pretreatment Parameters and Lyophilization Kinetics on Mass Transfer and Selected Nutritive Parameters of Peaches

The effects of the osmodehydration pretreatment parameters on successive lyophilization mass transfer kinetics of the peaches, dehydrated in the combined dehydration process, were investigated and mathematically modelled. The obtained results showed the statistically significant effect of osmotic dehydration pretreatment and its parameters on the final dry matter content and water activity values of the dehydrated peaches. The maximum dry matter content and minimal water activity values of dehydrated peach samples were 84.60 % and 0.423, respectively, produced in osmodehydration pretreatment in molasses of 80 % concentration, at 50 °C, during a 5-hour process and subsequent 6-hour lyophilization. With the increase of all osmodehydration pretreatment parameters it is possible to reduce the duration of the lyophilization process, reducing the high energy demand of the dehydration method (lyophilization) and substituting it with low energy demanding dehydration method (osmodehydration) without compromising the quality of the final product, regarding the dry matter content and water activity values. Mathematical models describing the effect of the duration of the lyophilization on the dry matter content and water activity values of the fresh and dehydrated peaches were developed. They showed a good correlation between calculated and experimental values, allowing a good prediction of the investigated responses. In the combined method, protein, sugar, K and Fe content of the dehydrated peach samples were enriched and further enhanced in prolonged lyophilization stages.

Fractionation methods affect the gelling properties of pea proteins in emulsion-filled gels

Plant proteins, after extraction from sources such as pea can be used as functional ingredients in emulsions and gels. However, the protein fractionation route used affects the protein functionality. We investigated the differences in rheological properties of emulsion-filled gel (EFGs) structured by pea protein isolate obtained using either isoelectric precipitation (PPIp) or diafiltration (PPId), at varying pH and oil content. PPIp and PPId had a protein content of 75.3 and 77.7 wt %, respectively. We first studied the oil-water interfacial rheology and composition in emulsions, as these interfacial and emulsion properties can influence EFG properties. Both PPIp and PPId formed a viscoelastic, soft-solid protein layer around the oil droplets and both PPIs were able to stabilize emulsions with monomodal droplet size between 1 and 10 μm. Additional pea protein was added to the emulsions to achieve a final protein dry matter content of 15 wt % and gelling was induced by heating the protein-enriched emulsion in the rheometer to 95 °C. At pH 5, PPIp and PPId formed EFGs with comparable firmness (i.e. similar G’) and with a heterogeneous microstructure. At pH 7, PPIp formed less firm and homogeneous gels compared to PPId. The difference was related to protein solubility and aggregation, caused by different fractionation methods. In the EFGs, the presence of oil droplets did not reinforce the gel structure, which could be explained by weak interactions between the oil droplet interface and protein matrix. Our results show that pea protein fractionation routes affect the properties of PPI gels and EFGs. These insights may contribute to pea protein fractionation that is tailored to specific structural requirements for gel-based foods.

Dewatering and Mineralization of Sludge in Vertical Flow Constructed Wetlands: A Review

Sludge treatment in vertical flow constructed wetlands (VFCWs) is a promising alternative to conventional treatment, which provides adequate treatment at low-cost, while being energy efficient. They may dewater and mineralize various kinds of sludge, including surplus sludge from activated sludge systems, agricultural slurries, and septage and faecal sludge effectively. This paper presents a review of the state-of-the-art of VFCWs treating sludge. The effects of varying design and operational parameters, as well as environmental factors on treatment performance are discussed. The paper also summarizes the performance of various pilot- and full-scale systems in terms of final dry matter content and degree of mineralization. In order to understand the governing processes and predict its performance, modelling of VFCWs in sludge treatment is suggested.

Influence of Coating Application Methods on the Postharvest Quality of Cassava.

Various modes of edible coating application vary in their coat dispersion and film formation, hence the need to determine the most effective mode of application for cassava. Edible surface coatings have been found to be effective in preserving the quality of various food products. However, there are variations in effectiveness among the different coating solutions, hence the need for optimization of the concentrations of the gums used. This study aimed at determining the most efficient coating application method on the cassava postharvest quality. Physiologically mature cassava (variety KME 1) was harvested and divided into seven portions. The various portions were coated using 1.5% xanthan gum, 1.5% xanthan/guar gum, and 2% xanthan/guar gum by both dipping and spraying method. There was no significant difference on the colour, total cyanide, ethylene production, and total phenolic content between the two application methods. The 2% xanthan/guar gum coating showed a significant difference on the dry matter content while the 1.5% xanthan gum coating had a significant difference on the respiration rate and weight loss. The 1.5 xanthan treated roots had a final dry matter content of 72.5% for the sprayed samples and 75.98% for the dipped sample while the 2% xanthan/guar gum treated roots had a final dry matter content of 64.6% and 74.1% for the dipped and sprayed root samples, respectively. The 1.5% xanthan and 2% xanthan/guar gum treated roots showed no significant difference in their action on dry matter content. The 1.5% xanthan/guar dipped and sprayed samples differed significantly on their effect on flesh firmness with final values of 35.4N and 46.1N, respectively, at 20 days after harvest. This study suggested that based on the coating solution and the parameters being observed, there generally was no varying effect of dipping and spraying methods of coating application. The choice of the efficient mode of application to use will depend on other factors such as the easiness of application.

Sludge Dewatering and Mineralization in Sludge Treatment Reed Beds

Sludge Treatment Reed Beds (STRBs) are widely used in Northern Europe to dewater and mineralize surplus sludge from activated sludge systems used to treat urban domestic sewage. STRBs are low-technology, energy-efficient, and do not require addition of chemicals. They dewater and stabilize the sludge and produce a final product that can be safely used as a fertilizer for agricultural crops. Long-term sludge reduction takes place in the reed beds due to dewatering and mineralization of the organic matter in the sludge. Although, in theory, a simple technique relying largely on natural processes, experience has shown that it is very important to understand and respect the basic design and operation requirements of STRBs. This paper describes the basic design and operation requirements of STRBs, with special focus on pivotal requirements to respect in order to secure proper functioning. Also, the paper summarizes performance experience concerning final dry matter content, degree of mineralization, emission of greenhouse gases, and degradation of micro-pollutants in STRBs. There are still a number of outstanding issues that are not fully understood, particularly in relation to the importance of the sludge quality for the dewatering in an STRB. Therefore, extreme care should be taken when attempting to extrapolate the use of STRBs to applications and regions outside of their ‘normal’ and documented area of application.

Dewatering treatments to increase dry matter content of the brown seaweed, kelp (Laminaria digitata ((Hudson) JV Lamouroux))

Macroalgal water content is an on-going problem for the use of readily accessible seaweeds in sustainable biorefining, including fuel production. Silage is a reduced-water, compactable, easily stored, transportable material. Ensiling could establish a non-seasonal supply of preserved algal biomass, but requires high initial dry matter content to mitigate environmental pollution risks from effluent. This study investigated potential dewatering methods for kelp harvested throughout the year. Treatments included air-drying, osmotic media and acids. Significant interactions between treatment and harvest-time were observed for traits of interest. Fresh weight loss during treatment was composed of changes in water and dry matter content. Air-drying gave reliable increase in final dry matter content; in summer and autumn 30% dry matter content was reached after 24h. Dilute hydrochloric acid reduced stickiness and rendered material suitable for dewatering by screw-pressing; it may be possible to use the consequent pH reduction to promote efficient preservation.

Batch-based enzymatic saccharification of sweet sorghum bagasse

ABSTRACTTo improve enzymatic digestibility and sugar concentration, sweet sorghum bagasse was pretreated with alkali and liquid hot water, and then subjected to fed-batch enzymatic hydrolysis. Scanning electron microscopy assay suggested that different pretreatment methods resulted in different composition and structure of residues; these changes had a significant influence on cellulose hydrolysis. Fresh substrate was pretreated and then added at different amounts during the first 48 h to yield a final dry matter content of 30% (w/v). For liquid hot water pretreatment, a maximal glucose concentration of 95.71 g/L, corresponding to 52.85% xylan removal, was obtained with the sweet sorghum bagasse pretreated at 184°C for 18 min. NaOH soaking at ambient conditions removed lignin up to 60%, and the subsequent hydrolysis with cellulase loading of less than 10 FPU/g DM, and substrate supplementation every few hours yield the high glucose and xylose concentrations of 114.89L and 29.93 g/L, respectively after 144 h.

Production of Pomegranate Juice Concentrate by Complete Block Cryoconcentration Process

AbstractIn this study, complete block cryoconcentration of pomegranate juice was investigated. Two freezing temperatures (−20 ± 1C and −40 ± 1C), two thawing modes (gravitational‐assisted thawing and microwave‐assisted thawing) and four cryoconcentration stages were the process variables. Total dry matter content, process efficiency, pH and color values (L, a, b and ΔE) of cryoconcentrated and ice fractions were investigated. In addition, pomegranate juice concentrate was produced by conventional thermal processes, namely evaporation by rotary vacuum evaporator and by heating at atmospheric pressure to compare the color values and pH of final cryoconcentrated pomegranate juice with those of thermally produced juice concentrates. Freezing temperature and thawing mode did not have any significant effect on the total dry matter content of cryoconcentrated and ice fractions as well as process efficiency, pH and the color values (P > 0.05). However, the results indicate that cryoconcentration stage had a significant effect on dry matter content, process efficiency and the color properties of both fractions (P > 0.05). The final dry matter content of pomegranate concentrate reached 34.20 ± 0.13% from the initial value of 17.16 ± 0.68%. The change in the pH of final cryoconcentrated pomegranate juice was less than the change in the pH of thermally produced juice concentrates. This study showed that the color characteristics of pomegranate juice were well preserved by complete block cryoconcentration process in comparison to conventional thermal processes.Practical ApplicationsConcentration of fruit juices is one of the oldest methods by which the shelf life of fresh products can be extended significantly. Concentration of fruit juices by means of thermal process is proved to induce adverse effects on sensory and chemical properties of them. Cryoconcentration technology is introduced as a suitable technique for concentration of liquid foods and nutraceuticals because it can preserve the nutritional and sensory qualities of the products while it is a green technology. Because pomegranate juice is a valuable source of bioactive compounds that are responsible for its appropriate color, cryoconcentration process has high potential for preserving its nutritional and sensory properties during concentration process.

Influence of light intensity on the rate of photosynthesis and dry matter accumulation in Oriental hybrid lily ‘Siberia’ at different developmental stages

SummaryWe investigated the effects of light intensity on various photosynthetic characteristics on a whole-plant (WP) basis, focussing on three developmental stages from leafing (when young leaves unfolded) to flowering in the Oriental hybrid lily ‘Siberia’. On a WP basis, the net photosynthetic rate (Pr) was low at the leafing stage, but increased rapidly at the visible flower bud and flowering stages. However, on a leaf area (LA) basis, plants at the leafing stage exhibited a high Pr, peaking at the visible flower bud stage and diminishing slightly at the flowering stage.The rapid increase in total LA due to plant growth and development had a strong influence on Pr on a WP basis. ‘Siberia’ plants were grown under various reduced levels of natural light (0%, 40%, or 60%), achieved by shading, to evaluate the contribution of photosynthetic assimilates at various developmental stages and to compare the consistency of these results with the photosynthetic characteristics of the plants. The final dry matter (DM) content on a WP basis was determined by the light intensity applied after the visible flower bud stage, but not before. These experiments indicated that, during the growth of ‘Siberia’ lily, photosynthesis determined DM accumulation after the visible flower bud stage. Low or high light intensities before or after this stage promoted stem elongation and leaf thickening, respectively. Therefore, shading during the early developmental stages and high sunlight during the later developmental stages were beneficial for the quality of Oriental hybrid lily cut flowers.

Ethanol Production from High Solids Loading of Alkali-Pretreated Sugarcane Bagasse with an SSF Process

A fed-batch process and high-temperature simultaneous saccharification and fermentation (SSF) process were investigated to obtain high sugar yield and ethanol concentration. Different amounts of alkali-pretreated sugarcane bagasse were added during the first 24 h. For the highest final dry matter (DM) content of 25% (w/v), a maximal glucose and total sugar concentration of 79.53 g/L and 135.39 g/L, respectively, were achieved with 8.3 FPU/g substrate after 120 h of hydrolysis. Based on the hydrolysis experiment, two processes for ethanol production from sugarcane bagasse, simultaneous saccharification and fermentation (SSF) and separate hydrolysis and fermentation (SHF), were also compared using S. cerevisiae. The results indicated that ethanol concentration and yield in the SHF were higher, while ethanol productivity (gram per unit volume and over time) was lower. For 25% substrate loading, the ethanol productivity and ethanol concentration could reach 0.38 g.L-1.h-1 and 36.25 g/L SSF in 96 h, respectively, while that of SHF could reach 0.32 g.L-1.h-1, with an ethanol concentration of 47.95 g/L in 152 h for SHF. When high-temperature simultaneous saccharification and fermentation (SSF) process was performed by using Kluyveromyces marxianus NCYC 587 at 42 °C, 42.21 g/L ethanol (with an ethanol productivity of 0.44 g.L-1.h-1) was produced with 25% dry matter content and 8.3 FPU cellulase/g substrate, which meant 16.4% more ethanol when compared with SSF of S. cerevisiae.

Artificial neural network model of pork meat cubes osmotic dehydratation

Mass transfer of pork meat cubes (M. triceps brachii), shaped as 1x1x1 cm, during osmotic dehydration (OD) and under atmospheric pressure was investigated in this paper. The effects of different parameters, such as concentration of sugar beet molasses (60-80%, w/w), temperature (20-50?C), and immersion time (1-5 h) in terms of water loss (WL), solid gain (SG), final dry matter content (DM), and water activity (aw), were investigated using experimental results. Five artificial neural network (ANN) models were developed for the prediction of WL, SG, DM, and aw in OD of pork meat cubes. These models were able to predict process outputs with coefficient of determination, r2, of 0.990 for SG, 0.985 for WL, 0.986 for aw, and 0.992 for DM compared to experimental measurements. The wide range of processing variables considered for the formulation of these models, and their easy implementation in a spreadsheet calculus make it very useful and practical for process design and control.

Osmotic dehydration of pork meat cubes: Response surface method analysis

The main objective was to examine the influence of different osmotic parameters on the mass transfer kinetics during osmotic treatment of pork meat (M. triceps brachii). The system?s response parameters observed were: water loss (WL), solid gain (SG), final dry matter content (DM) and water activity (aw). The optimum osmotic parameters seem to be: osmotic time of 4 h, molasses solution concentration of 72% and solution temperature of 45oC. These conditions were determined using Response Surface Methodology (RSM), and by superimposing the contour plots of each process variable. The predicted responses for the optimum drying conditions were: DM of 64.5%, WL in the close vicinity of 0.53, SG about 0.15 and aw in the range of 0.83 to 0.84.

High Temperature‐Induced Repression of the Rice Sucrose Transporter (OsSUT1) and Starch Synthesis‐Related Genes in Sink and Source Organs at Milky Ripening Stage Causes Chalky Grains

AbstractHigh temperatures during rice grain ripening reduced yield and grain quality. The proportion of milky white grains was 43.6 % at 30 °C but only 6.5 % at 25 °C. Grain filling was initially faster at 30 °C and finished earlier, and the final dry matter content was less, than at 25 °C. High temperature strongly suppressed the expression of the sucrose transporter gene OsSUT1 and starch synthesis‐related genes SuSy2, AGPS2b, BEIIb and Granule‐bound starch synthase in grains during early grain filling; the transcription levels of OsSUT1 at 14 days after flowering (DAF) were about 60 % lower in grains, flag leaf blade, flag leaf sheath and first leaf sheath. These facts are possibly involved in the earlier termination of grain filling at 21 DAF, following the rapid rise of grain dry weight from 0 to 7 DAF, due to possible reduction in assimilate supply via OsSUT1 under the high temperature. When panicles were partly clipped, the resultant increase in assimilate supply to the remaining grains significantly upregulated the expression of OsSUT1 and the starch synthesis‐related genes at 14 DAF, which consequently accelerated starch accumulation in the grains and ultimately increased the grain weight of remaining grains at 30 °C. These results indicate that high temperature during grain filling reduces grain yield and quality by changing the expression of OsSUT1 and starch synthase‐related genes, resulting in earlier ripening due to hastened or premature assimilate supply to grains.

Optimization of the osmotic dehydration of carrot cubes in sugar beet molasses

A Response Surface Methodology approach (RSM) was used to determine optimum conditions for the osmotic dehydration of carrot cubes in sugar beet molasses. Treatment times were set to 1, 3 and 5 h, at temperatures of 45, 55 and 65?C and molasses concentrations were 40, 60 and 80% (w/w). The used responses variables were: final dry matter content (DM), water loss (WL), solid gain (Sg), and water activity (aw). A Box and Behnken?s fractional factorial design (2 level-3 parameter) with 15 runs (1 block) was used for design of the experiment. DM, WL, Sg were significantly affected by all process variables (at 90-95% confidence level). The optimum conditions were determined by superimposing the contour plots, with the following response limiting values: DM 50-60%, WL 0.7- 0.8, Sg 0.08-0.09, and aw 0.84-0.86. The optimum conditions generated were: treatment time of 4h, temperature of 60?C, sugar concentration of 66% (w/w).

Effect of various design and operation parameters on performance of pilot-scale Sludge Drying Reed Beds

Thirteen pilot-scale Sludge Drying Reed Bed units have been constructed and operated under various design and operational characteristics. All the beds included a cobbles bottom layer, where perforated PVC aeration tubes were placed. One bed did not contain aeration tubes. Two gravel layers were placed above the cobbles layer. The setup included planted beds with common reeds and control units. Three sludge loading rates were examined: 30, 60 and 75 kg dm/m 2/yr. The dewatering efficiency of the planted units exceeded 95% volume reduction. The final dry matter content varied between 50 and 64%, depending on the applied SLR. Mineralization of the residual sludge also took place. VS content of the planted units decreased up to 20%, while nutrient concentration was also reduced. The presence of reeds, aeration tubes and a fine-grained material improved the system efficiency, while the material composition did not have any effect on efficiency. Moreover, the units were able to treat sludge with high concentration of Cr.

Numerical model of gravity drainage of compressible organic slurries

When belt filters or sludge beds are dimensioned, the chosen volumetric load and medium resistance must be considered carefully to ensure fast dewatering and high final dry matter content. This can be done if the settling rate, cake compressibility, and specific cake resistance are determined and the process modeled. We present a numerical model of the gravity drainage of biological sludge. As sludge forms highly compressible cakes, cake compressibility is included in the model. Model simulations indicate that cake compression greatly influences drainage; for example, drainage time decreases with squared volumetric load because specific cake resistance increases linearly with load. Drainage rate increases with medium resistance; however, at high medium resistance, cakes are more loosely packed so specific cake resistance is lower. Cakes form more rapidly and are more compressed if particles settle, so the average specific cake resistance increases and the drainage rate decreases at a high settling rate.

Gravity drainage of activated sludge: New experimental method and considerations of settling velocity, specific cake resistance and cake compressibility

A laboratory scale setup was used for characterization of gravitational drainage of waste activated sludge. The aim of the study was to assess how time of drainage and cake dry matter depended on volumetric load, SS content and sludge floc properties. It was demonstrated that activated sludge forms compressible cakes, even at the low pressures found in gravitational drainage. The values of specific cake resistance were two to three orders of magnitude lower than those obtained in pressure filtration. Despite the compressible nature of sludge, key macroscopic parameters such as time of drainage and cake solid content showed simple functional dependency of the volumetric load and SS of a given sludge. This suggests that the proposed method may be applied for design purposes without the use of extensive numerical modeling. The possibilities for application of this new technique are, among others, the estimation of sludge drainability prior to mechanical dewatering on a belt filter, or the application of surplus sludge on reed beds, as well as adjustments of sludge loading, concentration or sludge pre-treatment in order to optimize the drainage process.

Simultaneous saccharification and fermentation of acid-pretreated rapeseed meal for succinic acid production using Actinobacillus succinogenes

Rapeseed meal was evaluated for succinic acid production by simultaneous saccharification and fermentation using Actinobacillus succinogenes ATCC 55618. Diluted sulfuric acid pretreatment and subsequent hydrolysis with pectinase was used to release sugars from rapeseed meal. The effects of culture pH, pectinase loading and yeast extract concentration on succinic acid production were investigated. When simultaneous saccharification and fermentation of diluted acid pretreated rapeseed meal with a dry matter content of 12.5% (w/v) was performed at pH 6.4 and a pectinase loading of 2% (w/w, on dry matter) without supplementation of yeast extract, a succinic acid concentration of 15.5 g/L was obtained at a yield of 12.4 g/100 g dry matter. Fed-batch simultaneous saccharification and fermentation was carried out with supplementation of concentrated pretreated rapeseed meal and pectinase at 18 and 28 h to yield a final dry matter content of 20.5% and pectinase loading of 2%, with the succinic acid concentration enhanced to 23.4 g/L at a yield of 11.5 g/100 g dry matter and a productivity of 0.33 g/(L h). This study suggests that rapeseed meal may be an alternative substrate for the efficient production of succinic acid by A. succinogenes without requiring nitrogen source supplementation.

Gravitational drainage of compressible organic materials

AbstractA model was developed to simulate drainage of compressible particle suspensions, and study how cake compression and volumetric load influence the process. The input parameters were settling velocity, cake resistance and compressibility. These parameters were found using a new experimental method. Dextran‐MnO2 particle suspensions were drained as these resemble organic waste slurries with respect to settling and compressibility. It was demonstrated that cake compressibility must be taken into account to obtain adequate simulations. This implies that pressurized filtration resistances cannot be used for drainage simulations. In the filtration step, a distinct increase of dry matter from top to bottom of the cake was observed. During the subsequent consolidation, the cake compressed and a uniform dry matter profile was found. The final dry matter content of the cake increased with feed concentration and volumetric load. The drainage time increased proportionally with feed concentration and, more importantly, proportionally with squared volumetric load. © 2010 American Institute of Chemical Engineers AIChE J, 2010