Solids Content Research Articles

Physicochemical Alterations in Fruits Caused by Edible Coatings during Storage: A review

Fruits and vegetables are especially perishable due to their 80-90% water content by weight. Several strategies have been developed to retain and extend the freshness of packaged, transported and stored goods. Edible coatings are thin films applied to the exterior of fruits and vegetables to protect them from moisture, air and microbes. In the development of edible coatings, polysaccharides, proteins, lipids, composites and resins are among the most often employed materials. Packaging fresh fruits and vegetables is essential for preventing further contamination, damage and loss of moisture. The physicochemical effects of edible coatings on whole fruits include enhanced hardness, higher titratable acidity (TA) and better vitamin C, whereas the effects on fresh cuts include reduced water loss, increased soluble solid content (SSC) and preservation of product colour. The bulk of the effects might have been observed in both whole and freshly sliced fruits. This has aroused the interest of scholars, resulting in extensive research.

Preserving refrigeration and shelf life quality of hardy kiwifruit (Actinidia arguta) with alginate oligosaccharides preharvest application.

Alginate oligosaccharide (AOS) is a bioactive carbohydrate known for its preservation properties. However, the efficacy of preharvest AOS treatment in maintaining the postharvest quality of hardy kiwifruit (Actinidia arguta) has not been previously reported. This study explores the effects of preharvest AOS treatment (80mg L-1) on A. arguta fruit, assessing visual quality, physiological attributes, aroma, and antioxidant capacity during refrigeration and shelf life. Results showed that AOS treatment maintained higher lightness, chroma, firmness, and antioxidant levels (total phenolics, flavonoids, ascorbic acid, and glutathione), along with antioxidant enzyme activities (peroxidase, catalase, and ascorbate peroxidase). Specifically, AOS-treated fruit had 9% higher chroma and double the firmness after 60 days of refrigeration. AOS treatment reduced ripening and senescence, with 25% lower soluble solids content, 22% lower respiration rate, 30% lower ethylene production, and 35% lower malondialdehyde content. Electronic nose analysis indicated that AOS treatment suppressed changes in fruit aroma and off-odor development, maintaining significantly higher quality during the shelf life period. These findings demonstrate the effectiveness of AOS as a sustainable method to extend shelf life and preserve the quality of A. arguta fruit, enhancing its market value and consumer appeal. PRACTICAL APPLICATION: The research on using alginate oligosaccharides (AOS) for preharvest treatment of hardy kiwifruit (Actinidia arguta) has practical applications in the food industry. By extending the shelf life and preserving the quality of the fruit during storage, this method can help reduce postharvest losses and improve the market value and consumer appeal of A. arguta fruit. This sustainable preservation technique offers an eco-friendly alternative to traditional methods, enhancing the freshness and nutritional quality of the fruit available to consumers.

Scalable Extraction of Airway Mucins from Porcine Trachea.

Mucins are a major component of the innate defense system in the airways and their biological functions are important to consider in pulmonary disease research. However, the available mucus models for basic research relevant to the lung can be difficult to acquire in sufficient quantity to conduct such studies. Here, we present a new strategy to isolate airway mucins from pig trachea at the milligram to gram scale for use in pulmonary disease research. Using this protocol, we were able to isolate mucins with minimal DNA contamination consisting of ∼70% by weight protein. Compared to porcine gastric mucins extracted with the same procedure, the porcine tracheal extract possessed significantly greater O-linked glycoprotein (mucin) content. Particle tracking microrheology was used to evaluate the biophysical properties of porcine trachea mucins. We found porcine tracheal mucins formed a much tighter mesh network and possessed a significantly greater microviscosity compared to lab extracted porcine gastric mucins. In comparison to mucus harvested from human airway tissue cultures, we found porcine tracheal mucins also possessed a greater microviscosity suggesting these mucins can form into a gel-like material at physiological total solids concentrations. These studies establish an accessible means to isolate airway mucins from porcine trachea at large scale for use in pulmonary disease research.

CFD analysis of the erosion wear through 90° bend of different area ratio at high slurry concentration

Using the commercial computational fluid dynamics package ANSYS FLUENT, the behaviour of slurry erosion wear at 90° pipe bends was studied with varied area ratios (AR = 1–2). In this investigation, two influencing parameters have also been selected, such as slurry flow velocity (4−10 m/s) and the low to high slurry concentration of the fly ash (2.5%–40% by volume). To make a slurry, fly ash particles (150 µm) were mixed with water. Euler–Lagrange was used to forecast slurry erosion wear accurately. Simulations of the slurry flow within the bend pipeline were conducted with the help of a standard k-ɛ turbulence model and a two-way coupling approach. The findings of the simulation were validated against the existing research to ensure their accuracy. The study observed that the average erosion rate was directly proportional to the flow velocity and solid concentration of the slurry, while the average erosion rate was inversely proportional to the AR at all flow parameters. The findings indicate that the minimum and maximum erosion wear are found in AR = 2 and AR = 1, respectively. In the case of AR = 2, the average erosion rate is reduced by an average of 5.47 and 2.5 times at given flow parameters (slurry velocity and solid concentration) as compared to the AR = 1 and 1.5, respectively.

Potentially hazardous elements in atmospheric precipitation during the warm season (May–September) of 2019 in Moscow

Atmospheric precipitation acts as a significant pathway for pollutants from the atmosphere to the Earth’s surface, and analyzing urban precipitation data on intensity, fallout regime, transfer patterns, and solid particle content helps identify pollution sources. For the first time in the Moscow megacity, the levels of soluble forms of potentially hazardous elements (PHEs) in atmospheric precipitation were studied during the whole summer season of May–September 2019. The concentrations of Al, As, B, Ba, Be, Bi, Cd, Ce, Co, Cu, Fe, La, Li, Mn, Ni, P, Pb, Rb, Sb, Sn, Sr, and Zn were determined using inductively coupled plasma mass spectrometry and atomic emission spectroscopy methods. The research underscores the crucial role of atmospheric precipitation in washing PHEs out of the atmosphere. In May and September, concentrations of PHEs surpass the warm-season average. Notable contamination in May stems from elevated traffic during vacations, extensive burning of plant debris and wood, and pollen transport. Summer months are characterized by reduced forest and agricultural fires, traffic, and increased vegetation, leading to lower PHE concentrations, especially in July, with typical amount of precipitation contributing to pollutant dispersion. Elevated PHE levels in September are observed due to increased traffic load, biomass burning, and the expansion of unvegetated soil areas. Rainwater is enriched with Sb, Pb, Cd, Zn, Cu, B, Bi, P, and Sr, sourced from vehicle emissions, soil particles, industry, construction dust, biomass burning, and forest fires. Moderate enrichment with Ba, Mn, Ni, Co, and Sn also occurs episodically. Regression analysis highlights solid particles’ role as a major PHE source in rainwater, with the longer antecedent dry periods and the higher acidity level of rain intensifying the accumulation of PHEs. Long-range transport plays a lesser role, with Southern and Northern Europe, Western Siberia, and the central part of European Russia contributing meaningfully.

Typical Heterotrophic and Autotrophic Nitrogen Removal Process Coupled with Membrane Bioreactor: Comparison of Fouling Behavior and Characterization.

There is limited research on the relationship between membrane fouling and microbial metabolites in the nitrogen removal process coupled with membrane bioreactors (MBRs). In this study, we compared anoxic-oxic (AO) and partial nitritation-anammox (PNA), which were selected as representative heterotrophic and autotrophic biological nitrogen removal-coupled MBR processes for their fouling behavior. At the same nitrogen loading rate of 100 mg/L and mixed liquor suspended solids (MLSS) concentration of 4000 mg/L, PNA-MBR exhibited more severe membrane fouling compared to AO-MBR, as evidenced by monitoring changes in transmembrane pressure (TMP). In the autotrophic nitrogen removal process, without added organic carbon, the supernatant of PNA-MBR had higher concentrations of protein, polysaccharides, and low-molecular-weight humic substances, leading to a rapid flux decline. Extracellular polymeric substances (EPS) extracted from suspended sludge and cake sludge in PNA-MBR also contributed to more severe membrane fouling than in AO-MBR. The EPS subfractions of PNA-MBR exhibited looser secondary structures in protein and stronger surface hydrophobicity, particularly in the cake sludge, which contained higher contents of humic substances with lower molecular weights. The higher abundances of Candidatus Brocadia and Chloroflexi in PNA-MBR could lead to the production of more hydrophobic organics and humic substances. Hydrophobic metabolism products as well as anammox bacteria were deposited on the hydrophobic membrane surface and formed serious fouling. Therefore, hydrophilic membrane modification is more urgently needed to mitigate membrane fouling when running PNA-MBR than AO-MBR.

Application of a reaction-based water quality model to the total dissolved solids concentration of the Pasig River.

With the goal to support effective water resource management, water quality models have gained popularity as tools for evaluating the distributions of pollutants and sediments. This work focuses on the application of the numerical solution of an advection-dispersion-reaction (ADR) water quality model for rivers and streams to a major Philippine waterway, the Pasig River. The water quality constituent is described by a system of reaction and advection-dispersion-reaction equations. The model and method are based on a previously used strategy where Guass-Jordan decomposition is applied to the matrix system and the resulting conservative form of the model is solved numerically using the fully implicit scheme and finite element method. The methodology is demonstrated by a case study in Pasig River involving the concentrations of total dissolved solids (TDS) obtained from the Department of Environment and Natural Resources (DENR) through the Pasig River Unified Monitoring Stations (PRUMS) report. Sensitivity analysis and parameter estimation are also applied to the model to assess which parameters influence the model output the most.

Physiological responses of the Asian green mussel (<i>Perna viridis</i>) in highly turbid waters

In order to simulate conditions induced by climate change, the filtration rates and pseudofaeces production of Perna viridis from two distinct size categories were investigated at progressively increasing total suspended solid concentrations. Filtration rates of smaller mussels increased with increasing total suspended solid concentration. For larger mussels, filtration rates increased with increased concentration up to 800 mg L–1, after which filtration rate dropped sharply. Pseudofaeces production also increased with increasing total suspended solid concentration up to 600 mg L–1, beyond which no further significant increase was observed for large mussels, and there was a considerable decline for small mussels. The results show that the mussels of different sizes have different filtration rates with smaller mussels ranging from 0.11 to 2.62 mg min–1 and in larger mussels from 0.21 to 4.83 mg min–1. Pseudofaeces production ranged from 0.08 to 0.67 mg min–1 for small mussels and from 0.02 to 1.42 mg min–1 for larger mussels. These results may imply that smaller mussels are more vulnerable to siltation and high sediment load compared to larger individuals. In the natural environment, this situation can be caused by more frequent and severe typhoons resulting from climate change.

Nondestructively Determining Soluble Solids Content of Blueberries Using Reflection Hyperspectral Imaging Technique

Effectively detecting the quality of blueberries is crucial for ensuring that high-quality products are supplied to the fresh market. This study developed a nondestructive method for determining the soluble solids content (SSC) of blueberry fruit by using a near-infrared hyperspectral imaging technique. The reflection hyperspectral images in the 900–1700 nm waveband range were collected from 480 fresh blueberry samples. An image analysis pipeline was developed to extract the spectrums of blueberries from the hyperspectral images. A regression model for quantifying SSC values was successfully established based on the full range of wavebands, achieving the highest RP2 of 0.8655 and the lowest RMSEP value of 0.4431 °Brix. Furthermore, three variable selection methods, namely the Successive Projections Algorithm (SPA), interval PLS (iPLS), and Genetic Algorithm (GA), were utilized to identify the feature wavebands for modeling. The models calibrated from feature wavebands generated an RMSEP of 0.4643 °Brix, 0.4791 °Brix, and 0.4764 °Brix, as well as the RP2 of 0.8507, 0.8397, and 0.8420 for SPA, iPLS, and GA, respectively. Furthermore, a pseudo-color distribution diagram of the SSC values within blueberries was successfully generated based on established models. This study demonstrated a novel approach for blueberry quality detection and inspection by jointly using hyperspectral imaging and machine learning methodologies. It can serve as a valuable reference for the development of grading equipment systems and portable testing devices for fruit quality assurance.

Phytochemical Analysis and In Vitro Evaluation of Antidiabetic Potential of Banana Bract Lehya

Banana Bract Lehya, a traditional Ayurvedic formulation, has gained recognition for its potential therapeutic applications. This study aimed to prepare and evaluate the physicochemical properties and biological activities of Banana Bract Lehya. The lehya was prepared using banana bract powder (Musa paradisiaca), jaggery, tamarind, and a blend of spices including cumin, ajwain, ginger, fennel, and black pepper. Phytochemical screening revealed the presence of various bioactive compounds, with high concentrations of flavonoids and phenolic compounds, and moderate levels of tannins and terpenoids. Physicochemical analysis showed a pH of 6.20, loss on drying of 70%, total ash content of 3.2%, and total solid content of 96%. Organoleptic evaluation indicated a light brown and black color, pungent and spicy taste, and jelly-like texture. The total phenolic content was 78.5 ± 3.2 mg GAE/g, while the total flavonoid content was 42.3 ± 2.1 mg QE/g. Antioxidant activity, assessed by DPPH free radical scavenging assay, showed an IC50 value of 127.6 ± 5.4 μg/mL, compared to ascorbic acid's 23.8 ± 1.2 μg/mL. Glucose adsorption capacity increased with rising glucose concentration, suggesting potential anti-diabetic effects. The lehya exhibited concentration-dependent inhibition of α-amylase and α-glucosidase enzymes, with IC50 values of 156.3 ± 7.2 μg/mL and 143.7 ± 6.5 μg/mL, respectively, compared to acarbose's 83.2 ± 3.8 μg/mL and 95.6 ± 4.1 μg/mL. These findings provide valuable insights into the composition, physicochemical properties, and potential health benefits of Banana Bract Lehya.

Nitrogen, phosphorus, and carbon dynamics in biofloc system of Nile tilapia fed with high non-starch polysaccharides diet

While microbiota need to consume organic carbon to maintain water quality, commercial aquaculture feed produces a post-feeding waste with a carbon to nitrogen ratio that is too low to allow the bacteria to mineralize all the waste. The goal of this study was to investigate the effects of replacing starch-rich ingredients used in a Control-diet with non-starch polysaccharides (NSP) rich ingredients resulting in a High-NSP-diet on the water quality and nutrient budgets in biofloc tanks with Nile tilapia (Oreochromis niloticus). The main NSP-rich ingredients in the High-NSP-diet were palm kernel meal, rice bran and corn gluten feed. Both diets were isonitrogenous, but the High-NSP-diet contained 3 times more fiber than the Control-diet.After 8 weeks of cultivation, the individual fish growth and feed conversion ratio was similar between two dietary treatments, but due to a lower survival in tanks fed the High-NSP-diet the total biomass gain was slightly better in the Control-diet tanks. The contribution of biofloc to fish growth with the High-NSP-diet was 17 %, compared to 14 % when feeding the Control-diet. The water quality was similar between both dietary treatments, with less accumulation of nutrients in the water column in the High-NSP-diet tanks. This was shown by a 4 % lower retention efficiency of carbon (C), 12 % of nitrogen (N) and 7 % of phosphorus (P) in the water column in High-NSP-diet fed tanks than in the Control-diet tanks. The High-NSP-diet did not affect the C, N, and P concentration of the biofloc, with a relatively stable concentration of C and N among weeks and a steady increase in P concentration until week six (W6). The biofloc concentration increased until W6 and decreased in week eight.Correlation analysis revealed strong correlations between the concentrations of total suspended solids (TSS), total organic matter (TOM) and NO3, and between TSS and Chl-a. Subsequent regression analysis showed that the TSS concentration can be best predicted based on the TOM concentrations in tanks fed the Control-diet and based on the NO3 concentration in tanks fed the High-NSP-diet. This approach will help modellers or farmers to predict the amount of TSS based on a limited number of other water quality parameters. Economic analysis showed that in spite of a lower production at system level when feeding the High-NSP-diet, due to the lower cost of this diet, the effect on income is negligible, with a higher 0.03 USD profit per kg fish produced compared to the Control-diet.

Dynamic fluid flow model for phosphate slurry pipeline: OCP main pipeline as case study

The transportation of phosphate slurry through large-scale pipelines presents significant challenges due to the complex behavior of multiphase flows, particularly with varying solid content, density, and dynamic viscosity. Efficient and accurate prediction of flow behavior is critical for optimizing the operation of such pipelines. This work aims to develop a dynamic computational model to simulate phosphate slurry flow in pipelines. The case study focuses on the OCP Group’s main slurry pipeline, which links the mining sites at Khouribga to the industrial plants at Jorf Lasfar, Morocco. This pipeline system spans a total length of 187.124 km, consisting of 5237 pipes with an inner diameter ranging from 0.8546 m to 0.8578 m, and features several elevation changes along its ground level. Using a section-averaged, dynamic approach and the Finite Volume scheme, the model computes essential flow parameters, including density, dynamic viscosity, and pressure, for the incompressible and non-Newtonian slurry and process water flows. The model’s accuracy is validated against on-site measured data, showing an average deviation of ±0.32% for outlet density, and below 10% for pressure along the pipeline, underscoring the model’s reliability. Additionally, a sensitivity analysis was conducted to illustrate the impact of key parameters on the predicted head losses and pressures along the pipeline. This analysis shows that the slurry viscosity is the most critical parameter, significantly influencing these predictions. This model provides high accuracy and reasonable CPU time for real-time simulation and monitoring, while also offering significant potential for optimizing pipeline operations and ensuring the reliability of phosphate transport.

C/N ratio effect on oily wastewater treatment using column type SBR: machine learning prediction and metagenomics study

The sequencing batch reactor has emerged as a promising technology in treating wastewater; however, its application in the treatment of generated water still needs to be explored. This research gap led to the investigation of various carbon-to-nitrogen (C/N) ratios in a column-type sequencing batch reactor (cSBR). The resulting data and model demonstrated that augmenting the SND process with an external carbon source is effective until the C/N ratio reaches 15, ultimately eliminating nitrogen in the produced water. Conversely, a reduced C/N ratio can limit the ability of polyphosphate-accumulating organisms to incorporate carbon into polyphosphate synthesis, thereby decreasing phosphorus removal efficiency within the cSBR. When the C/N ratio ranged from 6 to 8, and the mixed liquor suspended solids concentration was high, the average phosphate removal was approximately 55%, compared to only around 25% when the C/N ratio was less than 6.

A vacuolar invertase gene SlVI modulates sugar metabolism and postharvest fruit quality and stress resistance in tomato

Abstract Sugars act as signaling molecules to modulate various growth processes and enhance plant tolerance to various abiotic and biotic stresses. Moreover, sugars contribute to the post-harvest flavor in fleshy fruit crops. To date, the regulation of sugar metabolism and its effect in plant growth, fruit ripening, postharvest quality and stress resistance remains not fully understood. In this study, we investigated the role of tomato gene encoding a vacuolar invertase, hydrolyzing sucrose to glucose and fructose. SlVI is specifically expressed during the tomato fruit ripening process. We found that overexpression of SlVI resulted in increased leaf size and early flowering, while knockout of SlVI led to increased fruit sucrose content, enhanced fruit firmness, and elevated resistance of postharvest fruit to Botrytis cinerea. Moreover, the content of naringenin and total soluble solids was significantly increased in SlVI knockout fruit at postharvest stage. Transcriptome analysis showed a negative feedback regulation triggered by sucrose accumulation in SlVI knockout fruit resulting in a downregulation of BAM3 and AMY2, which are critical for starch degradation. Moreover, genes associated with cell wall, cutin, wax, and flavonoid biosynthesis and pathogen resistance were upregulated in SlVI knockout fruit. Conversely, the expression levels of genes involved in cell wall degradation were decreased in knockout fruit. These results are consistent with the enhanced postharvest quality and resistance. Our findings not only provide new insights into the relationship between tomato fruit sucrose content and postharvest fruit quality, but also suggest new strategies to enhance fruit quality and extend postharvest shelf life.

Fast and simultaneous prediction of inner quality parameters on intact mangos by near infrared spectroscopy: Impact of spectra pre-processing on prediction accuracy

Near infrared spectroscopy or known as NIRS has been widely employed in many fields including agriculture, especially for sorting and grading of agricultural products. Spectra pre-processing is one of the main factors affecting model accuracy and prediction capabilities of NIRS. The objective of the present study was to study the impact of different spectra corrections namely mean centering (MC), mean normalization (MN), de-trending (DT), multiplicative scatter correction (MSC), standard normal variate (SNV) and orthogonal signal correction (OSC), to the prediction accuracy of quality parameters: titratable acidity (TA) and soluble solids content (SSC) in intact mango. A total of 91 mango samples (cv. Kent) were used as dataset for calibration and external prediction which was separated by means of systematic sampling based on a property (SSBP) approach. Diffuse reflectance spectra (log1/R) were acquired and recorded in wavelength range of 1000 – 2500 nm by Antaris Fourier transform NIR instrument. Judging from calibration and prediction performance, MSC found to be the best spectra pre-processing method prior to prediction model development with R2 prediction are 0.72 for TA and 0.76 for SSC. Although MSC increase the prediction performances based on R2, RMSE, RPD and RER metrics compared to the baseline, the achieved RPD, 1.9 for TA and 1.8 for SSC of this findings are still poor and need improvements to achieve even higher levels of accuracy and reliability necessitates for real-time applications.

Sensory approach to added sugar reduction in strawberry juices using fuyu persimmon

The aim of this study was to produce strawberry juice with reduced added sugar content, use the alternative natural sweetness of persimmon, and evaluate its physicochemical and sensory characteristics. Five different strawberry juice formulations were prepared with a 25% reduction in the added sucrose content with 0, 12.5, 25, 37.5, and 50% added persimmon pulp. Color, soluble solids, pH, and titratable acidity were evaluated, and CATA and acceptance sensory tests were performed with 100 consumers. In general, adding persimmon pulp to strawberry juice significantly affects both its physicochemical and sensory properties. From a physicochemical point of view, as the persimmon content increased, the strawberry juice tended to turn from red to orange, and there was an increase in soluble solids content and pH, as well as a decrease in acidity. From a sensory point of view, changes in sensory profile and product acceptability were also observed. However, persimmon showed potential as a natural sweetener in strawberry juice to reduce added sugar. Formulations with lower levels of persimmon pulp (12.5 and 25%) showed promise as these formulations maintained the valued sensory characteristics of strawberry juice and used the natural sweetness of persimmon to reduce added sugars, making them healthier beverage alternatives.

Determination of the Effects of Aminoethoxyvinilglycine (AVG) and Gibberellic Acid (GA3) Applications on Pre-Harvest Fruit Drop Amount and Fruit Quality in Hakko Pear Cultivar

This study was conducted to determine the effects of pre-harvest Aminoethoxyvinylgylcine (AVG) and Gibberellic acid (GA3) applications on the pre-harvest fruit drop amount and fruit quality in the 'Hakko' pear (Pyrus pyrifolia) cultivar grafted on BA29 rootstock in a private orchard in the Bala district of Ankara in 2021-2022. It was conducted in an orchard belonging to a producer. 50-100-150 mg/l AVG and 25-50-75 mg/l GA3 were applied 4 weeks before the estimated harvest date. Fruits are harvested at full maturity date; Pomological properties such as cumulative drop percentage, yield, fruit weight, fruit width and length, fruit stem width and length, fruit flesh firmness, fruit color, and chemical properties such as soluble solids content (SSC), pH and titratable acidity (TA) were evaluated. It was observed that all doses of AVG and GA3 during the harvest period reduced the cumulative casting rate compared to the control application (6.78%). In general, the yield per tree was found to be high in GA3 applications. In both AVG and GA3 applications, its effects on fruit weight, fruit width and length, fruit flesh firmness, SSC and pH were found to be statistically significant. It was observed that in both AVG and GA3 applications, the amount of fruit drop pre-harvest decreased and fruit quality characteristics were better than the control.

Investigation on the influence of particle size and porosity on solid phase fluidization and heat transfer in carbon fibre porous media

AbstractIn this paper, the 3D pore structure was reconstructed and solid phase fluidization in porous media was investigated. Based on the two fluid model, a computational fluid dynamics (CFD) model of gas–solid fluidization was established and the influence of particle size and porosity were investigated. When porosity was constant, during the fluidization process, the particle velocity and solid concentration standard deviation gradually decreased, and the bed height increased. At the same time, the smaller the particle size was, the smaller the solid concentration standard deviation was, the faster the bed height increased, and the more the particle temperature decreased. Based on the fixed value of particle size, when studying the effect of porosity on fluidization, it was found that with the enhancement of solid‐phase fluidization, particle velocity, solid concentration standard deviation, and particle temperature decreased, and bed height increased. Moreover, when porosity was large, particle velocity decreased rapidly, and solid concentration standard deviation reached a smaller minimum value, which took a longer time. Within the same time, the particle temperature also decreased less.

Effect of Nutrient Solution pH on the Growth and Quality of Lactuca sativa Grown in a Static Hydroponic System

Lettuce is an easy-to-grow and nutrient-rich leafy vegetable. It grows well using a static hydroponic system, which saves space and is easy to maintain. However, understanding pH’s impact on lettuce growth in static hydroponic systems is limited. Hence, this study was conducted to determine the effect of pH nutrient solution on the growth performance and eating quality of lettuce grown in a static hydroponic system. Lettuce was grown in pH 5.2, 6.2, and 7.2 nutrient solutions. Its growth performance was collected weekly, including plant height, root length, number of leaves, leaf area, leaf chlorophyll content, total dry weight, and total moisture content. The harvested lettuce was analyzed for firmness, soluble solids concentration, titratable acidity, pH, and ascorbic acid content by the fourth week after transplanting. The plant height, root length, number of leaves, leaf area, and total dry weight of lettuce were affected by the interaction between nutrient solution pH and weeks after transplanting. By the third week after transplanting, lettuce grown in pH 6.2 was 11.12 and 18.67% taller than those grown in pH 7.2 and 5.2 nutrient solutions, respectively. By the fourth week after transplanting, the firmness of lettuce grown in pH 6.2 was significantly higher than those grown in pH 5.2 and 7.2 nutrient solutions by 2.34 and 7.32%, respectively. It is concluded that lettuce should be grown in a pH 6.2 nutrient solution when using a static hydroponic system.

Exploring vacuum foam drying as an alternative to freeze-drying and spray drying for a human lipase

This article compares and explores vacuum foam-drying as an alternative drying technology to freeze-drying and spray drying for a recombinant human lipase as the model protein. Materials characteristics such as structure, surface composition and the solid-state properties of the dry materials were compared and investigated. Moreover, the technical functionality in terms of reconstitution characteristics and the lipase stability were also investigated. The stability of the lipase was evaluated through activity measurements. Sucrose and dextran D40 (40 kDa) were used as matrix former and the surfactant α-dodecyl maltoside was used as surface active additive. The study demonstrated that the drying technique greatly influenced the material structure and composition which in turn affected the reconstitution characteristics. The lipase was overrepresented at the material surface in declining order spray-dried > vacuum foam-dried > freeze-dried. The lipase activity was retained up to 10 % lipase content in solids, but at 20 % lipase a loss of activity was observed for all drying techniques. Phase separation in the solid material may be an explanation. Vacuum foam-drying shows promise as an alternative drying technique for the lipase, and potentially other proteins.