Soluble Matter Content Research Articles

Development of cross‐linked polyvinyl alcohol/sodium caseinate/silver nanoparticle electrospun mats for antibacterial wound dressing

AbstractIn this study, nanofibers were produced by the electrospinning method by adding 1%, 3%, 5%, and 7% silver nanoparticles (Ag NPs) into the polyvinyl alcohol/sodium caseinate (60/40, w/w) mixture. Electrospun materials were cross‐linked by immersion in a glutaraldehyde bath. Thus, antibacterial wound dressings that could be used on exuding wounds were developed. According to the scanning electron microscopy images of nanofibers, the cross‐linking process by immersion method did not cause negative effects such as breakage or adhesion on the surface of fibers. The cross‐linking of nanofibers was demonstrated by the presence of acetal linkages by Fourier‐transform infrared spectroscopy analysis. The cross‐linking process significantly improved the thermal properties of the nanofibers. The lowest crystallinity calculated in the differential scanning calorimeter was observed in the 3% Ag NP‐added nanofiber with a value of 1.83%. It exhibited the lowest total soluble matter content with a value of 11.98% owing to its high cross‐linking density. In addition, the 3% Ag NP‐added nanofiber, which had the highest toughness and ductility, displayed the highest tensile stress with 3.5 MPa and the highest tensile strain with 7.53%. Moreover, it showed 78.11% cell viability on the L929 fibroblast cell line at the end of the 24th hour. It was indicated that although the electrospun mats maintained 100% antibacterial effectiveness, they could not be used as a wound dressing for 48 h. It was reported that only 3% Ag NP‐added nanofiber could be used as a 100% effective antibacterial wound dressing for both Escherichia coli and Staphylococcus aureus provided that it was renewed every 24 h. Consequently, it was notified that cross‐linking by the immersion method can be used in biomedical applications.Highlights The antibacterial effects of Ag NP‐doped PVA/NaCAS electrospun mats were significant. The cross‐linking process did not induce toxic effects some of the nanofibers. High cross‐linking density was observed in the nanofibers. The swelling property of nanofibers is a good feature required in an ideal wound dressing.

Exogenous 6-BA enhances salt tolerance of Limonium bicolor by increasing the number of salt glands.

Exogenous 6-BA can increase endogenous hormone content, improve photosynthesis, decrease Na+ by increasing leaf salt gland density and salt secretion ability, and reduce ROS content so that it can promote L. bicolor growth. 6-benzyl adenine (6-BA) is an artificial cytokinin and has been widely applied to improving plant adaptation to stress. However, it is rarely reported that 6-BA alleviates salt damage of halophytes. In this paper, we treated Limonium bicolor seedlings, a recretohalophyte with high medicinal and ornamental values, with 300mM NaCl and different concentrations of 6-BA (0.5, 1.0, and 1.5mg/L) and measured plant growth, physiological index, the density of salt gland, and the salt secretion ability of leaves. The results showed that exogenous applications 1.0mg/L 6-BA significantly improved plant growth and photosynthesis, increased cytokinin and auxins contents, K+ and organic soluble matter contents, the activities of SOD, CAT, APX, and POD, and decreased Na+, H2O2, and O2- contents compared to that treated with 300mM NaCl. Further research showed that exogenous 6-BA significantly increased the density of salt gland and the salt secretion ability of leaves by upregulating the expression of the salt gland developmental genes, therefore, can secrete more excess Na+, and thus reduces the Na+ concentration in leaves, which can alleviate Na+ damage to the species. In all, exogenous 1.0mg/L 6-BA can increase endogenous hormone, improve photosynthesis, decrease Na+ by increasing secretion ability, and reduce ROS content of L. bicolor so that it can improve the growth. These results above systematically prove the new role of 6-BA in salt tolerance of L. bicolor.

Characterizations of corn starch edible films reinforced with whey protein isolate fibrils

Starch-based films have been widely researched because of its degradability and low cost. The aim of this work was to evaluate the effect of the addition of protein fibrils, especially the content and the morphology of fibrils, on the properties of starch-based films. Corn starch/whey protein isolate fibrils (CS/WPIF) films were prepared using CS added with different WPIF contents (0.2%, 0.4% and 0.6%) at pH 2.0 or 7.0. The morphology of WPIF was adjusted via changing pH at 2.0 or 7.0, in which WPIF at pH 2.0 was longer than that at pH 7.0 as shown in transmission electron microscopy. The addition of WPIF at pH 2.0 or 7.0 increased the tensile strength, relative crystallinity, and storage modulus of CS films, and reduced the water content, total soluble matter content and water vapor permeability of the films. Compared with the short fibrils at pH 7.0, the long fibrils at pH 2.0 better improved the functional properties of CS films due to a strong network structure of long fibrils. CS/WPIF films with 0.4% WPIF exhibited the best properties, and WPIF at 0.6% reduced the film performance, which might be due to the aggregation of excessive WPIF. Also, CS/WPIF films showed superior antioxidant properties and inhibited the browning of fresh-cut apples during storage.

Evaluation of Uncertainty in Determination of Soluble Content of Plastic Body Modified Asphalt Waterproof Coil

Plastic body modified asphalt waterproof rolling material should be tested for soluble substance content in accordance with the provisions of 5.3 Material performance clause in GB 18243-2008 Plastic Body Modified Asphalt Waterproof Rolling Material, and the corresponding minimum soluble substance content requirements are given according to the type and thickness of the rolling material. Soluble substance content detection shall be conducted according to the method specified in GB/T 328.26-2007 Test Method for Building Waterproof Roll Part 26 Soluble Substance Content of Asphalt Waterproof Roll (impregnated Material Content). In this assessment, the soluble matter content of APP I PY M PE 3 10 products produced by an enterprise was determined according to the corresponding standards, and the measurement uncertainty of this test was assessed according to the test process and results. The results were calculated as follows: The relative standard uncertainty of soluble content of the plastic body modified asphalt waterproof coil is μ= 34.42g/m2, and the extended uncertainty is U=(2482 ± 69) g/m2. The data is taken as an integer according to the standard, so the extended part certainty is 69g/m2. It can be seen from the process of evaluating measurement uncertainty that its main source is the introduction of weighing mass before and after specimen individual differences.

Effect of heat and pulsed electric field treatment on the physicochemical and nutritional properties of carrots.

Carrots are widely used in home cooking and vegetable processing industries because of their high nutritional value. However, different processing methods may produce a negative impact on carrot texture and nutrition quality. Therefore, the development of better processing methods to preserve the texture and nutrition quality of carrots will be beneficial to the carrot industry. The effects of heat and pulsed electric field (PEF) treatments with different heat temperatures (T) and holding time (th ) on comprehensive changes in thermal efficiency profiles, and physicochemical (color, hardness, cell structural damage) and nutritional (releasable β-carotene contents) properties of carrots were studied. In addition, electrical conductivity (σ) and soluble matter contents (°Brix) were determined for the heat-treated extracts. The value of total color difference (∆E) and cell structural damage index (Z) of carrots, σ and °Brix of extracts all increased with increasing T and th under different heat experimental conditions, whereas the value of cutting force (F) presented an opposite tendency and content of releasable β-carotene decreased after th > 2min at T=100 °C. The results show that PEF heating is beneficial in preventing changes in physicochemical and nutritional properties of carrots compared to traditional heat treatment. PEF has potential as a heating technology in the food industry. © 2022 Society of Chemical Industry.

Physico-chemical characteristics of rice protein-based novel textured vegetable proteins as meat analogues produced by low-moisture extrusion cooking technology

Currently, active research is being focused on the development of future foods that can replace conventional meat. Meat analogues have been drawing considerable attention as possible alternatives to meat. In this study, the possibility of using rice protein isolate (RPI) to create meat analogues was investigated. Therefore, novel textured rice proteins (TRPs), which are meat analogues, were prepared from RPI and soy protein isolate (SPI) as primary raw materials by blending RPI and SPI at ratios approximately 25:75, 50:50, 75:25, and 100:0 (w/w). Meanwhile, corn starch and wheat gluten, minor ingredients, were added at 29% and 13% (w/w) of the total weight of the all ingredients, respectively, in all samples. Low-moisture extrusion cooking process using a twin-screw extruder was used for manufacturing TRPs. An analysis of physico-chemical characteristics showed that RPI replacement decreased specific mechanical energy, porosity, and water absorption capacity of the meat analogues. However, meat analogues made from combinations of RPI and SPI had better nutritional quality than commercial one, whose main ingredient is SPI without the addition of RPI and displayed desirable results pertaining to their soluble matter content during rehydration. Consequently, RPI exhibits potential to partially replace SPI in the manufacture of meat analogues.

Effects of ultrasound-assisted low-concentration chlorine washing on ready-to-eat winter jujube (Zizyphus jujuba Mill. cv. Dongzao): Cross-contamination prevention, decontamination efficacy, and fruit quality

Wash water is circulated for use in the minimal processing industry, and inefficient disinfection methods can lead to pathogen cross-contamination. Moreover, few disinfection strategies are available for ready-to-eat fruits that do not need to be cut. In this study, the use of chlorine and ultrasound, two low-cost disinfection methods, were evaluated to disinfect winter jujube, a delicious, nutritious, and widely sold fruit in China. Ultrasound treatment (28 kHz) alone could not decrease the cross-contamination incidence of Escherichia coli O157:H7, non-O157 E. coli, and Salmonella Typhimurium, and free chlorine treatment at 10 ppm decreased the incidence from 55.00% to 5.00% for E. coli O157:H7, 65.00% to 6.67% for non-157 E. coli, and 70.00% to 6.67% for S. Typhimurium. The cross-contamination incidence was completely reduced (pathogens were not detected in sample) when the treatments were combined. The counts of aerobic mesophiles, aerobic psychrophiles, molds, yeasts, and three pathogens in the group subjected to combination treatment (28 kHz ultrasound + 10 ppm free chlorine) were significantly lower than those in the control, chlorine-treated, and ultrasound-treated groups during storage (0–7 d at 4 °C). Analysis of weight loss, sensory quality (crispness, color, and flavor), instrument color (a*/b*), soluble matter contents (total soluble solids, reducing sugar, total soluble sugar, and titratable acid), and nutritional properties (ascorbic acid and polyphenolic contents) indicated that treatment with ultrasound, chlorine, and their combination did not lead to additional quality loss compared with properties of the control. Additionally, the activities of phenylalanine ammonia-lyase and polyphenol oxidase were not significantly increased in the treatment group, consistent with the quality analysis results. These findings provide insights into disinfection of uncut ready-to-eat fruits using a minimum dose of disinfectant for cross-contamination prevention under ultrasonication. The use of ultrasound alone to decontaminate fresh produce is accompanied by a high risk of pathogen contamination, and the use of sanitizers to decrease cross-contamination incidence is recommended.

Pilot-scale extraction of polyphenols from spent black tea by semi-continuous subcritical solvent extraction

Spent black tea (SBT) is a residue from tea beverage production and considered as a potential source of active polyphenols. This study aimed to develop a pilot-scale process on semi-continuous subcritical solvent extraction (SSE) of polyphenols from SBT by exploiting the lab-scale knowledge. Treatment of SBT with ethanol–water (50% w/w) as solvent at 125 °C and 0.3 MPa achieved a significantly higher yield of polyphenols (80.82 g gallic acid equivalents/kg black tea) with antioxidant activity (64.20 g gallic acid equivalents/kg black tea), compared to hot water extraction (HWE). SSE increased the soluble matter content in extracts than HWE. Based on the results of LC-MS, theaflavin-3,3′-digallate was the most abundant polyphenol from a total of 12 compounds to be extracted by SBT with 50% ethanol. The results suggested that SSE can be used as a scale-up extraction method to recover polyphenols from SBT.

Simplified methods of estimating fermentable sugar yield in sweet sorghum [Sorghum bicolor (L.) Moench] stems

Fermentable sugar is the most important component in sweet sorghum stem for its first-generation ethanol production. Estimation of fermentable sugar yield is required for sweet sorghum breeding, production, but related estimation methods available now are not so efficient. In order to establish a new method of estimating fermentable sugar yield, sweet sorghum stems were milled with a small three roll miller to recover carefully the juice and bagasse. The contents of sugars in the juice and water extraction of bagasse were analyzed with high performance liquid chromatography. Contents of soluble matter and sugars (glucose, fructose and sucrose) of the extracted juice and calculated juice of the bagasse (moisture content plus soluble matter content) were compared. The results showed that there is no significant difference in the total fermentable sugar content between squeezed juice and residue juice. So, the following four methods of analysis and estimation for sugars content of the whole stem was studied and compared: (1) analyzing juice only (but needs to determine moisture content of bagasse or stem, (2) analyzing bagasse only, (3) analyzing both juice and bagasse and (4) analyzing dried stems. The results showed that it is feasible to estimate sugars content of the whole stem by analyzing the juice or the bagasse only, and the most simplified method was that analyzing the juice and drying the bagasse. The following three formula was postulated that can be used in the estimation of sugars contents: (1) Ss=(J + B × Soj ×Wb / Wj)×Sj; (2) Ss=(1-B × Db×Ub)×Sb /(Wb + Sob); (3) Ss=J × Sj + B × Sb, where Ss is sugar content of stem (%), J is juice extraction (%), B is bagasse rate after one milling (%), Soj is content of soluble matter in extracted juice(%), Wb is water content of bagasse (%), Wj is water content of extracted juice (%); Sj is sugar content of juice(%); Db is content of dried matter in bagasse(%); Sb is sugar content of fresh bagasse; Sob is content of soluble matter in fresh bagasse. Fermentable sugar yield (FSY, MgHa−1) = Green stem yield (GSY, MgHa−1) ×Ss (%).

Comparative varieties characteristics of watermelon accessions of ukrainian and foreign breeding

Aim. Evaluation of the common watermelon gene pool in terms of yield, marketable fruit weight and dry soluble matter content and isolation of the most valuable accessions for use in breeding programs. Results and Discussion. The article presents the results of studies on the assessment of 153 samples of common watermelon of Ukrainian and foreign selection in terms of yield, weight of marketable fruit and the content of dry soluble substances. One accession with very high level of fruit yield (> 113% to the standard) was selected – accession Lad (62,3 t/ha) from Ukraine. With high level of yield (> 101% to the standard), samples from Russia were selected: Solntsedar (55,7t/ha), Podarok Solntsa (58t/ha) and Samurai (58,3t/ha). With yield closed to the standard (97,7%) there was a sample from Russia – Shapka Imperatora (53,5t/ha). The mass of marketable fruit, 5 samples were the best: Solntsedar (2,5 kg), Lad (2,6 kg), Yatum (2,86 kg), Samurai (3,04 kg), Podarok Solntsa (3,99 kg). According to the content of dry soluble matter, samples from Ukraine were selected as a source for breeding: Alyi solodkyi (14%) and accession from Czech Republic Sugar baby (15%). According to the complex of features (consistently high yield, high taste), the following samples are of practical value for breeding: Lad, Yatum, Alyi solodkyi (Ukraine); Solntsedar, Podarok Solntsa, Samurai (Russia), Sugar baby (Czech Republic). Conclusions. Based on the results of the study of 153 collection accessions of common watermelon during 2018–2020. Accessions were selected: 4 by yield (55,7-62,3t/ha), 5 by fruit weight (2,51-3,99 kg), 2 by content of dry soluble matter (14-15 mg%), 7 by complex of valuable features.

Enhancement of biogas production from agricultural wastes via pre-treatment with advanced oxidation processes

The effects of advanced oxidation processes (AOPs) including Fenton, ozone, and ozone combined with Fe(II) and H2O2 on disintegration/solubilization of three mixed agricultural solid wastes and subsequent anaerobic digestion were studied. Hydroxyl radicals (̇OH) generated from AOPs enhanced the oxidation of COD and solubilization of particulate COD (>0.45 µm). Upon treatment, substrates lost 15.2 to 29.5% of their solids, 33.6 to 37.5% of total chemical oxygen demand, 16.5 to 25% of total biopolymers (humic acids and protein). The soluble matter content increased by 3–6 folds facilitating metabolization rate of the treated substrate resulting in a 23–30% increase in the cumulative methane production and 11.2–25% increase in % digestion efficiency (%ηAD). Semi-batch tests revealed that mixing fresh and pre-treated substrate using a 50:50 ratio improved both the specific methane production (1.7 folds) and volatile sold reduction (79%) with a positive effect on sludge dewaterability.

Ultrasound assisted purification of polyphenols of apple skins by adsorption/desorption procedure

The ultrasound (US) assisted purification of polyphenols of apple skins by adsorption/desorption on the poly-aromatic Amberlite adsorbent XAD-16 was studied. The adsorption steps were done at different temperatures (T = 25–40 °C) with application of US at different intensities (P = 0–400 W). The desorption steps were tested in aqueous ethanol solution at different concentrations of ethanol (Cet = 0–96%). The isotherm of polyphenol adsorption was well described using the Freundlich model. The data on adsorption kinetics and static isotherm evidenced the presence of adsorption on heterogeneous surface with broad distribution of adsorption times that can depend on content of polyphenols in the solutions and applied power of sonication. The studies of desorption revealed the optimum desorption efficiency of polyphenols at 50% concentration of ethanol. The desorption ratio was positively affected by the sonication during the adsorption step. The highest adsorption/desorption efficiency (recovery) was observed for polyphenols as compared with proteins and soluble matter content and it reached of ≈30.6% (0 W) and 68.9% (50 W) in absence and presence of sonication, respectively. The effects of high US power on the damage of XAD-16 were discussed. The obtained data evidenced on good perspective of application of adsorption/desorption procedure assisted by sonication for purification of polyphenols from apple skin extracts.

Moisture Sensitivity, Optical, Mechanical and Structural Properties of Whey Protein-Based Edible Films Incorporated with Rapeseed Oil.

The objective of this work is to study the effect of the rapeseed oil content on the physical properties of whey protein emulsion films. For this purpose, whey protein films with the addition of 0, 1, 2 and 3% of rapeseed oil, and glycerol as a plasticizer were obtained by the casting method. Film-forming emulsions were evaluated and compared using light scattering granulometry. The Sauter mean diameters (d32) of lipid droplets in film-forming solutions showed an increasing trend when increasing the oil volume fractions. The inclusion of rapeseed oil enhanced the hydrophobic character of whey protein films, reducing moisture content and film solubility in water. All emulsified films showed high lightness (L*≈90). Parameter a* decreased and parameter b* and total colour difference (∆E) increased with the increase of the volume fractions of oil. These results were consistent with visual observations; control films were transparent and those containing oil opaque. Water vapour sorption experimental data at the full range of water activity values from 0.11 to 0.93 were well described with Peleg's equation (R2≥0.99). The tensile strength, Young's modulus and elongation at break increased with the increase of rapeseed oil volume fraction, which could be explained by interactions between lipids and the protein matrix. These results revealed that rapeseed oil has enormous potential to be incorporated into whey protein to make edible film or coating for some food products. The mechanical resistance decreased with the addition of the lipids, and the opacity and soluble matter content increased.

Short term preservation of hide using vacuum: influence on properties of hide and of processed leather.

The objective of this work was to investigate vacuum influence on hide preservation time and how it affects hide structure. It was established that vacuum prolongs the storage time without hide tissue putrefaction up to 21 days when the storage temperature is 4°C. The microorganisms act for all storage times, but the action is weak and has no observable influence on the quality of hide during the time period mentioned. The hide shrinkage temperature decrease is negligible, which shows that breaking of intermolecular bonds does not occur. Optical microscopy, infrared spectroscopy and differential scanning calorimetry also did not show any structural changes which can influence the quality of leather produced from such hide. The qualitative indexes of wet blue processed under laboratory conditions and of leather produced during industrial trials are presented. Indexes such as chromium compounds exhaustion, content of chromium in leather, content of soluble matter in dichloromethane, strength properties, and shrinkage temperature were determined. Properties of the leather produced from vacuumed hide under industrial conditions conformed to the requirements of shoe upper leather.

Impact of apple processing modes on extracted juice quality: Pressing assisted by pulsed electric fields

The purpose of this study was to compare the effects of pulsed electric field (PEF) on apple juice characteristics (turbidity, polyphenolic content and antioxidant capacities). The pressing was used as a standard method for juice extraction. Experiments were carried out at a constant pressure ( P = 3 bar) using a laboratory press cell. Two different methods for PEF application at 400 V/cm were investigated (PEF treatment of whole samples before cutting and PEF treatment of apple slices after cutting). PEF treatment resulted in increase of the juice yield from 44 g/100 g apple (untreated samples) to 58 g/100 g apple (treatment of whole apples) and 64 g/100 g apple (treatment of slices) after 30 min of pressing. The analysis of pH and conductivity showed no significant difference between untreated and PEF-treated samples. However, the total soluble matter content of juice increased after PEF treatment. The obtained turbidity and transmittance data evidence a noticeable improvement of juice clarity for PEF-treated samples. The PEF pre-treatment was accompanied by an increase of the content of polyphenols and intensification of the antioxidant capacities of juice. Most of these effects (juice clarity and content of antioxidants) were more pronounced for the whole treated apples as compared to untreated apples and PEF-treated apple slices. The evolution of apple browning before and after PEF treatment was more pronounced for whole samples. PEF treatment accelerates browning. The obtained data can contribute to the determination of an optimum time for PEF application. The results evidence that PEF-enhanced expression is promising for production of higher quality juices. PEF treatment of whole apples reduces the energy consumption and is advantageous for industrial applications as compared to the treatment of apple slices. PEF combined with pressing can become a good alternative to traditional process.

Formulation and stability of biodegradable films made from cod gelatin and sunflower oil blends

Sunflower oil was added to cod gelatin in proportions of 0%, 0.3%, 0.6%, and 1% to improve the hydrophobic properties of the resulting films and decrease water vapor permeability and the soluble matter content. Mechanical and optical properties were evaluated to determine the influence of the added oil and the stability of the films during storage for one month. Adding oil increased film thickness, whiteness, optical absorbance and decreased transparency; all these properties held stable over the storage period. Fourier transform infrared (FTIR) spectra revealed some lipid–protein interactions (hydrogen bonds, ester formation) and early oil oxidation. By the end of storage oxidation was well advanced and secondary oxidation products were present. Adding oil in any quantity decreased the puncture force but not the puncture deformation. Stability of these two mechanical properties decreased during storage in the films that contained ⩾0.6% added oil. Water vapor permeability did not decrease when oil was added and even increased with storage time, though adding oil yielded more insoluble films due to lipid–protein interactions.

A rapid method for the estimation of damaged starch in wheat flours

A new method was developed for determination of damaged starch in wheat flour. The method was based on the idea that the difference between the soluble matter contents of the extracts prepared from the same flour with and without alpha-amylase is mainly due to the action of alpha-amylase on damaged granules . The extraction stage of the method is similar to the AACC method (76-30A). However, after this stage a refractometer was used to measure Brix values of solutions instead of determination of reducing sugars. The sample size and incubation period of the AACC method were optimized for the proposed method using response surface methodology . The damaged starch levels of twenty-five commercial samples were determined by the proposed method as well as the two AACC Methods (No: 76-30A and 76-31). The results of the proposed method are compared with the results of the AACC Methods by using regression analysis. The correlation coefficients between the proposed method and both of the AACC Methods were 0.99. The average absolute differences between the proposed method and the AACC methods were 3.9 and 5.0%, respectively. The proposed method can be completed in 30 min with low number of experimental steps. The results showed that the starch damage values measured by the new method could be viewed with as much confidence as the traditional AACC Method 76-30A.

Relation between Infusing Condition of Green Tea and Soluble Component

The relation between infusing condition of Sencha (commongreentea) and soluble component in liquor was investigated as a basic research of green tea taste.Six grams of tea was infused with 180ml of water of 40, 60, 80 and 95°C for 2, 4, 6, 8 and 10 minutes, respectively. Content of solublematter, soluble nitrogen, caffeine, catechins, amino acids and reducing sugars in these infu-sions were analyzed and compared with each total content in original tea. The results were as follows.1. The most significant difference of infusing rate was observed between 60°and 80°C with all constituents.2. The infusing rate of catechins, especially epigallo catechin gallate were larger in high grade tea than in low one.3. Among the green tea constituents aminoacids were most easily extractable.4. Soluble nitrogen and tannin were generally more extractable in small size tea than in large size one, however, difference of infusing rate of tannin between both size tea became very small under high infusing temperature.5. The ratio of soluble nitrogen to tannin content was decreased as infusing temperature became higher.

Effects of soil moisture supplied at various growth stages on the growth and fruiting of young citrus trees

Experiments were carried out during three years period, from 1966 through 1968, to clarify the effects of soil moisture supplied at various growth stages on the growth, yield, and fruit qualities of young Satsuma orange trees.Six to eight years old trees (Oiwa No.5) grown on sandy loam in earthware pipes (60cm in diameter ×60cm in depth) were used as the materials.Water-regimes were designed as follows:Plot Periods of water regimessign May-June July-Aug. Sept.-Oct.A High Medium Medium(Low)B Low Medium Medium(High)C Medium(Low) High MediumD Medium(High) Low MediumE Medium Medium(Low) HighF Medium Medium(High) LowG Medium Medium MediumSoil moisture tension and moisture content on a percentage basis of water-holding capacity were pF=1 and 66% in wet-, pF=2 and 44% in medium-, pF=3 and 29% in dry-regime, respectively, on an average during the decade of 2 month. Sign in parenthesis indicates the water regime in 1968.Results obtained were summarized as follows:1. The growth of plants in new shoot, leaf number, trunk diameter and tree crown was good when supplied with wet- and medium-moisture in soil. The effect of drought period on the growth was decisive as the extreme during from July to August, followed by plot F regimed during from September to October in 1966. The number of flowers in the next spring was the largest in wetregimed during from July to August, and the next largest during from May to June, while the smallest in dry-regimes during the periods mentioned above, especially from July to August. There was a negative correlation between the number of shoot sprouting in the fall and the flower bearing in the next spring.2. Thickening growth of fruits was inhibited by the dry-regimes during each period, especially at the earlier stages of growth. Young fruits werealso dropped by this treatment. Yield and average weight of fruits was higher in wet- than in dryregimes. Color development in fruits was the best in dry-regime during the period from September to October, while the least in the other two dryregimes. Part of fruit rind was enlarged in dryregimes towards the later stages of growth. The content of soluble matter and citric acid in fruit juice was the highest in dry-regime during the period from September to October, while the lowest in wetregime during the same period. Fruit juice in the other two dry-regimes presented no good taste.3. The degree of water saturation deficit (W. S. D.) and diffusion pressure deficit (D. P. D.) in leaf was higher in dry- than in wet-regimes. There was a negative correlation between W. S. D. or D. P. D. and the rate of apparent photosynthesis and transpiration. Nitrogen content in leaf was higher in dry- than in wet-regimes, while phosphorus content in it was just the contrary.The pore space in dry-regimed soil was occupied by a higher proportion of soil air with less water. Soil pH was high in wet-regimes. Soluble salts and NO3-N concentrations in the soil solution were increased by lowering the soil moisture. In conclusion, the medium- and wet-regimes at various growth stages were highly desirable for the growth and yield of young citrus trees. Considering fruit qualities, the sequence of soil moisture supply seemed to be the best in wet- or medium- during the period from May to June, in medium- during from July to August, and in dry-regime during from September to October.

Studies on the pithiness of radish. IV.

Anatomical observation was made to elucidate the process of the occurrence of pithy tissue of the radish root.It is well known that the 2, 3, 5-triphenyl tetrazolium chloride (TTC) reaction, according to the difference in color intensity, reflects the physiological activity of fresh tissue in plants. In general, the tissue between the central part and the cambium ring in a cross section shows lower physiological activity than the others. Making this more in detail, the parenchyma which is apart from the conductive tissue is shown to become weak in the TTC reaction as the plant grows. Furthermore, if the esterified pectin is present in the cell wall of the parenchyma, a deep carmine color will appear by the hydroxamic acid reaction. Large parenchymatous cells which are far apart from the conductive tissue, however, show only a weak color reaction. On the other hand, staining with ruthenium red, though not specific for pectins, shows a reddish pink color in the presence of calcium pectate. Aged parenchymatous cells are stained with this dye. From these facts, it seems that the de-esterification and/or the splitting of pectin chain molecule is promoted and, consequently, the solubility of pectins in the middle lamella and the primary cell wall of parenchymatous cells changes as the radish root ripens. In this stage of root growth, it was found that the content of soluble matter in the tissues surrounding the vessels increased. These tissue are visible as transparent ones. These aged parenchymatous cells become large in size and thin in thickness of the cell wall, and are separated from the neighboring cells. According to the observations using the phase contrast microscope, the fusion of the cell plate melts away, but the union of the fibrillar bundle in the cell wall remains. As a result, the schizogenetic intercellular spaces are formed. In the observation, it was demonstrated that the occurrence of pithy tissue is accompanied with the dissolution of the middle lamella pectin and of the cementing material (probably protein) between the bundles of the fibrillar structure in the cell wall.Young cells surrounding the vessels and the sclerenchymatous cells developed from the meristem show a positive TTC reaction. It is also noted that the esterified pectin recognized in the middle lamella and in the primary cell wall shows deep carmine color by the hydroxamic reaction. Recently, WATANABE drew attention to the fact that some young parenchymatous cells and sclerenchymatous cells in fleshy roots possess an ability of cell division in the xylem parenchyma. It seems that these cells have an appropriate amount of desoxiribonucleic acid, kinins and auxins as the materials and/or the agent that induce cell division in the xylem parenchyma. The schizogenetic intercellular spaces do not appear in such young tissues. It may be concluded that from these observations that pithyness in the radish root is a phenomenon accompanied with the senescene of parenchymatous cells.