Indikasi kerusakan dingin pada mentimun Jepang (Cucumis sativus L.) berdasarkan perubahan ion leakage dan pH

AbstractIn this study, the chilling induced in Japanese cucumber (Cucumis sativus L.) stored at chilled temperature and the changes in its quality during storage period were examined. Change in ion leakage and pH were used as indicator of chilling injury symptopms. The sample of cucumber were stored at 5ºC (chilling) and 25ºC (non chilling). Percentage of ion leakage for cucumber stored at 5ºC was higher than that at 25 ºC at storage time of 3, 6 and 9 days. The increase in the rate of ion leakage at 5ºC indicates the chilling induced of cell membrane. The increasing tendency of pH was observed for cucumber stored at 5ºC with the value at storage time of 9 days were higher than that at 25ºC. The increase in pH could be thought as the change in acid content which indicate the occurrence of chilling injury. Changes in ion leakage and pH indicate the change in membrane permeability which related to chilling injury. Keywords: chilling injury, ion leakage, pH, Japanese cucumber, low temperature storage Abstrak Tujuan dari penelitian ini adalah untuk menganalisis terjadinya gejala chilling injury pada mentimun Jepang (Cucumis sativus L.) yang disimpan pada suhu rendah. Perubahan ion leakage dan pH digunakan sebagai indikator terjadinya chilling injury. Sampel mentimun disimpan pada suhu 5ºC (suhu rendah) dan  and 25ºC (suhu ruang). Hasil pengamatan menunjukkan bahwa persentase dari ion leakage untuk mentimun yang disimpan pada suhu 5ºC lebih tinggi dibanding pada suhu 25 ºC pada periode penyimpanan 3, 6 dan 9 hari. Kenaikan laju ion leakage pada mentimun yang disimpan pada suhu 5ºC menunjukkan adanya pengaruh suhu rendah terhadap membran sel. Kecenderungan kenaikan pH terlihat pada mentimun yang disimpan pada suhu  5ºC dengan nilai lebih besar pada hari penyimpanan ke 9 dibandingkan dengan mentimun yang disimpan pada suhu 25ºC. Kenaikan pada pH menunjukkan terjadinya perubahan kandungan asam yang mengindikasikan terjadinya gejala chilling injury. Perubahan ion leakage dan pH menunjukkan terjadinya perubahan permeabilitas membran yang berkorelasi terhadap gejala chilling injury. Kata kunci: chilling injury, ion leakage, pH, mentimun Jepang, penyimpanan suhu rendahDiterima: 11 Oktober 2011; Disetujui: 20 Februari 2012

Separation Process of Nonpolar Gas Hydrate in Food Solution under High Pressure Apparatus

Separation process of nonpolar gas hydrate formation in liquid food was experimentally studied under high pressure container. Xenon (Xe) gas was selected as hydrate forming gas and coffee solution was used as a sample of liquid food. The high-pressure stainless steel container having the inner diameter of 60 mm and the volume of 700 mL with a U-shaped stirrer was designed to carry out this experiment. A temperature of 9.0 ∘ C and Xe partial pressure of 0.9 MPa were set as a given condition. The experiment was designed to examine the effect of steel screen size, formation rate, temperature condition, and amount of Xe gas dissolving in the solution on the separation process which was indicated by concentration efficiency. Screen size of 200 and 280 mesh resulted in higher concentration efficiency than that of 100 mesh. The higher stirring rate caused the higher formation rate of Xe hydrate and created the smaller Xe hydrate crystals. At the condition giving the same solubility in water, temperature of 14.8 ∘ C resulted in lower concentration efficiency than 9.0 ∘ C. The increase in the amount of Xe gas dissolving in coffee solution caused the concentration efficiency to decrease; however, the concentration ratio between the final and initial concentration of the solution increased

Transmission electron microscopic observations of nanobubbles and their capture of impurities in wastewater

Unique properties of micro- and nanobubbles (MNBs), such as a high adsorption of impurities on their surface, are difficult to verify because MNBs are too small to observe directly. We thus used a transmission electron microscope (TEM) with the freeze-fractured replica method to observe oxygen (O2) MNBs in solutions. MNBs in pure water and in 1% NaCl solutions were spherical or oval. Their size distribution estimated from TEM images close to that of the original solution is measured by light-scattered methods. When we applied this technique to the observation of O2 MNBs formed in the wastewater of a sewage plant, we found the characteristic features of spherical MNBs that adsorbed surrounding impurity particles on their surface

Effect of NaCl on the Lifetime of Micro- and Nanobubbles

Micro- and nanobubbles (MNBs) are potentially useful for industrial applications such as the purification of wastewater and the promotion of physiological activities of living organisms. To develop such applications, we should understand their properties and behavior, such as their lifetime and their number density in solution. In the present study, we observed oxygen MNBs distributed in an electrolyte (NaCl) solution using a transmission electron microscope to analyze samples made with the freeze-fracture replica method. We found that MNBs in a 100 mM NaCl solution remain for at least 1 week, but at higher concentrations decay more quickly. To better understand their lifetimes, we compared measurements of the solution's dissolved oxygen concentration and the -potential of the MNBs. Our detailed observations of transmission electron microscopy (TEM) images allows us to conclude that low concentrations of NaCl stabilize MNBs due to the ion shielding effect. However, higher concentrations accelerate their disappearance by reducing the repulsive force between MNBs

Separation Process of Nonpolar Gas Hydrate in Food Solution under High Pressure Apparatus

Separation process of nonpolar gas hydrate formation in liquid food was experimentally studied under high pressure container. Xenon (Xe) gas was selected as hydrate forming gas and coffee solution was used as a sample of liquid food. The high-pressure stainless steel container having the inner diameter of 60 mm and the volume of 700 mL with a U-shaped stirrer was designed to carry out this experiment. A temperature of 9.0°C and Xe partial pressure of 0.9 MPa were set as a given condition. The experiment was designed to examine the effect of steel screen size, formation rate, temperature condition, and amount of Xe gas dissolving in the solution on the separation process which was indicated by concentration efficiency. Screen size of 200 and 280 mesh resulted in higher concentration efficiency than that of 100 mesh. The higher stirring rate caused the higher formation rate of Xe hydrate and created the smaller Xe hydrate crystals. At the condition giving the same solubility in water, temperature of 14.8°C resulted in lower concentration efficiency than 9.0°C. The increase in the amount of Xe gas dissolving in coffee solution caused the concentration efficiency to decrease; however, the concentration ratio between the final and initial concentration of the solution increased

Storage in high-barrier pouches increases the sulforaphane concentration in broccoli florets

<div><p>Sulforaphane is a phytochemical that is usually found in cruciferous vegetables and is known to have a depressive effect on gastric cancer. Preliminary investigations showed that the sulforaphane concentration in broccoli (<i>Brassica oleracea</i> var. <i>italica</i>) florets increased under anoxia. Therefore, in the present study, we examined the effect of different atmospheric conditions on the sulforaphane concentration in broccoli and also tested whether there are concurrent effects on the concentration of ethanol, which is an unfavorable byproduct of fermentation. The sulforaphane concentration in broccoli florets was significantly elevated by 1.9- to 2.8-fold after 2 d of storage under hypoxia at ca. 0% O₂ and ca. 24% CO₂ at 20°C, whereas no such increase was observed following storage under normoxia at ca. 0% O₂ without CO₂ at 20°C. Furthermore, after 2 d, the sulforaphane concentration under hypoxia was 1.6- to 2.3-fold higher than that under normoxia. These results suggest that storage under hypoxia with high CO₂ levels can elevate the sulforaphane concentration in broccoli florets. However, the elevated sulforaphane concentration could not be maintained beyond 2 d. There was no significant difference in the concentration of ethanol between florets that were stored under hypoxia with/without CO₂ or normoxia at 2 d. However, the ethanol concentrations inside the pouches significantly increased between 2 d and 7 d. These findings indicate that the quality of broccoli florets can be improved through storage under hypoxia with high CO₂ levels at 20°C for 2 d.</p></div

Nanobubble Water’s Promotion Effect of Barley (Hordeum vulgare L.) Sprouts Supported by RNA-Seq Analysis

The physiological promotion effect of nanobubble (NB) water on living organisms is still a poorly understood phenomenon which was discovered 1 decade ago. Here, we analyzed the barley (Hordeum vulgare L.) embryo transcriptome following the exposure to NB water and low-concentration hydrogen peroxide (H₂O₂) using RNA-Seq. We found that 349 genes were differentially expressed after 24 h exposure to NB water and 97 genes were differentially expressed after exposure to H₂O₂ solution. Gene ontology enrichment and cluster analyses revealed that NB water induced expression of genes related to cell division and cell wall loosening. RNA-Seq, quantitative real-time polymerase chain reaction, and enzyme activity measurements all pointed to gene-encoding peroxidases as a major factor responsible for the effects of physiological enhancement due to NB water. The exogenous hydroxyl radical (•OH) produced by NB water significantly increased the expression of genes related to peroxidase and NADPH, thus leading to an increased endogenous superoxide anion (O₂^•–) inside the barley seed. Appropriately, low concentrations of exogenously added reactive oxygen species (ROS) and endogenous ROS played important roles in plant growth and development. When ROS levels were low, the endogenous ROS was eliminated by ascorbate peroxidase and other peroxidases instead of activating the catalase and superoxidase dismutase. This data set will serve as the foundation for a system biology approach to understand physiological promotion effects of NB water on living organisms

Identification of ROS Produced by Nanobubbles and Their Positive and Negative Effects on Vegetable Seed Germination

Exogenous reactive oxygen species (ROS) produced by nanobubble (NB) water offer a reasonable explanation for NBs’ physiological promotion and oxidation effects. To develop and exploit the NB technology, we have performed further research to identify the specific ROS produced by NBs. Using a fluorescent reagent APF, a Fenton reaction, a dismutation reaction of superoxide dismutase and DMSO, we distinguished four types of ROS (superoxide anion radical (O₂·^–), hydrogen peroxide (H₂O₂), hydroxyl radical (·OH), and singlet oxygen (¹O₂)). ·OH was confirmed to be the specific ROS produced by NB water. The role of ·OH produced by NB water in physiological processes depends on its concentration. The amount of exogenous ·OH has a positive correlation with the NB number density in the water. Here, spinach and carrot seed germination tests were repeatedly performed with three seed groups submerged in distilled water, high-number density NB water, and low-number density NB water under similar dissolved oxygen concentrations. The final germination rates of spinach seeds in distilled water, low-number density NB water, and high-number density NB water were 54%, 65%, and 69%, respectively. NBs can also promote sprout growth. The sprout lengths of spinach seeds dipped in NB water were longer than those in the distilled water. For carrot seeds, the amount of exogenous ·OH in high-number density NB water was beyond their toxic threshold, and negative effects were shown on hypocotyl elongation and chlorophyll formation. The presented results allow us to obtain a deeper understanding of the physiological promotion effects of NBs