• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.432-439
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• 2004

Increase in water vapor barrier properties of sodium alginate films was studied by preparing composite films with fatty acids, i.e., lauric, palmitic, stearic, and oleic acids, and by treatment with 3% $CaCl_{2}$ solution for 3 min. Film thickness, surface color, microstructure, tensile strength (TS), elongation at break (E), water vapor permeability (WVP), water solubility (WS), and sorption isotherm of films were investigated. Microstructure of films observed with SEM was changed by fatty acid and $CaCl_{2}$ treatments. TS decreased 25-70% depending on fatty acid used, and increased 1.5- to 2-fold by $CaCl_{2}$ treatment. E decreased by both fatty acid and $CaCl_{2}$ treatments. Except oleic acid, WVP decreased significantly (p<0.05) by forming composite films with fatty acids, particularly with stearic acid, WVP decreased more than two-fold. WS also decreased by fatty acid and $CaCl_{2}$ treatments. In stearic acid, WS decreased about 30-fold by combined treatment of fatty acid and $CaCl_{2}$. Sorption isotherm showed typical biphasic pattern with deliquescent point of 0.75. Results of isotherms and BET monolayer moisture content indicated hydrophilicity of film decreased by $CaCl_{2}$ treatment.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.217-221
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• 2003

Effect of direct addition of $CaCl_2$ into sodium alginate film-making solution and immersion of alginate films into $CaCl_2$ solutions on tensile strength (TS), percentage elongation at break (E), water vapor permeability (WVP), and water solubility (WS) of the films were investigated. TS of alginate films prepared by both methods increased. E of $CaCl_2-added$ films did not change significantly (P>0.05), whereas that of $CaCl_2-immersion$ films decreased significantly (p<0.05). WVP of films prepared by both methods decreased significantly, but the effect was more significant in the $CaCl_2-immersion$ films. Water resistance was not changed in the $CaCl_2-added$ films, whreras increased significantly in $CaCl_2-immersion$ films (p<0.05). Properties of alginate films depend on the concentration of $CaCl_2$ treatments in both methods, and they also depend on treatment time in the immersion method.

• Food Science and Preservation
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• v.14 no.5
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• pp.457-461
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• 2007

We investigated the effects of both $CaCl_2$ treatment and modified atmosphere packaging (MAP) (compared with non-packaging on 'Fuji' apples from the Young-Joo region of Korea. Apples were dined into 5% (w/v) $CaCl_2$ solution for 15 min and then packaged with or without LDPE film (thickness: 0.025 mm) before cold storage at $0^{\circ}C$. Weight loss of applies in film packaging was lower than that of non-packaging applies, and the apple firmness resulting from $CaCl_2$ treatment and MAP was better than that of apples receiving control treatment. Also, $CaCl_2$ treatment and MAP resulted in improvements in titratable acidity, soluble solid content (SSC), and decay rate compared to control treatments. However, no significant differences in vitamin C content were found amongst apples receiving various treatment. the results suggest that a combination of postharvest calcium dipping and plastic film packaging may effectively preserve 'Fuji' apples, and that the combined treatment are better than either individual treatment.

• The Journal of Natural Sciences
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• v.10 no.1
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• pp.57-61
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• 1998

Postharvest dipping of vacuum infiltration treatments of 'Chojuro' pear fruit in $CaCl_2$ resulted in increased calcium content, especially in fruit peel and outer flesh such as just below peel. As $CaCl_2$ concentrations increaced from 2% to 8% in dipping treatment, calcium content became higher. But vacuum infiltration under 200-600 mmHg did not affect and dipping and vaccum infiltration did not have any difference in fruit calcium content. Decreasing of fruit firmness determined at 4 weeks during storage was slower in fruits with $CaCl_2$ treatment than control.

• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.276-283
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• 2006

To evaluate the effectiveness of the foliar spray of calcium on "Baekdo" peach fruit, we carried out experiments in the orchards. The sprays were applied with $CaCl_2\;(Ca:\;400mg.kg^{-1})\;and\;CaCl_2$ with adjuvants (amino acid, $2g.kg^{-1}$; phytic acid, $2ml.kg^{-1}$ and wood vinegar, $2ml.kg^{-1}$) for four times from June 12 through July 4 at weekly intervals. The fruits and leaves were evaluated for Ca content, firmness and incidence of Brown rot caused by Monilinia fructicola at harvest To evaluate fruit quality included Ca content, firmness natural decay during the storage, the fruits were stored at room temperature for 14 days. The Ca content in leaf and fruit flesh at harvest was significantly increased (P=0.05) in $CaCl_2$ + amino acid treatment among $CaCl_2$ treatments. However, there was not significant Ca content in fruit peel. The firmness of flesh increased significantly (P=0.05) in $CaCl_2$ + amino acid treatment. The natural decay (Rhizopus stolonifers) during storage at the room temperature for 14 days, the fruit treated with $CaCl_2$ + wood vinegar exhibited lowest (P=0.05) incidence. Also, the firmness of the fruit during storage was firmer with treated $CaCl_2$ than untreated fruit. In the treatments of $CaCl_2$ + phytic acid and $CaCl_2$ + amino acid, it was possible to reduce incidence of Brown rot caused by M. fructicola most effectively in the field. In addition, inoculation with M. fructicola in fruits was also the most effective treatment for inhibiting disease development in vitro. These results suggested that the foliar spray of $CaCl_2$ with adjuvants increased the content of Ca and firmness of the fruits positively. It also inhibited the natural decay and the Brown rot effectively.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.12-16
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• 2001

This study was conducted to evaluate the effect of calcium chloride treatment (0.1%, 0.3%, and 0.5%) in red sweet pepper 'Ace' on the improvement of shelf-life and the physiological characteristics. $C_2H_4$ production and respiration rates of fruits treated with $CaCl_2$ before harvest decreased during storage of red sweet pepper at $7^{\circ}C$. Ca contents in the leaves and in the fruits showed also a greater increase in treatment of $CaCl_2$ than that in control. No difference was found in total sugar, whereas sucrose content was rapidly reduced after 20 days at $7^{\circ}C$. Ascorbic acid contents were increased by the $CaCl_2$ treatment. As Ca concentration is getting higher, the fruit decay rate was significantly reduced. From this result, we can positively conclude that foliar application with the concentration of 0.3% $CaCl_2$ and 0.5% $CaCl_2$ before harvest is effective in improving storage quality in red sweet pepper.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.152-156
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• 1998

This study was conducted to elucidate the changes of photosynthetic ability and cation content in barley cultivar seedlings cultured for 10 and 30 days with different NaCl concentrations containing 1/4 Hoagland solutions. At the highest NaCl concentration, the weight of dry matter and the shoot/root ratio (S/R ratio) were decreased. Thus, shoots were affected more than roots by NaCl treatment. The S/R ratio decreased more in 'Neulssalbori' than in 'Bunong' by the NaCl treatment. The. internal $Na^+$ concentration increased greatly with the highest NaCl concentration, but $K^+$ concentration in plants decreased with the highest NaCl treatment. The $Ca^{2+}$ concentration had a small change with NaCl concentrations. Thus $Na^+$/$K^+$and $Na^+$/$Ca^{2+}$ratios increased with the highest concentration. The chlorophyll content (%/dry weight) of seedlings decreased at higher NaCl levels except for Bunong in 30 day old seedlings. The photosynthetic ability decreased only for Neulssalbori in the 10 days NaCl treatment. The stomatal conductance, and transpiration had decreased in the 10 day old seedlings, but not with 30 day old seedlings.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.219-225
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• 2017

An aqueous chlorine dioxide ($ClO_2$) treatment combined with highly activated calcium oxide (CaO) and mild heat was tested for inactivating naturally existing bacteria and Escherichia coli O157:H7 inoculated on fresh-cut kale. Kale samples were treated with different concentrations of $ClO_2$ (10, 30, and 50 ppm), CaO (0.01%, 0.05%, 0.1%, and 0.2%), and mild heat ($25^{\circ}C$, $45^{\circ}C$, $55^{\circ}C$, and $65^{\circ}C$) as well with combinations of 30 or 50 ppm $ClO_2$ and 0.2% CaO at $55^{\circ}C$ for 3 min. An increasing concentration of $ClO_2$ and CaO significantly reduced the microbial population compared with the control. In addition, mild heating at $55^{\circ}C$ elicited greater microbial reduction than the other temperatures. A combined treatment of 50 ppm $ClO_2$ and 0.2% CaO at $55^{\circ}C$ reduced the population of naturally existing bacteria on kale by 3.10 log colony forming units (CFU)/g, and the counts of E. coli O157:H7 were below the detection limit (1 log CFU/g). In addition, no significant differences in the Hunter color values were evident in any treatment during storage. Therefore, a combined treatment of $ClO_2$ and active CaO at $55^{\circ}C$ can be an effective sanitizing method to improve the microbiological safety of fresh-cut kale without affecting its quality.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.69-74
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• 2004

'Mixing' and 'immersion' $CaCl_{2}$ treatment methods were tested for preparation of bio-degradable films using powders of sea mustard (Undaria pinnatifida) (leaf, stem, and sphorophyll), sweet tanlge (Laminaria japonica), and fusiforme (Hizikia fusiforme) by extracting alginate through acid-alkali extraction method. Except fusiforme powder, flexible, free-standing films were produced by both methods using all marine algae powders tested. Except water solubility (WS), surface color, tensile strength (TS), elongation at break (E), and water vapor permeability (WVP) did not show distinct difference between $CaCl_{2}$, treatment methods. Although TS, WVP, and WS of marine algae powder films were lower than those of alginate films, they indicate potential in application as a new source of bio-degradable packaging materials.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.1
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• pp.13-24
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• 2001

Objective: In muscle and neuronal cells, calcium channels have been classified by electrophysiological and pharmacological properties into (1) voltage-dependent $Ca^{2+}$-channel (1) P/Q-type $Ca^{2+}$-channel (2) N-type $Ca^{2+}$-channel (3) L-type $Ca^{2+}$-channel (4) T-type $Ca^{2+}$-channel (5) R-type $Ca^{2+}$-channel. The present study was done in order to investigate whether there is any difference in $Ca^{2+}$-channel distribution between activated and normally fertilized embryos. Methods: The immunocytochemical method was used to identify the existence of voltage-dependent $Ca^{2+}$-channels in parthenogenetically activated 2-cell embryos by ethanol and $SrCl_2$ treatment. These 2-cell embryos were obtained by exposure to 6% ethanol for 6 min and to 10 mM $SrCl_2$ for 2h. Results: P/Q-type $Ca^{2+}$-channels and L-type $Ca^{2+}$-channels have been identified. Whereas, three type of $Ca^{2+}$-channel P/Q-type, N-type, L-type have been identified in 2-cell embryos fertilized in vivo. Conclusion: Activation by ethanol was faster than those by $SrCl_2$. However, there was difference in DAB staining of the embryos between ethanol and $SrCl_2$ treatment (87.7% and 54.1 %). Intensity of staining was also different between ethanol- and $SrCl_2$-treated group. However, it has not been known why there was some difference in DAB staining and staining intensity in the present study.