• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.727-731
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• 2009

Effects of various plasticizers (1.5%) such as glycerol, sorbitol, fructose, sucrose, and polypropylene glycol, and ferulic acid on the physical properties of Gelidium corneum (GC) film were examined. GC films containing plasticizer and ferulic acid were prepared by incorporating various amounts (10, 30, 50, 70, 100 mg/100 mL) of ferulic acid into the film. Water vapor permeability (WVP) of the GC film varied depending on the type of plasticizer, and among them the film containing sucrose had the lowest WVP. Tensile strength (TS) and % elongation (%E) of the film were in the range of $1.29{\sim}11.29$ MPa and $5.55{\sim}36.44$ %, respectively, and the WVP values were of $1.30{\sim}1.60\;ng\;m/m^{2}sPa$. In addition, the GC films were prepared using ferulic acid as a cross-linking agent. WVP of the film decreased with the addition of ferulic acid, and the film containing 30 mg ferulic acid had the lowest WVP value. TS value of the GC film containing 10 mg of ferulic acid was significantly higher than that of the control. However, further increase of ferulic acid concentration decreased the TS value. Therefore, 10 mg of ferulic acid was determined to be the optimal concentration for the film.

• Food Science of Animal Resources
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• v.29 no.3
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• pp.391-395
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• 2009

Gelidium corneum - gelatin (GCG) blend films containing fermented pollen extract (FPE) were prepared and used as a packaging material of pork loins. Water vapor permeability (WVP) of the film containing FPE was better than the control film, and the film's antimicrobial activity against Escherichia coli O157:H7 and Listeria monocytogenes increased with increasing FPE concentration. Addition of 0.15% FPE decreased the populations of Escherichia coli O157:H7 and Listeria monocytogenes by 2.98 and 3.68 Log CFU/g, respectively, compared to the control. Pork loin samples were inoculated with E. coli O157:H7 and L. monocytogenes and packed with the film. The samples packed with the GCG film containing 0.15% FPE had a decrease in the populations of E. coli O157:H7 and L. monocytogenes by 1.49 and 1.01 Log CFU/g after 4 d of storage, respectively, compared to the control. The results suggested that shelf life of the pork loins could be extended by packaging with the GCG film containing 0.15% FPE.

• Korean Journal of Food Science and Technology
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• v.53 no.5
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• pp.634-639
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• 2021

This study investigated the effects of cold plasma (CP) treatment on the properties of biopolymer films prepared with defatted mustard meal (DMM films). CP treatments using N₂, O₂, He, Ar, and dry air did not affect the tensile properties, water vapor permeability, color, and morphology of DMM films, whereas the treatments using He and Ar improved their printability. The tensile strength (TS) of O₂- or air-CP-treated DMM films and the elastic modulus (EM) of O₂-, He-, Ar-, or air-CP-treated films were lower than those of the untreated films. An increase in the power of Ar-CP treatment resulted in an increase in EM. The optimum treatment power and time for minimizing yellowness changes by Ar-CP treatment were 420 W and 40 min, respectively. The results demonstrated the potential application of CP treatment to improve the film properties of DMM films and possibly other agricultural by-product-based biopolymer films, making the films more applicable to food packaging.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.327-333
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• 2022

An orally disintegrating film (ODF) based on hyaluronic acid (HA) containing vitamin D was developed. The vitamin D content in the ODF was set based on the adequate intake (AI) of vitamin D from 0 to 10 AI (0, 1, 4, 7, and 10AI). The control (0AI) had the highest thickness and showed the longest disintegration time among the samples. The moisture content of the ODFs was significantly lower in those with vitamin D compared to the control. As the amount of vitamin D increased, the water vapor permeability (WVP) of the ODFs decreased, and the opacity significantly increased. The tensile strength was higher in the films containing vitamin D compared to the control films. However, the elongation at the break showed no significant difference among the films. The vitamin D content in the film was reduced by 25.7-44.2% during processing compared to the amount that was originally added. Based on the above results, a new and convenient vitamin D delivery system, an ODF, could be successfully produced.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.417-423
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• 2002

The edible films were prepared from the protein of alaska pollack, Theragra chalcogrmma. Effects of plasticizer, cross linker and laminated film on physical properties such as tensile strength (TS), elongation (E) and water vapor permeability (WVP) of films were investigated. In adding various kinds of plasticizers, TS of the films prepared with propylene glycol (PG) was the highest, and followed sorbitol, polyethylene glycol 200 (PEG 200) and glycerol. Elongation of the films prepared with glycerol was the highest, then sorbitol, PEG 200 and PG. WVP of films showed lower in order of PG, sorbitol, glycerol and PEG 200.75 decreased with the increment of plasticizer concentration, but elongation increased, The addition of both PG and PEG 200 effected weakly on elongation, so they were inadequate as plasticizer for the film. Mixtures of glycerol and sorbitol, which showed opposing both TS and elongation in the films, could control the physical properties of the films. With increasing relative humidity, TS decreased, while elongation and equilibrium moisture content increased. By adding the cross linkers such as ascorbic acid, citric acid and succinic acid, TS and m of films increased, while elongation decreased. Ascorbic acid, citric acid, succinic acid were most effective for TS at 0.2, 0.1 and $0.1\%, respectively. Laminated film with alaska pollack protein and corn zein improved TS above two times, reduced WVP about $20\~30\%$, as compared with the Elm from alaska pollack protein. Two films did not show the difference to oxygen permeability, but they showed about tenfold greater oxygen resistance than polyethylene film. Laminated film showed higher b and $\Delta$E value of color difference, lower a and L value than the film from alaska pollack protein.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.834-842
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• 2000

In order to investigate the characteristics of various sweet potato starches, gelatinization temperatures, solution viscosity of starch separated from two cultivars of the dry type sweet potatoes(Yulmi and Gunmi), one cultivar of moist type sweet potato(Jinmi), and one cultivar of purple colored variety(Jami) were compared, and properties of the edible films prepared with the starches were determined. Under a differential scanning colorimetry(DSC), initial temperatures for starch gelatinization of the dry type sweet potatoes (Yulmi and Gunmi) were higher than that of the moist type sweet potato (Jinmi), and that of Jami was close to those of the dry type ones. The sweet potato starch solutions tested by a cone and plate viscometer, showed peudoplastic characteristics. The moist type sweet potato was the most viscous followed by Jami, Yulmi, and Gunmi among the tested starch solutions. Total color difference of the edible films prepared with different cultivars of sweet potatoes showed appreciable differences between cultivars, caused by differences in Hunterb values. Water Vapor Permeability (WVP) of sweet potato starch films also showed significant differences between cultivars. Films prepared with the dry type sweet potato, Gunmi, showed the lowest WVP value of $0.83{\times}10^{-9}\;g\;{\cdot}\;m/m^{2}\;{\cdot}\;s\;{\cdot}\;Pa$, followed by Jami, Yulmi, and Jinmi. Water solubility of the films did not show any significant differences between cultivars. Tensile strength of the dry type sweet potato and Jami, which ranged 14.18-18.75 MPa, were higher than that of the moist type sweet potato, which was 4.66 MPa. Elongation values of the films, which were 5-6%, indicated that sweet potato starch films were not so elastic.

• Membrane Journal
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• v.21 no.2
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• pp.118-126
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• 2011

A method of light pre-irradiation, one of methods modifying hydrophobic surface to hydrophilic surface in a membrane, was proposed to overcome the drawback of previous methods such as blending, chemical treatment and post-irradiation, Process of membrane preparation in the study was comprised of 4 parts as follows: firstly process of precursor preparation to introduce hydrophilic nature under atmosphere and aqueous vapor by irradiating electron beam (EB), secondly process of dope solution preparation to cast on non-woven fabrics, thirdly process of casting to prepare membrane and finally process of coagulation in non-solvent to form porous structure. The merit of this method might show simple process as well as homogenous modification compared to previous methods. To carry it out, precursor was prepared by irradiating EB to powder PVDF at 75~125 K Gray dose. Precursor prepared was analyzed by FTIR, EDS and DSC to confirm the introduction of hydrophilic function and its mechanism. From their results, it was inferred I conformed that hydrophilic function was hydroxy1 and it was introduced by dehydrozenation. Hydrophilicity of membranes prepared was evaluated by contact angle (pristine PVDF : $62^{\circ}$, 125 K Gray-PVDF$13^{\circ}$). Porosity was evaluated by mercury intrusion method, simultaneously morpholoy and surface pore size were observed by SEM phothographs. The result showed the trend that more dose of EB led to smaller pore size and to lower porosity (pristine PVDF : 82%, 125 K Gray-PVDF : 63%). Trend of water permeability was similar to result above (pristine PVDF : 892 LMH, 125 K Gray-PVDF : 355 LMH).

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.5 no.1
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• pp.47-55
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• 1999

Applications of chitosan are related to molecular weight and degree of deacetylation(DOD) of chitosan completely. The molecular weight and DOD were greatly affected by the concentration of solution time and temperature. The degree of demineralization was not significantly different at $50^{\circ}C\;and\;70^{\circ}C$ after 30 minutes. Deproteinization decreased as process time increased. The nitrogen content was reached to 6.92% after 90 minute at $80^{\circ}C$, which is similar to theoretical nitrogen content of chitin. The DOD was 82.84% after 2 hours reaction and increased as the reaction time increased in the process. Viscosity and molecular weight are increased as recycling number of concentrated NaOH solution increased. Chemical, biological and physical properties of chitosan depend on the DOD and molecular size of the molecule. Tensile strength of the films from acetic acid solutions was between $28.9{\sim}33.6$ MPa and was generally higher than that of the films from lactic acid. Elongation of the films from lactic acid was between $97.0{\sim}109.7%$ and was generally higher than that of the films from the acetic acid. Water vapor permeability of the films prepared from lcetic acid solutions was between $1.9{\sim}2.3ng{\cdot}m/m^2{\cdot}s{\cdot}Pa$ and was generally higher than that of the films from the acetic acid.