• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1184-1190
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• 1997

Corn zein coated carrageenan films were manufactured by immersing preformed ${\kappa}-carrageenan$ films into solution of different concentrations of corn zein (CZ) solids (10, 20, and 30% in 95% ethyl alcohol) with polyethylene glycol (20% w/w of CZ), glycerol (24% w/w of CZ). For all types of films, water vapor permeability (WVP), water solubility (WS), swelling ratio (SR), tensile strength (TS), percent elongation at break (E), heat sealing strength (HS), and Hunter color values (L, a, and b) were determined. WVP of corn zein coated ${\kappa}-carrageenan$ films decreased significantly (p<0.05) as the concentration of com zein increase. Coating with corn zein also decreased film WS and SR linearly with the concentration of corn zein. TS of corn zein coated carrageenan films decreased linearly with corn zein concentration. All the com rein coated carrageenan films showed heat sealing properties even though their sealing strength was less than half of corn zein film. Obviously corn zein coating affected color of ${\kappa}-carrageenan$ films, which was mainly caused by increase in yellowness (Hunter b-value).

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.520-523
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• 2007

Edible films of gelatin and com zein were prepared by incorporating nisin to the film-forming solutions. Com zein film with nisin of 12,000 IU/ml had an increase of 11.6 MPa in tensile strength compared with the control, whereas gelatin film had a slight increase with the increase of nisin concentration added. Water vapor permeability for both com zein and gelatin films decreased with the increase of nisin concentration, thus providing a better barrier against water. Antimicrobial activity against Listeria monocytogenes increased with the increase of nisin concentration, resulting in 1.4 log cycle reduction for com zein film and 0.6 log cycle reduction for gelatin film at 12,000 IU/ml. These results suggest that incorporation of nisin into com zein and gelatin films improve the physical properties of the films as well as antimicrobial activity against pathogenic bacteria during storage, resulting in extension of the shelf life of food products by providing with antimicrobial edible packaging films.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.68-72
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• 2005

Moisture sorption characteristics of edible composite films were determined and compared against moisture barrier properties. Edible composite films were Z1 (zein film with polyethylene glycol(PEG) and glycerol), Z2 (zein film with oleic acid), ZA1 (zein-coated high amylose corn starch film with PEG and glycerol), and ZA2 (zein-coated high amylose corn starch film with oleic acid). Z2 film showed the lowest equilibrium moisture content (EMC), monolayer value ($W_m$), water vapor permeability (WVP), and water solubility (WS). Surface structure of Z2 was relatively denser and finer than that of other edible films. GAB $W_m$ and C values decreased, while K values increased with increasing temperature. Correlation coefficients of WS:EMC and WVP:EMC at Aw 0.75 were higher than those of WS: $W_m$ and WVP: $W_m$, respectively. EMC values at Aw 0.75 appeared useful for evaluating or predicting moisture barrier properties of edible films.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.142-146
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• 2005

Soy protein isolate (SPI) film was laminated with corn zein or wheat gluten to improve functional properties. Both SPI/corn zein-laminated film (Film B) and SPI/wheat gluten-laminated film (Film C) showed increased tensile strength by 150%, compared to control (Film A). Film C showed significant 253% increase in percentage elongation. Water vapor permeability (WVP) of Films B and C decreased slightly compared to Film A. Solubility values of Films B and C were lower than that of Film A. Hunter color values of Films A and C were not significantly different, while Film B showed yellowness due to presence of corn zein. These results suggest SPI/wheat gluten-laminated film is suitable as packaging material.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.5
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• pp.413-423
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• 1990

Corn proteins have been known as nutritionally poor, being deficient in the essential amino acids. lysine and tryptophan. Improving the quality of protein in the corn grain would be a great benefit to the farmer. This study was conducted to evaluate the variation of the protein content and the protein constitution of the maize germplasms in the Crop Experiment Station in 1989. The average protein content of 101 germplasms was 11.5% with range from 8.0% to 17.3%. Elite hybrid field corns and table corns possessed 9.1-13.9% protein for the dried whole kernel. Major amino acids were glutamic acid and leucine. Lysine and methionine were limited. Varietal differences were observed in the amino acid composition. Qpm, a modified opaque-2 mutant had 1.4-1.7 times higher lysine content than Suwon 19, a dent corn and Suwon SS-21, a sweet corn. Suwon SS-21 had high threonine content. Maize seed protein gave three fractions. an alchol-soluble fraction (zein), an alkali-soluble fraction (glutelin), and a salt-soluble fraction (globulin) by the Osborne method. The zein fraction accounted respectively for 50.7% and 41.7% of the total protein is Suwon 19 and Suwon SS-21. The nonzein fractions increased in percentage of total protein in Qpm kernels. The amino acid composition of zein fraction from three types maize endoperms of dent, sweet and opaque-2 was essentially identical. Zein contained the high contents of glutamic acid and leucine but low content of lysine. The glutelin fractions of three types maize endosperms were mainly similar in overall amino acid composition. The lysine content of glutelin was higher than that of zein. The amino acid composition of globulin fraction was some different from those of zein and glutelin In Qpm it had higher levels of histidine and lysine than both of zein and glutelin. The increased lysine content in Qpm was resulted from changing the proportions of proteins which contained different levels of lysine.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.1 s.113
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• pp.45-53
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• 2006

This study was carried out to produce high functional and biodegradable coating agents for pulp mold by evaluating various kinds of biodegradable polymers. Five kinds of biodegradable polymers were used. In addition, the mixture of the carboxymethylated starch and biodegradable polymers(${\kappa}$-carrageenan, chitosan) were used for mixed coating agents. Physical properties of coated paperboards were evaluated. Conclusions obtained were as follows. 4% ${\kappa}$-carrageenan and 5% chitosan showed higher water and oil resistance. 10% sodium alginate, 4% corn zein and 15% polycaprolactone showed high water resistance while no improvement was found on oil resistance. The optimum mixture ratios for the mixed coating agents were 90:10(carboxymethylated starch : ${\kappa}$-carrageenan) and 50:50(carboxymethylated starch : chitosan). Since these mixed coating agents have excellent biodegradability with higher water and oil resistance, these can be used for the environmental-friendly coating agents.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1381-1387
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• 1998

Laminated films were prepared by casting corn-zein and fatty acid mixed solutions onto ${\kappa}-carrageenan$ films, and the effect of various fatty acids with different concentrations on the film properties such as water vapor permeabilities (WVP), tensile strength (TS) and elongation was investigated. WVP of the film decreased as concentration of fatty acids increased, and the lowest WVP value $(0.497\;ng\;m/m^2\;s\;Pa)$ was achieved with laminated films containing 30% lauric acid/corn-zein. The TS of laminated edible film seemed to decrease as the concentration of fatty acids increased, and TS of the laminated film was the highest (36.21 MPa) when the film contained 10% oleic acid. Weight loss of the minced mackerels packaged with corn-zein/carrageenan film which did not contain fatty acid was 11.7%, but weight losses of the samples packaged with oleic acid and lauric acid were 6.97% and 0.81%, respectively, after 30 days storage at $-20^{\circ}C$. The laminated films had an effect on preventing oxidation of the minced mackerels during storage because of high oxygen barrier property of the film. All of the minced mackerels packaged with the laminated films greatly reduced the peroxide value (POV) compared with unpackaged minced mackerels during storage. Also, thiobarbituric acid (TBA) values of the minced mackerels packaged with the laminated films were lower than that of unpackaged minced mackerels during storage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.358-362
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• 2004

In order to develop molecular markers related to stay green phenotype, AFLP analysis was conducted using near-isogenic lines for either stay green or non stay green trait. Both lines have characteristics of multi-ear and tillers (MET). Two out of 64 primer combinations of selective amplification identified three reproducible polymorphic fragments in MET corn with stay green. Both of E+AGC/M+CAC and E+AAG/M+CAA primer combinations produced two and one specific polymorphic fragments linked to stay green trait, respectively. For the conversion of AFLPs to sequence tag sites (STSs), primers were designed form both end sequences of each two polymorphic fragments. One fragment, which was amplified with E+AAG/M+CAA primer combinations, possessed 298 bp long and showed a $91\%$ homology with maize retrotransposon Cinful-l. One out of two polymorphic fragments produced with E+AGC/M+CAC primer combination had 236 bp long and matched a $96\%$ homology with an intron region of 22kDa alpha zein gene cluster in Zea mays. One out of two PCR fragments amplified with MET2 primer set in the stay green MET was not produced in the non-stay green MET. The developed AFLP and STS marker could be used as an efficient tool for selection of the stay green trait in the MET inbred.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2000.04a
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• pp.12-13
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• 2000

최근 플라스틱제 식품 포장재에 대한 환경학적 문제가 제기됨으로 인하여 다양한 곡류 단백질의 필름 형성능력에 많은 관심이 모아지고 있다. 단백질 필름으로서 soy protein, wheat gluten, rice bran, corn zein, glatin 및 colloagen 등의 소재들이 많은 관심을 모으고 있으며, 비교적 필름 형성력이 뛰어나고, 저렴한 가격으로 구입할 수 있는 대두 단백질에 커다란 관심이 모아지고 있는 실정이다. 이들 물질로부터 제조된 가식성 필름 및 코팅제들은 식품의 보존기간을 연장시킬 뿐만 아니라 수분 및 용질의 이동을 방지하여 식품의 품질을 개선시킬 수 있다. 또한 이들 필름 및 코팅제들은 산소 및 이산화탄소의 이동, 이로 인한 지방 산화 그리고 휘발성 향기성분들의 감소 등을 조절할 수 있다. 대두 단백질 필름의 사과 코팅제로서의 이용은 개별적 포장이 용이하지 않는 제품들의 코팅제로서 활용하여 대두 단백질 필름 및 코팅제의 잠재적 시장성을 확인하는 하나의 응용분야이다. 본 실험의 목적은 대두 단백질 코팅제를 후지와 golden delicious 사과에 코팅하여 상온 (22$^{\circ}C$)과 냉장온도(2-4$^{\circ}C$)에서 60일동안 보관하여 색도, 경도 및 산도 변화 등을 측정하여 저장 중 사과의 품질에 미치는 영향을 조사하였다. 대두 단백질 코팅제는 대두 단백 용액들 (5g, 8g, 10g/100mL water)에 glycerin (50% w/w의 단백질)을 가소재로 첨가한 후 알칼리 용액으로 pH 9.0에 맞추었다. 그런후 85$^{\circ}C$에서 30분간 가열하여 코팅제를 준비하였다. 후지 사과(붉은색)와 golden delicious 사과 (초록색)를 dipping 방법으로 코팅하여 60일도안 실온과 냉장온도에 저자하여 보존기간의 연장을 확인하였다. 사과품질의 결정인자는 Hunter L, a, b 색도값과 사과의 조직의 강도 (외부 및 내부) 그리고 산도 등을 측정하였다. 코팅된 후지 및 golden delicious 사과의 표피 및 내부 경도는 control과 비교하여 높은 경도를 유지하였다. 또한 냉장온도에서 30일 동안 보관하였을 때, control 사과와 거의 비슷한 경도를 유지하였다. 식품의 색도를 소비자의 기호를 결정하는 중요한 인자이다. 대두 단백질로 코팅된 후지 사과는 상온에서 20일 동안은 control에 비하여 약간의 색도의 증가를 보였으나, 그 후 60일 동안은 색도의 증가를 보이지 않았다. 그러나 냉장 보관한 control 후지 사과에 비하여 색도의 증가가 관찰되었다. 대두 단백질 코팅제가 사과의 색도 변화를 방지하는 효과를 가졌으나, 저장 온도가 색도의 변화에 더욱 큰 영향을 미침을 알 수 있었다. 대두 단백질로 코팅된 golden delicious는 상온에서60일 동안 보관하였을 경우, 사과표피의 색도 변화를 현저히 지연시킴을 확인하였다. 또한 control과 비교하여 성공적으로 사과에 코팅하였으며, 상온에서 보관하여을 때 사과의 품질을 30일 이상 연장하는 효과를 관찰하였다. 이들 결과로부터 대두단백질 필름이 과일 등의 포장제로서 이용할 가능성을 확인하였다.

• 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.