Formation and Properties of Corn Zein Coated ${\kappa}-Carrageenan$ Films

Corn Zein을 코팅한 카라기난 필름의 제조 및 특성

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).

Corn zein을 코팅한 carrageenan복합필름을 미리 제조한 carrageenan필름을 polyethylene glycol (20% (w/w) of CZ)과 glycerol (24% (w/w) of CZ)을 함유하는 corn zein 용액(10, 20 and 30% in 95% ethyl alcohol)에 침지하여 제조하였다. 각 필름에 대하여 수증기투과도, 수분용해도, 팽윤도, 인장강도, 연신도, 열접착강도 및 색도를 측정하였다. carrageenan필름의 수증기 투과도는 corn zein 용액의 농도가 증가할수록 유의적인 차이(p<0.05)를 나타내며 감소하였다. 필름의 수분 용해도와 팽윤도는 corn zein 용액의 농도가 증가할수록 직선적으로 감소하였으며, 인장강도 역시 코팅용액의 농도에 대하여 직선적인 감소를 나타냈다. 코팅용액의 농도에 관계없이 모든 코팅필름은 열접착특성을 갖는것으로 나타내었으며, 이들의 열접착강도는 corn zein 필름의 약 절반에 미달하는 수준이었다. corn zein으로 코팅을 함으로 필름의 색도의 변화를 나타냈는데 이는 황색도(Hunter b-value)의 증가에 기인하였다.