Alterations in the Properties of Agar by ionizing Radiation

  • Lee, Su-Rae (Korea Atomic Energy Research Institute, Seoul) ;
  • Park, Sang-Ki (Korea Atomic Energy Research Institute, Seoul) ;
  • Cho, Han-Ok (Department of Food and Nautrition, Soodo Women's University, Seoul)
  • Published : 1976.09.01

Abstract

Alkali-treated red algae, Gracilaria sp. was irradiated with various doses of cobalt-60 gamma-rays and the yeild and properties of agar extracted from the seaweed were examined and compared with the quality of commercial agar powder after irradiation. Extraction yield of agar from irradiated seaweed was proportionally increased as the radiation dose was raised up to 2 Mrad whereas it tended to decrease slightly thereafter. Gelation ability, gelation point, gel hardness and specific viscosity of the agar were increased up to 1 Mrad and decreased at higher dose levels while its melting point, total nitrogen, crude ash and total sulfur decreased up to 1 Mrad level and remained unchanged thereafter. Irradiation of commercial agar powder caused remarkable decreases in the gelation ability, specific viscosity and gel hardness and slight decreases in the gelation point and melting point. The pattern of alterations in the properties of agar samples differed whether the polysaccharide was irradiated in free state or bound state in seaweed.

한천 원조인 꼬시레기를 여러 가지 선량의 코발트 60 감마선으로 조사하고 이에서 추출한 한천의 수율 및 특성을 조사하였으며 방사선조사한 한천분말의 품질과 비교하였다. 방사선조사한 원조에서의 한천의 수율은 조사선량이 2 Mrad 까지 상승됨에 따라 증가하였고 그 이상에서는 약간 감소하는 경향이었다. 한천의 젤화능력, 젤화점, 젤견고성 및 비점도는 1 Mrad까지 증가하였고 그이상에서는 감소하였으며 융점, 전질소, 조회분, 전유황 함량은 1 Mrad 까지 감소하였고 그 이상에서는 변화가 완만하였다. 시판용 한천분말의 방사선조사는 젤화능력, 비점도, 젤견고성의 급격한 감소와 젤화점, 융점의 완만한 감소를 가져왔다. 한천시료의 특성의 변화패던의 한천을 유리상태 또는 결합상태(해조중 존재형태)에서 조사하는가에 따라 달리 나타났다.

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