Extraction Conditions and Quality Stability of Carotenoprotein from Krill Processing Waste by Proteolytic Enzymes

크릴 가공폐기물을 이용한 Carotenoprotein의 추출조건 및 품질안정성에 관한 연구

The purpose of this paper is to develop a colorant from krill, Euphausia superba, process wastes for use in food products. Carotenoproteins were extracted from preboiled krill processing offal(PKPO) and raw frozen krill processing offal(RKPO) with the aid of proteolytic enzymes. The long-term stability of the astaxanthin associated with the carotenoprotein by the addition of pretense inhibitor and antioxidant to the product were also investigated. Total astaxanthin contents of PKPO and RKPO were $35.1mg\%,\;22.1mg\%$ and those in carotenoproteins were $98.6mg\%,\;61.9mg\%$, respectively. The chitin contents of PKPO and RKPO were $6.9\%,\;4.5\%$, however, those of carotenoproteins were not determined. When $0.5\%$ trypsin was added to the extraction medium containing 0.5M $Na_3EDTA$ at $4^{\circ}C,\;74\%$ of astaxanthin and $83\%$ of the protein of PKPO were recovered as carotenoprotein in 24hrs. The amino acid profile in carotenoprotein was mainly composed of glutamic acid, methionine, aspartic acid and isoleurine. Their contents amounted to about 40% of the total amino acids, followed by alanine, phenylalanine, Iysine, leucine, threonine and tyrosine in that order, with a small amount of cysteine and tryptophan. The levels of essential amino acids were high as much as $38.3\%\~43.6\%$ of the total amino acids. The maximum observance of the carotenoid fraction from krill processing offal and from carotenoprotein was 469nm in petroleum ether. The separated components of carotenoprotein by TLC had Rfs $0.20\~0.23\;0.56\~0.60$ and $0.88\~0.91$. The carotenoids were comprised of astaxanthin, astaxanthin monoester and asthaxanthin diester in $25\~30\%\;,35\~40\%$and $40\~45\%$, respectively. The loss of carotenoids in the carotenoprotein can be prevented by the addition of pro-tease inhibitor(trasylol) and antioxidant(BHT) below $4^{\circ}C$.

크릴가공시 부산물로 얻어지는 잔사를 보다 효율적으로 이용하기 위하여 크릴가공 잔사로부터 carotenoprotein을 추출하여 이를 식품착색료로 이용할 목적으로 호소를 이용한 carotenoprotein의 추출조건 및 품질안정성에 대하여 검토하였다. 크릴가공 잔사중 총 astaxanthin함량은 자숙크릴 잔사 및 생동결 크릴 잔사에서 각각 $35.1mg\%,\;22.1mg\%$ 였으며, $98.6mg\%,\;61.9mg\%$였다. Chitin함량은 크릴가공 잔사인 자숙크릴과 생동결크릴에서 각각 $6.9\%,\;4.5\%$였으나 carotenoprotein에서는 검출되지 않았다. Trypsin이 carotenoprotein추출에 가장 효과적이었으며, papain, pepsin, protease는 거의 효과가 나타나지 않았다. Trypsin 첨가농도 $0.5\%$, 반응온도 $4^{\circ}C$에서 24시간 분해하였을 때 단백질 및 carotenoid의 회수율은 자숙시료가 각각 $83\%,\;74\%$로 가장 좋았다. 생동결크릴의 경우는 자숙크릴에 비해 단백질 및 carotenoid 회수율이 다소 떨어졌다. Carotenoprotein의 아미노산조성중 glutamic acid 와 aspartic acid의 함량이 가장 많았으며 필수 아미노산함량도 전체 아미노산의 $38.3\%\~43.6\%$를 차지하였다. Carotenoprotein중의 carotenoid는 TLC분석에 의해 astaxanthin, astaxanthin monoester, astaxanthin diester로 분리되었으며, 이들의 상대량은 각각 $25\~30\%\;,35\~40\%\;40\~45\%$였다. Carotenoprotein의 안정성은 저온($-20^{\circ}C\;4^{\circ}C$)일수록 안정하였으며, BHT와 protease inhibitor인 trasylol을 동시에 가한 것이 BHT와 trasylol만을 단독으로 가한 것보다 안정성이 좋았다.