Isolation and Characterization of Arrowroot Leaf Proteins

칡잎단백질(蛋白質)의 분리(分離) 및 그 성질(性質)에 관한 연구

To characterize the protein from arrowroot leaf, proteins were extracted and separated from arrowroot leaf, then its amino acid composition and functional properties were studied. Protein in arrowroot leaf was consisted of 18.5% albumin, 33.5% globulin, 34.0% glutelin, 6.2% protamine and 7.8% insoluble residues. The rates of precipitation of proteins which extracted with water, 1M NaCl, and 0.015N NaOH as a solvent were 84.7% (at pH 3.0), 76.4% (at pH 2.5) and 86.4% (at pH 4.0), respectively. The extracted proteins were separated up to about 90% by organic solvents such as ethanol and acetone at 80% concentration, Composition of arrowroot leaf protein concentrates were: $1{\sim}2%$ moisture, $59{\sim}67%$ protein, $4{\sim}8%$ ash and $5{\sim}6%$ (dialyzed concentrates) or $1{\sim}2%$ (acetone-treated ones) lipid. Main amino acids of the concentrates were aspartic acid, glutamic acid and glycine. Solubility profile of the concentrates according to pH was typical. The minimum solubility (below pH 5.0) of acetone extracted protein concentrates was lower than that of unextracted ones, whereas the reverse was true for pH value above this region. Bulk density, water and fat absorption of the concentrates were attributable to correlation to the treatment of acetone. And the bulk density of the concentrates was negatively correlative to both water and fat absorption. Emulsifying and foaming properties were not varied with the treatment of acetone.

칡잎단백질(蛋白質) 식량자원화(食糧資源化)를 위한 기초연구(基礎硏究)를 목적(目的)으로 칡잎으로부터 여러 가지 용매(溶媒)를 이용하여 단백질(蛋白質)을 추출(抽出), 분리(分離)한 후 그의 아미노산(酸) 조성(組成) 및 기능적(機能的) 특성(特性)을 검토한 결과는 다음과 같다. 용해도(溶解度)에 따른 칡잎단백질(蛋白質)은 수용성(水溶性) 단백질(蛋白質)이 18.5%, 염용해(鹽溶解) 단백질(蛋白質)이 33.5%, 알칼리 용해성(溶解性) 단백질(蛋白質)이 34.0%, protamine이 6.2%, 불용해성(不溶解性) 단백질(蛋白質)이 7.8%이었다. 증류수(蒸溜水), 1M NaCl, 0.015N NaOH의 용매(溶媒)에 의한 추출액(抽出液)의 단백질(蛋白質) 침전률(沈澱率)은 pH 3.0, 2.5, 4.0에서 가장 높다. 84.7, 76.4, 86.4% 이었으며 80%의 ethanol과 acetone의 첨가에 의해서는 약 90%가 침전(沈澱)되었다. 단백질농축물(蛋白質濃縮物)의 일반성분(一般成分)은 수분(水分) $1{\sim}2%$, 단백질(蛋白質)이 $59{\sim}67%$, 회분(灰分)이 $4{\sim}8$이었으며 지질함량에 있어서는 투석(透析)한 것은 $5{\sim}6%$, acetone 처리한 것은 $1{\sim}2%$이었다. 농축물(濃縮物)의 아미노산함량(酸含量)은 aspartic acid, glutamic acid, glycine의 순(順)으로 높았다. 농축물(濃縮物)의 용해도(溶解度)는 pH5이하에서 acetone 처리구(區)가 무처리구(區)에 비하여 낮았으며 그 이상의 pH에서는 높았다. 또 농축물(濃縮物)은 acetone 처리에 의하여 용적밀도(容積密度), 수분(水分) 및 지방흡착도(脂肪吸着度)에 상관관계를 나타내었으며 용적밀도(容積密度)에 대한 수분(水分) 및 지방흡착도(脂肪吸着度)는 반비례적이었다. 유화성(乳化性) 포립성(泡粒性)은 acetone 처리에 따라 별 차이가 없었다.