Chemical Composition of Maize Germs Separated in the Manufacture of Cornstarch

옥수수전분 제조공정의 부산물인 maize germ의 지질 및 아미노산 조성

  • Cho, Sung-Hwan (Department of Food Science and Technology, Gyeongsang National University) ;
  • Kim, Ze-Uook (Department of Food Technology, Seoul National University) ;
  • Choi, Jong-Duck (Department of Food Science and Technology, Gyeongsang National University)
  • Published : 1986.03.30

Abstract

This study was conducted to research the industrial utilizaion of the maize germs separated in the manufacture of the cornstarch. The maize germs contained crude protein (25.3%) and crude fat (19.2%), with the 512 Kcal/100g of determined food energy values. It was found to have the valuable amounts of essential minerals, such as the content of calcium and phosphorus were low (53.0, 12.3mg%), while those of potassium (495.4mg%), magnesium (95.0mg%), zinc (48.3ppm) and manganese (45.2ppm) were plentiful. It was noted that the iodine value was 44.0, saponification value 292.3, acid value 1.5 and peroxide value about 3.3. The lipid fractions obtained by silicic acid column chromatography were mainly composed of neutral lipid, whereas, the contents of glycolipid and phospholipid were scarcely. The major fatty acids in total lipids were linoleic $(60{\sim}62.5%)$, oleic $(20{\sim}22.5%)$ and palmitic $(10{\sim}13.5%)$ acids. The content of the unsaturated fatty acids was more predominant than that of the saturated fatty acids. The content of the insoluble proteinous nitrogen (32.5%) was the most abundant. whereas, the contents of soluble proteinous nitrogen (12.7%) and peptide proteinous nitrogen (3.3%) were low. The major amino acids of the maized germs were glutamic, glycine, alanine and aspartic. It has been identified by the SDS-disc electrophoresis that the protein of maized germs had $5{\sim}6$ bands. Compared with standard substances, the molecular weight of the main protein was estimated to be $14,500{\sim}24,500$.

옥수수전분을 제조하는 과정에서 얻어지는 부산물의 산업적 이용과 공장 폐기물로 인한 환경오염을 최소화시키기 위한 기초자료를 얻기 위하여 옥수수를 파쇄하고 비중의 차로 전분부와 분리하여 모아지는 배아함유 폐기물의 조성분을 분석 정량하여 얻은 결과는 다음과 같다. 1. 일반성분으로 조단백질이 25.3%, 조지방이 19.2%로 나타났으며 시료 100g당 열량은 512kca1로 우수하였다. 2. 무기성품의 함량은 Ca, P이 비교적 낮았으며, K, Mg, Zn, Mn은 높은 값을 나타내었다. 3. 유지의 화학적 특성으로는 요오드가는 44.0 검화가 292.3, 산가 1.5, 과산화가 3.3이었으며 종자나 배아의 지방질 특성과 비슷하였다. 4. Silicic acid column chromatography에 의하여 분획된 지질은 대부분 중성지질 이었으며 다음으로 당지질, 인지질 순이었다. 5. 전지질, 유리지질 및 결합지질의 주요 지방산은 linoleic$(60{\sim}62.5%)$, oleic$(20{\sim}22.5%)$ 및 palmitic acid$(10{\sim}13.5%)$이었으며 불포화지방산이 포화지방산 보다 훨씬 많았다. 6. 질소화합물은 불용성 단백태질소함량이 32.5%로 가장 많고, 수용성 단백태질소 12.7% 및 peptide태 질소화합물은 3.3%로 적은 함량을 보였다. 7. 단백질의 주요 amino산은 glutamic, glycine, alanine 및 aspartic acid등 이었으며 곡류에 결핍되기 쉬운 lysine을 포함한 필수아미노산도 고루 함유되어 있었다. 8. SDS-disc electrophoresis 결과 $5{\sim}6$개의 단백질 band를 확인하였으며, $14,500{\sim}24,500$ 정도의 분자량을 가진 단백질이 주종을 이루고 있음을 알 수 있었다.

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