花生（Arachis hypogaea L.）发芽过程中含氮物质的变化

研究花生品种“百日红”（Arachis hypogaea L.）96 h发芽过程中主要含氮物质的变化。结果表明：发芽96 h，蛋白酶活性与干种子相比增加了53.82 倍，蛋白质水解度达到15.01%；十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（sodium dodecylsulfate polyacrylamide gel electrophoresis，SDS-PAGE）显示，部分伴花生球蛋白（50～66 kD）和花生球蛋白酸性亚基（38～49.9 kD）条带消失，同时大量低分子质量蛋白（＜18 kD）条带出现；发芽对花生总氮含量没有显著影响，96 h后蛋白氮含量下降15.88%，非蛋白氮（肽氮＋氨基氮）含量显著增加（从2.84 mg/g增加为9.20 mg/g）；蛋白质中色氨酸和缬氨酸等限制性氨基酸的含量随着发芽时间的延长而增加，必需氨基酸和含硫氨基酸比例增加，必需氨基酸指数（essential amino acid index，EAAI）提高，表明发芽对花生蛋白的质量有明显的增强。

Change of Nitrogenous Compounds in Peanut (Arachis hypogaea L.) Seeds during Germination

The change of nitrogenous compounds in the seeds of peanut cultivar Bairihong (Arachis hypogaea L.) during
96 h of germination was investigated. The results showed that the protease activity of peanut seeds germinated for 96 h
was increased by 54.82 times as compared with that of ungerminated dry seeds and the degree of protein hydrolysis was
15.01% at the end of the germination period. SDS-PAGE pattern showed the partial disappearance or loss of conarachin
(50 - 66 kD) and acidic arachin (38 - 49.9 kD) together with the appearance of a series of smaller molecular weight
subunits. The total nitrogen content was not significantly altered, but the quantity of protein nitrogen fell by 15.88% with
a concomitant increase in the content of non-protein nitrogen (from 2.84 mg/g to 9.20 mg/g) after 96 h of germination.
The contents of limiting amino acids (Trp + Val), the ratios of essential amino acids and of sulfur-containing amino acids
to total amino acids and essential amino acid index (EAAI) increased with prolonged germination period, suggesting that
germination can significantly enhance the quality of peanut protein.