玉米芯的营养成分分析

Analysis of the Nutritional Components of Corn Cobs

本文主要分析了甜玉米、超甜玉米、两种糯玉米煮熟前后共8个样品的玉米芯的营养成分。实验结果表明，除水分外，纤维素、淀粉是玉米芯的主要成分，其中甜玉米芯的纤维素含量最高，可达0-3g佗；糯玉米芯淀粉含量比非糯型高50％，经蒸煮之后，糊化作用导致糯玉米芯的的淀粉损失率为50％；玉米芯的多酚含量≤1．34μg／g，而黄酮的含量最高可i态到0．05mg／g；8种玉米芯的氨基酸含量基本接近，其中以谷氨酸和脯氨酸含量最高，蛋氨酸和络氨酸含量最低，熟的甜玉米芯所含的氨基酸总量最高，为14．94mg／g，必需氨基酸含量占31．88％；玉米芯中矿质元素丰富，cu含量最高，为5．61-24．23mg／g，其次则是K和Mg。

Abstract： In this paper, the contents of nutritional components of four kinds of commercially available corn cobs in Guangzhou, Guangdong province, were analyzed, including yellow sweet corns, yellow with white corns, sticky white corns and purple with white sticky corns. It was found that fiber and starch were the main components of the corn cobs. Raw sweet corn cob containsed the highest content of cellulose, up to 0.3 g/g. The starch in waxy corn cob was about twice higher than non-waxy type, but 50% starch was lost after gelatinization. The highest content ofpolyohenol was less than 1.34 μg/g while about 0.05 mg polyphenol can be acquired for only 1 g cooked corn cob. All the tested com cob had a similar amino acid composition. Among the amino acids, the glutamic acid and proline had the highest content while methioninetyrosine content was the lowest. In addition, the cooked sweet corn cob contained the highest content of total amino acids, up to 14.94 mg/g containing 31.88% essential amino acids. Corn cob was also rich in mineral elements, m which Cu showed the highest content （5.613-24.23 mg/g）, followed by element K and Mg.