Analysis of Volatile Aroma Components in Grains of High Quality Edible Corn

Mature corn grains is an important food ration for residents in our country, but its edible flavor quality was rarely reported. The volatile organic components (VOCs) in whole grain powder with different treatment of 5 high-quality yellow grain maize varieties were detected with gas chromatography-mass spectrometry (GC-MS), the results showed that a total of 101 species of VOCs were identified, but only 60~70 species were found in a single variety. These VOCs could be divided into 12 categories, of which, the number of esters, alkanes and ketones were more, followed by alcohols, aldehydes and amides. When the composition of VOCs were analyzed, it was also found that there were about 20 species of components with high content at the level of over 10⁶ peak area, which constituted 80% of the total volatile substances content, in these high content components, 13 were co-owned which were present in all samples, and 4~16 were specific which varied among varieties. There were two species of high content components at the level of 10⁷ peak area, n-dodecane and tert-butanol were identified, which were considered to be important volatile substances in corn. The detection results also showed that the relative total content of VOCs in the samples distributed from 36.660 to 68.001 mg/kg. When they were compared each other, it was also found that the total content of VOCs was significantly different among varieties and samples, including different storage time and packages. The content of aroma substances in newly harvested grains was the highest. The ears or grains was stored naturally 1 year, its VOCs lost about 1/5. While the whole powder was stored naturally 1 year, its VOCs lost nearly a third. But the powder being stored in vacuum bags and under the low temperature 3 years, the loss of VOCs was slightly. These results suggested that the aroma substances content in corn was a variety characteristic. Excellent varieties and special production areas could effectively increase the kinds and the content of aroma substances in grains. Storage time and storage conditions could significantly affect the quality of aroma. Storage under the conditions of low temperature and vacuum could effectively maintain the quality of aroma. These results provided important reference data for quality evaluation of high quality edible corn.