优质食用籽粒玉米挥发性香味物质组分分析

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

籽粒玉米是我国居民,尤其是北方居民的重要口粮,但其食用香味品质国内外鲜有报道。取样5个优质黄粒玉米品种的籽粒,磨碎成全粉,采用气相色谱-质谱联用(GC-MS)方法测定不同处理样品中挥发性物质组分和含量,结果显示,共鉴定出挥发性物质101种,单个品种60~70种,可分为12类。其中的酯、烷、酮数量较多,其次是醇、醛、酰胺等。对挥发性物质组分进行分析,发现峰面积在106水平的高含量成分20余种,其中所有品种均含有的共有成分13种,品种特有成分4~16种,这些成分构成总含量的80%以上。峰面积107水平的高含量成分2种,分别为正十二烷和叔丁醇,是籽粒玉米中重要挥发性物质。检测结果还显示,样品中挥发性物质相对总含量为36.660~68.001 mg/kg,品种间差异显著,同一品种,不同产地、不同贮藏条件含量差异也显著。新收获籽粒香气物质含量最高,籽粒自然保存1年,含量耗损约1/5,全粉自然保存1年,耗损近1/3,真空包装,损耗轻微。这些结果表明,玉米香气物质含量具品种特性,选择优良品种并在特殊地区生产,能有效提高含量;贮存时间和贮存条件显著影响玉米品质,低温真空条件贮存可有效保持香气品质。这些结果为优质食用玉米品质评价提供重要参考数据。

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.