Changes of soluble solid contents and volatile flavor components of three sweet corn cultivars under different storage conditions

Objective  To clarify the change law of soluble solid contents and volatile flavor substances of sweet corn (Zea mays L. saccharata Sturt.) after harvest under different storage temperature and time, and lay a foundation for the research on the quality characteristics of sweet corn after harvest.

Method  Three sweet corn cultivars of ‘Aofulan’, ‘Wangchao’, and ‘Guangliangtian 27’ were used as materials. The soluble solid contents of three cultivars were measured by a handheld digital sugar meter, and the volatile flavor components of sween corns under normal temperature (room temperature) and low temperature (4 ℃) storage conditions were detected and analyzed by headspace solid-phase microextraction through gas chromatography-mass spectrometry. Furthermore, multivariate statistical analysis was used analyze the volatile flavor components of different cultivars.

Result  Compared with normal temperature storage, the content of soluble solid of sweet corn decreased slowly under low temperature storage. Total 58 and 59 kinds of volatile substances were detected under normal and low temperature storage conditions respectively, mainly alkanes and esters. There were certain differences in the types of volatile flavor substances among different cultivars under different storage conditions. There were the same eight volatile flavor substances among different cultivars under different storage conditions, including 3,8-dimethyldecane, 3-methylundecane, dodecane, tetradecane, 3-methylpentadecane, ethyl hexadecanoate, nonadecane and n-hexadecane. Partial least squares discriminant analysis (PLS-DA) showed that nine and ten key volatile substances with variable importance projection (VIP)>1 have been identified under normal and low temperature storage respectively. The common key volatile substance of ‘Aofulan’ under normal and low temperature storage was (+)-cycloclofalene, and that of ‘Wangchao’ was eicosane.

Conclusion  Both storage temperature and time affect the content of soluble solids and the types and contents of volatile substances in sweet corn.