Effects of n-Butanol Treatment on Volatile Compounds of 'Pink Lady' Apple during Storage

Studying apple volatile compounds is of great significance because aroma composition is an important factor of apple quality. In this experiment, n-butanol treatment was used to determine the effect it has on the volatile substances of ‘Pink Lady’ apples. The 'Pink Lady' apples were used as the test material and were treated with 10 and 25 μL·L⁻¹ of the n-butanol solution respectively. The volatile compounds were extracted by organic solvent extraction and analyzed by gas chromatography-mass spectrometry (GC-MS). There were 25 volatile compounds detected over the storage period, including esters, alcohols, aldehydes, acids, and terpenes. Esters and aldehydes were the most common compounds. The types of volatile chemicals in fruits declined as storage time increased, and amyl acetate, butyl butyrate, 2-methyl-hexyl propionate, farnitol, and 2-methyl-butyrate were not discovered. The contents of amyl acetate, butyl butyrate, 2-methyl-hexyl propionate, farnesol and 2-methyl-butyric acid in 25 μL·L⁻¹ treatment group were significantly higher than those in control group and 10 μL·L⁻¹ treatment group on the 7th and 14th day of storage. The addition of n-butanol at this concentration could promote the production of volatile esters in fruits at the early stage of storage. Nineteen compounds were detected as having odor activity (OAV), of which hexyl acetate was the main aroma component of ‘Pink Lady’ apple. This study showed that n-butanol supplementation affected the production of esters in 'Pink Lady' apple fruit, and the effect of 25 μL·L⁻¹ treatment group was the most significant. Meanwhile, this study would provide a theoretical basis for the study of volatile substances in ‘Pink Lady’ apple fruit.