Changes of apple fruit volatile profiles induced by fresh bruise at early stage

Fresh bruise of apple is a major postharvest problem, which is easily ignored at early stage and can develop into more serious external bruise as the time goes on. In this study, we investigated changes of volatile organic compounds (VOCs) profile of apples with fresh bruise during 0-24 h. For this purpose, headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was used. A total of 43 aroma compounds were identified in apple, consisting of 8 carbonyl compounds, 23 esters, 5 alcohols, 5 terpenes and 2 other compounds. The data of VOCs were subjected to partial least squares discriminant analysis, which showed that 12 h might be the optimum time for apple quality maintenance after fresh bruise. The content of VOCs in bruised tissues showed a significant increase, while they were basically unchanged in healthy tissues. The content of carbonyl compounds increased during 0-24 h, in particular C6 and C9 aldehydes. The content of (3E,6E)-3,7,11-trimethyldodeca-1,3,6,10-tetraene was increased. The results of this study may help top to understand the metabolic disorder and quality maintenance after fresh bruise in apple fruits.