Changes in the Volatile Compounds and Chemical and Physical Properties of Kuerle Fragrant Pear (Pyrus serotina Reld) during Storage

Abstract

Volatiles from stored Kuerle fragrant pears (Pyrus serotina Reld) were studied using high-resolution gas chromatography and the solid-phase microextraction (SPME) method of gas chromatography/mass spectrometry (GC/MS). The dominant components were hexanal, ethyl hexanoate, ethyl butanoate, ethyl acetate, hexyl acetate, ethanol, alpha-farnesene, butyl acetate, and ethyl (E,Z)-2,4-decadienoate. By using GC-olfactometry, it demonstrated that the volatile compounds from SPME were responsible for the aroma of the Kuerle fragrant pear. The levels of sugars, organic acids, and phenolic acids in Kuerle fragrant pears were investigated using high-performance liquid chromatography (HPLC). Fructose was the dominant sugar, followed by glucose and sucrose. With increasing storage time, sucrose levels decreased; however, changes in fructose and glucose levels were not remarkable. There was a slight decrease in flesh firmness during storage. The general soluble solids concentration (SSC) declined slightly after 5 months storage. Some aroma-related volatile components increased during storage, while others decreased, especially the esters. The organic acids and phenolic acids also changed. The flavor of the Kuerle fragrant pears was affected by the change of volatile compounds and changes in chemical and physical properties.