Optimization and analysis of volatile aroma components of Xiangyu wax gourd by solid phase microextraction

【Objective】 The objective of this study was to optimize the extraction process conditions of volatile aroma components in the fruit of Xiangyu wax gourd, and fully analyze the volatile aroma components in the fruit. It had important scientific significance and application prospect for in-depth study of aroma composition and further excavation of aroma quality.【Method】 The Xiangyu wax gourdfruit as the test material, using solid phase microextraction technology (SPME) -gas chromatography-mass spectrometry(GC-MS) fully extracted and identified the volatile aroma components in the fruits of Xiangyu wax gourd. The Box-Behnken method was used to optimize the preheating time, extraction time, extraction temperature and desorption time of four SPME process parameters.【Result】 The response surface test results showed that the effects of various factors on the total peak area of volatilearoma components were as follows:extraction temperature > desorption time > preheating time > extraction time. The optimal extraction conditions of SPME were as follows:6.6 min of preheating time, 62℃ of extraction temperature, 43 min of extraction time, and 4.5 min of desorption time. A total of 44 aroma substances were identified by using the above optimal solid-phase microextraction conditions, including 14 aldehydes, 10 alcohols, 4 ketones, 4 esters and 4 aromatic compounds, 3 acids and a small amount of alkynes and other substances. The main volatile aroma components were(E) -2-hexenal(83.51±2.43 μg/mL), n-hexadecanoic acid(38.56±1.24 μg/mL), 1-hexanol(38.08±1.52 μg/mL), hexanal(32.07±1.67 μg/mL), hexanoic acid(24.71±1.59 μg/mL), octadecanoic acid(17.56±0.80 μg/mL), (E) -2-nonenal(14.87±0.93 μg/mL), benzaldehyde(13.68±0.83 μg/mL).【Conclusion】 The response surface method is used to optimize the optimal extraction conditions, the main components of the candidate characteristic volatile substances of Xiangyu wax gourdare(E) -2-hexenal, n-hexadecanoic acid, 1-hexanol, hexanal, hexanoic acid, octadecanoic acid, (E) -2-nonenal, benzaldehyde.