Analysis of Volatile Flavor Substances in Different Leaf Positions of Mulberry Leaves Using HS-SPME-GC-MS Combined with GC-O

To investigate the distribution of the 'grassy flavor' in mulberry leaves, the study focused on the 'Guangdong Mulberry No.11' cultivar, which was widely grown in the southern region of China. Analyzing the volatile components of different leaf positions (mulberry buds, 1~3 leaf positions, and 4~6 leaf positions) using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry olfactometry. Principal component analysis was performed to further analyze these volatile components. Results showed that 38 different volatile flavor substances in mulberry leaves at different positions were detected. Among these, 14 volatile flavor components were detected in all samples, while 24 were specific to different samples. Specifically, mulberry buds contained 24 volatile flavor components, 1~3 leaf positions contained 28 volatile flavor components, and 4~6 leaf positions contained 23 volatile flavor components. Interestingly, aldehydes were found to be the predominant volatile flavor substances in mulberry leaves at different positions. They contribute significantly to the overall flavor of mulberry leaves. Notably, (E)-2-hexenal, which was known for its ''grassy flavor'', was found to be the most abundant aldehyde in leaves at different positions. It was considered one of the characteristic components contributing to the ''grassy flavor'' of mulberry leaf. This study analyzed the flavor components among different leaf positions using the flavor intensity method and the flavor profile method. The removal of (E)-2-hexenal was found to be crucial for improving the flavor of mulberry leaf food. These findings would serve as a reference for selecting materials for mulberry leaf food.