DYNAMIC CHANGES OF VOLATILE ESTERS DURING FRUIT DEVELOPMENT IN FRAGARIA ×ANANASSA AND F. VESCA

Esters are the biggest group of volatile compounds in Fragaria fruits and play a very important role in strawberry aroma formation. Volatiles in fruits developed 20, 24, 28, 32, 36, 40, 44, 48 and 52 days after bloom of F. ×ananassa ‘Benihoppe’ and F. vesca were detected quanlitatively and quantitatively by headspace-SPME with GC-MS. A total of 13 esters were indentified in ‘Benihoppe’, while 16 in F. vesca. Although the number and the total content of esters detected in F. vesca were obviously higher than ‘Benihoppe’ cultivar, the dynamic changing trends were similar. The number and the total content increased along with fruit developping. Ester concentration of ‘Benihoppe’ reached its peak on 52 days after bloom while that of F. vesca was the highest on 44 days. The esters existing in ‘Benihoppe’ and F. vesca were significantly different except 7 esters. Most esters appeared in the late period of fruit development and their contents became the maximum around maturity, while only hexyl acetate and ethyl hexanoate were prevalent from 20 days to 48/52 days after bloom. In ‘Benihoppe’, 1-methyl ethyl hexanoate and ethyl hexanoate were the esters with the highest concentrations. However, in F. vesca, ethyl butanoate, ethyl hexanoate, and octyl acetate had the top three concentrations. Most of the esters of ‘Benihoppe’ were described as having only fruity odor. Unlike the case of ‘Benihoppe’, nearly all of the esters in F. vesca have a noticeable floral odor in addition to a fruity note. It was indicated that differences in esters were closely related with different types of aroma between F. ×ananassa and F. vesca.