Volatile profiling of two pear genotypes with different potential for white pear aroma improvement

Abstract

Abstract. Chinese white pear (Pyrus bretschneideri) is sweet, juicy and crispy, but not fragrant. The two pears ‘Xiang-Mian Li’ (‘XML’) and ‘Mu-Tou Su’ (‘MTS’) with fragrant and large fruits were noted recently from pear germplasm screening. Their volatile profiles were compared with those of typical white pear ‘Dang-Shan Suli’ (‘DSS’) (P. bretschneideri) and fragrant pear ‘Nan-Guo Li’ (‘NGL’) (P. ussuriensis) in this study for a better understanding the chemistry of the differences among the tested cultivars. Headspace solid phase microextraction (HS-SPME) coupled to gas chromatography–mass spectrum (GC–MS) was used for sensitive intact fruit volatile profiling while a static headspace GC–MS system was employed for accurate volatile quantification. The rank of the tested intact fruits based on detected volatile numbers and total odor active values was ‘NGL’ > ‘XML’ > ‘MTS’ > ‘DSS’. Among many detected volatiles, ethyl 2-methylbutyrate and ethyl hexanoate were the most potent and pleasant odorants from the intact fruit and fruit pulp of ‘XML’ and ‘NGL’, but not from ‘MTS’ pulp. They were identified as the most important contributors to the volatile profile variance among the tested pear fruits. Our study indicated that compared to ‘MTS’, ‘XML’ had much more intense aroma and this genotype had potential for Chinese white pear aroma improvement.