Influence of maturity on volatile production and chemical composition of fruits of six apricot cultivars
AbstractThe fruits of six apricot cultivars were chemically analysed at two distinct stages of maturity, first when ready for picking by conventional commercial criteria, and again after another 6 days of maturation on the tree. Firmness, levels of soluble solids (SS), organic acids (citric and malic acid), sugars (sucrose, fructose and glucose), respiration rates and the production of ethylene and other volatile compounds were measured. Forty-five volatile compounds, including 12 alcohols, 10 aldehydes. 2 ketones, 10 esters, 7 terpenes, 3 lactones and I hydrocarbon were sampled by head space SPME and identified by GC-MS. The chemical composition of the non-volatile fraction (soluble solids and organic acids) exhibited only minor differences. insufficient to differentiate between the apricot cultivars or to make any meaningful judgement of the degree of maturity. Some variation between the cultivars in the respiration rate and production of ethylene was observed. However, using a stepwise logistic regression analysis, chemicals were identified among the volatile compounds which allowed the differentiation of fruits at the two different stages of maturity. In addition to the results of physical tests of firmness using standard penetration methods, differences in the degree of fruit maturation were clearly indicated by the levels of volatiles such as trans-2-hexen-1-ol, 2-methylbutylacetate, butyl-2-methylbutyrate, 6-methyl-5-heptene-2-one, acetophenone and γ-octalactone. Principal component analysis (PCA) confirmed the development of significant differences between each of the 6 apricot cultivars over the six day period of extra maturation on the tree, as each cultivar developed its own specific chemical signature. Moreover, this varietal character, which plays such an important part in determining overall attractiveness to the consumer, was only seen in fruits picked at the later stage of maturity.
From Volume 92 (2019) on, the content of the journal is licensed under the Creative Commons Attribution 4.0 License. Any user is free to share and adapt (remix, transform, build upon) the content as long as the original publication is attributed (authors, title, year, journal, issue, pages) and any changes are labelled.
The copyright of the published work remains with the authors. If you want to use published content beyond what the CC-BY license permits, please contact the corresponding author, whose contact information can be found on the last page of the respective article. In case you want to reproduce content from older issues (before CC BY applied), please contact the corresponding author to ask for permission.