Department of Analytical Chemistry, Annex C-3, Campus of Rabanales, University of Córdoba, Córdoba, Spain.
University of Córdoba Agrifood Excellence Campus, Córdoba, Spain.
J Sci Food Agric. 2019 Feb;99(3):1020-1028. doi: 10.1002/jsfa.9266. Epub 2018 Sep 10.
Citrus fruits possess a high content of bioactive compounds whose changes during fruit maturation have not been studied in depth. Fruits were sampled from week 1, after fruit onset (7 days after flowering), to week 14. Volatile compounds isolated by headspace-solid-phase microextraction and polar extracts from all samples were analyzed by gas chromatography-mass spectrometry.
The relative abundance of 107 identified metabolites allowed differences among samples at different stages of fruit growth to be established. Principal component analysis showed a clear discrimination among samples, and analysis of variance revealed significant differences in 94 out of the 107 metabolites. Among total volatiles, monoterpenes increased their relative abundance from 86% to 94% during fruit growth, d-limonene, γ-terpinene and β-pinene being the most abundant; conversely, sesquiterpenes decreased from 11.5% to 2.8%, β-bisabolene and α-bergamotene being the most concentrated. Sugars, in general, exhibited a gradual increase in abundance, reaching a maximum between weeks 9 and 12. Citric and malic acids, representing approximately 90% of the total identified carboxylic acids, reached a maximum concentration at commercial maturity (week 14).
Of the 107 tentatively identified metabolites during Persian lime growth, sugars, carboxylic acids, and volatiles were those that experienced more significant changes and more clearly created differences among fruit growth stages. © 2018 Society of Chemical Industry.
柑橘类水果含有丰富的生物活性化合物，但其在果实成熟过程中的变化尚未得到深入研究。本研究从花后第 7 天（果实起始后第 1 周）到第 14 周，每周采集果实样本。采用顶空固相微萃取法分离挥发性化合物，用气相色谱-质谱法分析所有样品的极性提取物。
107 种鉴定代谢物的相对丰度可确定果实生长不同阶段样品之间的差异。主成分分析表明样品间存在明显差异，方差分析显示 107 种代谢物中有 94 种存在显著差异。在总挥发性化合物中，单萜类化合物的相对丰度从果实生长的 86%增加到 94%，其中柠檬烯、γ-萜品烯和β-蒎烯含量最高；相反，倍半萜类化合物从 11.5%减少到 2.8%，β-香叶烯和α-罗勒烯含量最高。总的来说，糖的含量逐渐增加，在第 9 周到第 12 周之间达到最大值。柠檬酸和苹果酸约占鉴定出的羧酸总量的 90%，在商业成熟时（第 14 周）达到最高浓度。
在莱檬生长过程中，107 种鉴定的代谢物中，糖、羧酸和挥发性物质的变化最为显著，更能清楚地反映果实生长阶段的差异。 © 2018 英国化学学会。
