Department of Pharmaceutical Sciences, University of Florence, Via Ugo Schiff 6, 50019, Sesto Fiorentino, Firenze, Italy.
Phytochem Anal. 2013 Sep-Oct;24(5):460-6. doi: 10.1002/pca.2443. Epub 2013 May 28.
Kiwifruit contains high amounts of anti-oxidants beneficial to health. Its quality is influenced by ripening time, genotype, cultivation techniques, climate and storage conditions after harvest.
The aim of the present study was to characterise the phenolic content by HPLC methods and to evaluate the performance of a portable optical sensor (Multiplex 3), for in vivo non-destructive phenolic compound assessment in kiwifruits.
Kiwifruits peel extracts were characterised by reverse-phase (RP) HPLC with diode-array detector (DAD) and electrospray ionisation (ESI) with MS using the Zorbax SB-Aq. column from Agilent. The fluorimetric sensor method is based on the screening of fruit chlorophyll fluorescence excitation and allows the UV absorbance of intact fruit skin to be measured. The flavonol index, FLAV, was calculated as log(FRF(R)/FRF(UV)), where FRF(R) and FRF(UV) are the chlorophyll fluorescence excited with red and UV light.
Hydroxycinnamic acids, procyanidins, and quercetin glycosides were the main polyphenol classes detected by HPLC-DAD-ESI/MS in the kiwifruit skin. A good linear regression (R² = 0.88) was found between the fluorimetric sensor FLAV index and flavonol chromatographic analysis of the fruits. The FLAV index was able to detect the higher content of flavonols in sun-exposed fruits with respect to mid-shaded and shaded ones in accordance with the destructive analysis.
The fluorimetric sensor represents a rapid and non-invasive tool to: (i) monitor the flavonol accumulation in kiwifruit and to assess its quality concerning the healthy anti-oxidant properties; (ii) evaluate the effect of environmental and agronomical factors related to the fruit quality; and (iii) select fruits with the largest flavonol content, and consequently less susceptible to pathogen attack, in order to improve their storage durability.
猕猴桃含有大量对健康有益的抗氧化剂。其品质受成熟时间、基因型、栽培技术、气候和收获后贮藏条件的影响。
本研究旨在通过高效液相色谱法（HPLC）方法对酚类物质进行表征，并评估便携式光学传感器（Multiplex 3）在猕猴桃体内非破坏性酚类化合物评估中的性能。
采用反相（RP）高效液相色谱法（HPLC）-二极管阵列检测器（DAD）和电喷雾离子化（ESI）-质谱联用（MS），使用 Agilent 的 Zorbax SB-Aq 柱对猕猴桃果皮提取物进行分析。荧光传感器法基于果实叶绿素荧光激发的筛选，可测量完整果实果皮的紫外吸光度。类黄酮指数（FLAV）计算为 log(FRF(R)/FRF(UV))，其中 FRF(R)和 FRF(UV)分别为用红光和紫外光激发的叶绿素荧光。
高效液相色谱法-二极管阵列检测器-电喷雾离子化/质谱联用（HPLC-DAD-ESI/MS）在猕猴桃果皮中检测到主要的多酚类物质包括羟基肉桂酸、原花青素和槲皮素糖苷。在果实中，荧光传感器的 FLAV 指数与类黄酮的色谱分析之间存在良好的线性回归（R²=0.88）。FLAV 指数能够检测到暴露在阳光下的果实中类黄酮含量较高，而遮荫和半遮荫果实中的类黄酮含量较低，与破坏性分析结果一致。
荧光传感器是一种快速、非侵入性的工具，可用于：（i）监测猕猴桃中类黄酮的积累，评估其具有健康抗氧化特性的品质；（ii）评估与果实品质相关的环境和农艺因素的影响；（iii）选择类黄酮含量较高的果实，从而降低果实对病原体攻击的敏感性，提高其贮藏耐久性。
