Using fluorescence spectra to quantitatively evaluate the constituent content and functionality of hydroponically grown <i>Fragaria × ananassa</i>

Using fluorescence spectra to quantitatively evaluate the constituent content and functionality of hydroponically grown <i>Fragaria × ananassa</i>Hidemichi Sano, Satoru Kawaguchi, Toshifumi Iimori, Masahiro Kuragano, Kiyotaka Tokuraku, and Koji Uwai*Graduate School of Engineering, Muroran Institute of Technology, 27-1 Mizumoto-cho, Muroran, Hokkaido 050-8585, Japan<br>e-mail addressHidemichi Sano: [e-mail] Kawaguchi: skawaguchi@ muroran-it.ac.jpToshifumi Iimori: [e-mail] Kuragano: [e-mail] Tokuraku: [e-mail] Uwai: [e-mail]<b>*</b>Correspondence: [e-mail];Tel.: [phone]<br><b>Abstract:</b> Strawberry leaves contain polyphenolic compounds such as elagitannins and flavonoids and are thought to possess antioxidant and amyloid-β (Aβ) aggregation inhibitory properties. However, strawberry leaves are usually discarded because their functional components vary with growth stages and environmental factors, and a method that immediately evaluates such functional strawberry leaf components in the field has not yet been developed. In this study, the fluorescence spectra obtained by irradiating strawberry leaves with excitation light were used to analyze strawberry leaves during hydroponic cultivation. Standard methods that assess the functional components (chlorophyll, total polyphenol and flavonoid content, ellagic acid, ferulic acid, naringenin) and functionality (free radical–scavenging activity, ferric reducing antioxidant power, oxygen radical absorptivity, and Aβ aggregation inhibition activity) of plants were performed. The correlations between fluorescence spectra and these parameters were analyzed using spectral indices analyses. The correlation between each spectral index and component amount and functionality of the obtained predictive model was 0.84 ≥ R ≥ 0.61. This new method facilitates the simultaneous and nondestructive prediction of both component content and functionality of strawberry leaves and allows the determination of optimal strawberry leaves for utilization as a source of functional foods and medicinal material.

利用荧光光谱定量评估水培草莓（*Fragaria × ananassa*）的组分含量与功能特性

作者：Hidemichi Sano、Satoru Kawaguchi、Toshifumi Iimori、Masahiro Kuragano、Kiyotaka Tokuraku、Koji Uwai*
单位：日本北海道室兰市水元町27-1 室兰工业大学大学院工学研究科，邮编050-8585

电子邮箱：
Hidemichi Sano：[e-mail]
Satoru Kawaguchi：[e-mail]
Toshifumi Iimori：[e-mail]
Masahiro Kuragano：[e-mail]
Kiyotaka Tokuraku：[e-mail]
Koji Uwai：[e-mail]
*通讯作者：[e-mail]；电话：[phone]

<b>摘要：</b>草莓叶片含有鞣花单宁、黄酮类等多酚化合物，被认为具有抗氧化及抑制淀粉样β蛋白（amyloid-β, Aβ）聚集的特性。然而，草莓叶片的功能组分随生长阶段与环境因素发生显著变化，因此通常被废弃；目前尚未开发出可在田间快速评估草莓叶片功能组分的方法。本研究利用激发光照射草莓叶片所获得的荧光光谱，对水培栽培过程中的草莓叶片展开分析。本研究采用标准方法测定了草莓叶片的功能组分（叶绿素、总多酚与总黄酮含量、鞣花酸、阿魏酸、柚皮素）与功能特性（自由基清除活性、铁还原抗氧化能力、氧自由基吸收能力及Aβ聚集抑制活性）。通过光谱指数分析法，探究了荧光光谱与上述各参数之间的相关性。所得预测模型中，各光谱指数与组分含量及功能特性的相关系数R介于0.61至0.84之间。该新方法可实现草莓叶片组分含量与功能特性的同步无损预测，有助于筛选出适宜作为功能食品与药用原料的优质草莓叶片。