Macchioni Valentina, Picchi Valentina, Carbone Katya
CREA-Research Centre for Olive, Fruit and Citrus Crops, Via di Fioranello 52, 00134 Rome, Italy.
CREA-Research Centre for Engineering and Agro-Food Processing, Via G. Venezian 26, 20133 Milan, Italy.
Plants (Basel). 2021 Dec 29;11(1):99. doi: 10.3390/plants11010099.
In hop cultivation, one-third of the crop is a valuable product (hop cones), and two-thirds is unexploited biomass, consisting mainly of leaves and stems, which, in a circular economy approach, can be recovered and, once stabilized, supplied to industrial sectors, such as cosmetics, pharmaceuticals and phytotherapy, with high added value. In this regard, this study aimed to investigate the effects of two different drying methods: oven drying (OD) at 45 °C and freeze-drying (FD), on the overall nutraceutical profile (i.e., total phenols, total flavans and total thiols), pigment content (i.e., carotenoids and chlorophylls) and the antioxidant potential of leaves from five different varieties grown in central Italy. Moreover, attenuated total reflectance infrared (ATR-FTIR) spectroscopy was applied to dried leaf powders to study the influence of both the variety and treatment on their molecular fingerprints. The spectral data were then analyzed by principal component analysis (PCA), which was able to group the samples mainly based on the applied treatment. Considering the overall phytochemical profile, FD appeared to be the most suitable drying method, while OD provided higher carotenoid retention, depending on the genotype considered. Finally, unsupervised chemometric tools (i.e., PCA and hierarchical clustering) revealed that the two main clusters contained subclusters based on the drying treatment applied; these subgroups were related to the susceptibility of the variety to the drying conditions studied.
在啤酒花种植中，三分之一的作物是有价值的产品（啤酒花球果），三分之二是未开发的生物质，主要由叶子和茎组成，按照循环经济的方法，可以回收利用，一旦稳定下来，就可以供应给化妆品、制药和植物疗法等高附加值的工业部门。在这方面，本研究旨在调查两种不同干燥方法：45℃烘箱干燥（OD）和冷冻干燥（FD），对意大利中部种植的五个不同品种叶子的整体营养成分（即总酚、总黄酮和总硫醇）、色素含量（即类胡萝卜素和叶绿素）以及抗氧化潜力的影响。此外，将衰减全反射红外（ATR-FTIR）光谱应用于干燥的叶粉，以研究品种和处理对其分子指纹的影响。然后通过主成分分析（PCA）对光谱数据进行分析，该分析能够主要根据所应用的处理对样品进行分组。考虑到整体植物化学特征，FD似乎是最合适的干燥方法，而OD根据所考虑的基因型提供更高的类胡萝卜素保留率。最后，无监督化学计量工具（即PCA和层次聚类）表明，两个主要聚类包含基于所应用干燥处理的子聚类；这些亚组与品种对所研究干燥条件的敏感性有关。
