ABSTRACT

While plums are widely touted for their health benefits, there is little data available on the levels of beneficial anthocyanins and other antioxidative compounds found in commercial Australian plums. As such, this study aims to provide context data on the typical levels and variation in plums available to consumers. Six commercial plum varieties were sourced from Central Queensland grocery stores, including two varieties developed and grown exclusively in Australia – Croc Egg and “King Midas” yellow plums – as well as four varieties grown both in Australia and internationally: black, Dapple Dandy, red and sugar plums. These were analyzed for antioxidants, phenolics, anthocyanins and mineral contents. Significant differences between varieties were observed in the levels of total phenolics (65–160 mg gallic acid equivalents 100 g⁻¹ on a fresh weight basis), antioxidants (cupric reducing antioxidant potential of 174–542 mg Trolox equivalents 100 g⁻¹) and anthocyanins (0.3–21.5 mg cyanidin-3-glucoside equivalents 100 g⁻¹), as well as in the flavonols quercetin (0.02–0.15 mg 100 g⁻¹) and quercetin-3-glucoside (0.21–2.87 mg 100 g⁻¹). Mid-infrared attenuated total reflectance (MIR-ATR) spectroscopy combined with principal component analysis could separate varieties based on their phytochemical composition. The findings suggest that commercially available Australian plums contain similar levels of health-benefitting compounds to those found internationally, although the levels of these compounds depend strongly on the considered variety.

摘要

尽管李子因其健康益处而广受吹捧，但关于澳大利亚商业李子中有益花青素和其他抗氧化化合物含量的数据很少。因此，本研究旨在提供消费者可获得的李子的典型含量及其变化的背景数据。昆士兰中部杂货店采购了六个商业李子品种，包括两个在澳大利亚专门开发和种植的品种-Croc Egg和“ King Midas”黄色李子-以及在澳大利亚和国际上种植的四个品种：黑色，Dapple Dandy，红色和糖李子。分析了它们的抗氧化剂，酚类，花色苷和矿物质含量。在总酚含量（65–160 mg没食子酸当量100 g^-1（以新鲜重量计），抗氧化剂（降低抗氧化电位的174–542 mg Trolox当量100 g ^-1）和花色苷（0.3–21.5 mg氰基-3-葡萄糖苷当量100 g ^-1），以及黄酮醇槲皮素（0.02–0.15 mg 100 g ^-1）和槲皮素-3-葡萄糖苷（0.21–2.87 mg 100 g ^-1）。中红外衰减全反射（MIR-ATR）光谱与主成分分析相结合可以根据植物的植物化学成分来分离它们。研究结果表明，可商购的澳大利亚李子含有与国际上相似的有益于健康的化合物，尽管这些化合物的含量在很大程度上取决于所考虑的品种。