Navarro Mirtha, Moreira Ileana, Arnaez Elizabeth, Quesada Silvia, Azofeifa Gabriela, Vargas Felipe, Alvarado Diego, Chen Pei
Department of Chemistry, University of Costa Rica (UCR), Rodrigo Facio Campus, San Pedro Montes Oca, San Jose 2060, Costa Rica.
Department of Biology, Technological University of Costa Rica (TEC), Cartago 7050, Costa Rica.
Foods. 2018 Jan 30;7(2):15. doi: 10.3390/foods7020015.
The phenolic composition of skin and flesh from apples (Anna cultivar) and plums (satsuma cultivar) commercial cultivars in Costa Rica, was studied using Ultra Performance Liquid Chromatography coupled with High Resolution Mass Spectrometry (UPLC-DAD-ESI-MS) on enriched-phenolic extracts, with particular emphasis in proanthocyanidin and flavonoids characterization. A total of 52 compounds were identified, including 21 proanthocyanidins ([(+)-catechin and (-)-epicatechin]) flavan-3-ols monomers, five procyanidin B-type dimers and two procyanidin A-type dimers, five procyanidin B-type trimers and two procyanidin A-type trimers, as well as one procyanidin B-type tetramer, two procyanidin B-type pentamers, and two flavan-3-ol gallates); 15 flavonoids (kaempferol, quercetin and naringenin derivatives); nine phenolic acids (protochatechuic, caffeoylquinic, and hydroxycinnamic acid derivatives); five hydroxychalcones (phloretin and 3-hydroxyphloretin derivatives); and two isoprenoid glycosides (vomifoliol derivatives). These findings constitute the first report of such a high number and diversity of compounds in skins of one single plum cultivar and of the presence of proanthocyanidin pentamers in apple skins. Also, it is the first time that such a large number of glycosylated flavonoids and proanthocyanidins are reported in skins and flesh of a single plum cultivar. In addition, total phenolic content (TPC) was measured with high values observed for all samples, especially for fruits skins with a TPC of 619.6 and 640.3 mg gallic acid equivalents/g extract respectively for apple and plum. Antioxidant potential using 2,2-diphenyl-1-picrylhidrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) methods were evaluated, with results showing also high values for all samples, especially again for fruit skins with IC of 4.54 and 5.19 µg/mL (DPPH) and 16.8 and 14.6 mmol TE/g (ORAC) respectively for apple and plum, indicating the potential value of these extracts. Significant negative correlation was found for both apple and plum samples between TPC and DPPH antioxidant values, especially for plum fruits ( = -0.981, < 0.05) as well as significant positive correlation between TPC and ORAC, also especially for plum fruits ( = 0.993, < 0.05) and between both, DPPH and ORAC antioxidant methods ( = 0.994, < 0.05).
采用超高效液相色谱联用高分辨率质谱法（UPLC-DAD-ESI-MS）对哥斯达黎加商业栽培品种苹果（安娜品种）和李子（萨摩蜜柑品种）的果皮和果肉中的酚类成分进行了研究，重点对原花青素和黄酮类化合物进行了表征。共鉴定出52种化合物，包括21种原花青素（[（+）-儿茶素和（-）-表儿茶素]）黄烷-3-醇单体、5种原花青素B型二聚体和2种原花青素A型二聚体、5种原花青素B型三聚体和2种原花青素A型三聚体，以及1种原花青素B型四聚体、2种原花青素B型五聚体和2种黄烷-3-醇没食子酸酯）；15种黄酮类化合物（山奈酚、槲皮素和柚皮素衍生物）；9种酚酸（原儿茶酸、咖啡酰奎尼酸和羟基肉桂酸衍生物）；5种羟基查耳酮（根皮素和3-羟基根皮素衍生物）；以及2种异戊二烯糖苷（vomifoliol衍生物）。这些发现首次报道了单一李子品种果皮中如此大量且多样的化合物以及苹果皮中原花青素五聚体的存在。此外，这也是首次在单一李子品种的果皮和果肉中报道如此大量的糖基化黄酮类化合物和原花青素。此外，还测定了总酚含量（TPC），所有样品的值都很高，尤其是水果皮，苹果和李子的TPC分别为619.6和640.3毫克没食子酸当量/克提取物。采用2,2-二苯基-1-苦基肼基（DPPH）和氧自由基吸收能力（ORAC）方法评估了抗氧化潜力，结果表明所有样品的值也很高，尤其是水果皮，苹果和李子的IC分别为4.54和5.19微克/毫升（DPPH）以及16.8和14.6毫摩尔TE/克（ORAC），表明这些提取物具有潜在价值。在苹果和李子样品中，TPC与DPPH抗氧化值之间均存在显著负相关，尤其是李子果实（= -0.981，<0.05），TPC与ORAC之间也存在显著正相关，同样尤其是李子果实（= 0.993，<0.05），以及DPPH和ORAC抗氧化方法之间（= 0.994，<0.05）。
