Influence of genetic background, growth latitude and bagging treatment on phenolic compounds in fruits of commercial cultivars and wild types of apples (Malus sp.)

Abstract

<p>Phenolic compounds in apples 17 cultivars (<a></a><a><i>Malus domestica</i></a><i> </i>Borkh.) and 3 wild forms (<i>Malus </i>sp.) were analyzed to study the impact of genetic background, growth site, and fruit bagging. <a></a><a>The impact of altitude was studied in nine cultivars by analyzing fruits collected from orchards at three altitudes. Procyanidin B2 (71–628 </a>mg/g fresh weight), (−)-epicatechin (35–357 mg/g), and chlorogenic acid (28–563 mg/g) were always the three most abundant phenolic compounds in the apple samples studied, except for the cultivar ‘Qinguan’, which had a very low content of (−)-epicatechin (13 mg/g) and procyanidin B2 (8 mg/g). The wild apples of <i>M. prunifolia </i>(Willd.) Borkh<i> </i>were 5-times richer in epicatechin (278 mg/g) and procyanidin B2 (628 mg/g) than the commercial cultivars of <i>M. domestica </i>Borkh (86 and 54, respectively). Among the commercial cultivars, ‘Qinguan’ had the highest level of chlorogenic acid but the lowest content of flavan-3-ols, whereas ‘Liuyuehong’ was characterized by the highest content of quercetin glycosides. Procyanidin B2, and (−)-epicatechin correlated negatively, while other phenolics positively, with altitude. The response of phenolic compounds<a></a><a> to altitude variation </a>depended on latitude variation and genetic backgrounds. Bagging treatment reduced the contents of most phenolic compounds, with impact of cultivars and length of re-exposure before harvest. This is also the first report on phenolic compounds in several important new cultivars, adding new knowledge on the compositional characteristics of global apple resources.</p>