Phenolic Compounds, Carotenoids and Antioxidant Activity of Flat and Standard Peach Cultivars [Prunus persica (L.) Batsch]

In recent years, a new type of peach cultivar called "flat peach" has been introduced in the peach and nectarine market. These new cultivars compared to the existing standard types, have very different characteristics. The aim of this study was to analyze some quality parameters [weight, firmness, soluble solids concentration (SSC), titratable acidity (TA)] and some bioactive compounds (polyphenols, carotenoids, total antioxidant activity) of eight cultivars of peaches and nectarines. The results showed that, regardless of the type of peach or nectarine or pulp colour (yellow or white), the flat cultivars always had more pronounced sensory and nutritional qualities. The flat cultivars were different from the standard ones because of their higher SSC (+26.7%) and lower TA (-53.7%), as well as their greater antioxidant activity, especially for nectarines (+39.4%) and greater amount of phenolic compounds, especially for those with white pulp (+63.2%). The most important phenolic compounds in flat cultivars were procyanidin, quercetin and catechin. Interesting results were also obtained regarding the carotenoids content: it was higher in the peaches than in the nectarines (+33.0%) and with respect to the colour of the pulp, higher in the yellow pulp (2.436 mu g/g dw) than in the white pulp (0.189 mu g/g dw), in both peaches and nectarines.