Study of polyphenols, antioxidant capacity and minerals for the valorisation of ancient apple cultivars from Northeast Italy

Abstract

Nutritional properties and quality of apple fruits can be related to presence of secondary metabolite contents such as phytochemicals and mineral elements. In this paper, eight polyphenols, four major minerals (Na, K, Mg, Ca), total phenolic content and antioxidant capacity were determined in fourteen ancient apple cultivars grown in Friuli Venezia Giulia (Northeast Italy) to highlight their nutraceutical properties. Both apple peel and pulp were examined separately and results were compared to those of six widespread commercial cultivars using principal component analysis. Ancient apples had much higher content in healthful compounds with respect to commercial varieties, particularly in the peel. Ancient cultivars showed a superior antioxidant capacity in peel (3- to 9- fold) and in pulp (2- to 5-fold) compared to commercial cultivars, with a good correlation with total phenolic content (R = 0.83 in peel and 0.69 in pulp). The polyphenols that mostly characterized the ancient apples pulp were catechins and flavonols. Regarding macro elements, K and Mg content were higher in ancient cultivars, while Na and Ca showed no significant differences. In the perspective of a sustainable economic and social development of local agricultural realities, these results contribute to the valorisation of ancient local apple cultivars as invaluable reservoir of genetic biodiversity to be promoted as functional food or exploited in breeding novel apple hybrids with high nutraceutical properties and better resistance to parasites.

Profiling of Phenolic Compounds and Triterpene Acids of Twelve Apple (Malus domestica Borkh.) Cultivars

“…The concentration of quercetin found in the apples ranged between 1.10–11.61 mg/100 g DW with higher amounts for Beliy Naliv and Spartan cultivars and lowest amounts for Renet Simerenco and Richard cultivars. Rutin was a minor component among the other flavonoids, with highest concentration for Beliy Naliv, Montuan and Cretesc cultivars, being consistent with the literature [ 27 , 29 ].…”

“…The amounts of (-)-epicatechin determined in 14 ancient apple cultivars from Friuli Venezia Giulia (Italy) and six commercial apple cultivars varied from 9.10 to 85.39 mg/100 g of peel (FW) and from 7.12 to 27.06 mg/100 g of pulp (FW), while (+)-catechin varied from 3.53 to 20.20 mg/100 g in peel (FW) and from 4.21 to 16.51 mg/100 g of pulp (FW) [ 27 ]. Bondonno et al reported 10.93 mg (-)-epicatechin/100 g DW (whole apple) for the Golden Delicious apple cultivar harvested in Western Australian in 2015 season [ 28 ], while Preti et al reported for Golden Delicious the following values: 31.00 mg (-)-epicatechin/100 g and 10.27 mg (+)-catechin/100 g of apple peel (FW) and respectively, 7.49 mg (-)-epicatechin/100 g and 4.21 mg/100 g of apple pulp (FW) [ 27 ].…”

The Perspective of Croatian Old Apple Cultivars in Extensive Farming for the Production of Functional Foods

“…Preti and Tarola [ 40 ] recently evaluated fourteen ancient apple cultivars grown in northeast Italy to investigate their nutraceutical properties comprising polyphenols, antioxidant capacity, as well as four major minerals (Na, K, Mg, Ca) in comparison to commercial cultivars. All the analyses were performed on apple peel and pulp, separately.…”

Metabolomic Profiling and Antioxidant Activity of Fruits Representing Diverse Apple and Pear Cultivars

“…The composition of fruits in terms of specialized metabolites depends on both genetic and environmental factors, although the former generally has a stronger effect. There are up to 3000 apple varieties and 2000 pear varieties worldwide, but only a few of these are cultivated commercially, restricting the choice for consumers [ 4 , 35 ]. The continual strong selection pressure imposed to breed elite cultivars with visually attractive and delicious fruits that withstand long storage periods [ 36 , 37 ] has reduced the content of bioactive compounds, including polyphenols [ 22 , 23 , 38 , 39 ].…”

“…Our results are in broad agreement ( Supplementary Table S1 ). Another study reported the chlorogenic acid content of Royal Gala, Golden Delicious and Fuji apple skins as ~12, ~6 and ~16 mg/100 g fw, and the same varieties accumulated ~1.4, ~0.8 and ~1.62 mg/100 g fw of phloridzin [ 35 ]. Compared to these regular cultivars, the analysis of nine ancient apple varieties revealed that the chlorogenic acid content was three times higher (~28 mg/100 g fw) in variety Dal Doc, and that the phloridizin content ranged from twice as high (~3 mg/100 g fw in variety Limoncei) to 10-fold higher (~14 mg/100 g fw in variety Di Corone) [ 35 ].…”