Study of Polyphenol Profile and Antioxidant Capacity in Italian Ancient Apple Varieties by Liquid Chromatography
Safeguarding, studying and enhancing biodiversity play an important and indispensable role in re-launching agriculture. The ancient local varieties are therefore a precious resource for genetic and health improvement. In order to protect biodiversity through the recovery and valorization of autochthonous varieties, in this study we analyzed 12 samples of four ancient apple cultivars representative of Friuli Venezia Giulia, selected by local farmers who work on a project for the recovery of ancient apple cultivars. The aim of this study is to evaluate the polyphenolic profile and the antioxidant capacity that characterize the organoleptic and functional qualities of this fruit species, besides having beneficial properties for health. In particular, for each variety, the following compounds were analyzed, both in the skins and in the pulp: gallic acid, catechin, chlorogenic acid, epicatechin, caffeic acid, coumaric acid, ferulic acid, rutin, phlorizin, phloretin and quercetin to highlight any differences in the edible parts of the apple. The analysis of individual phenolic compounds was performed by High Performance Liquid Chromatography (HPLC) coupled with a diode array UV detector (DAD), the antioxidant capacity was estimated using an in vitro essay based on a Free Radical Scavenging Method and the total phenolic compounds was determined using the Folin-Ciocalteau method. From the results, it is evident that the catechins are the most present polyphenols, reaching a value of 140-200 μg/g in the pulp and of 400-500 μg/g in the skin, with the prevalence of epicatechin. Catechins and phlorizin, a dihydrohalcone typical of apples, are always contained in larger quantities in the peel. Total phenolic compounds content was positively correlated with antioxidant activity in apple pulp (r2 = 0,850) and peel (r2 = 0,820). Comparing the results, differences between the varieties analyzed and between the edible parts (pulp and peel) of the apple were highlighted. In particular, apple peel is richer in polyphenolic compounds than pulp and flavonols are exclusively present in the peel. In conclusion, polyphenols, being antioxidant substances, have confirmed the benefits of fruit in the diet, especially as a prevention and treatment for degenerative diseases. They demonstrated to be also a good marker for the characterization of different apple cultivars. The importance of protecting biodiversity in agriculture was also highlighted through the exploitation of native products and ancient varieties of apples now forgotten.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.3346716Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF
 J. Glausiusz, Apple of Eden, Saving the wild ancestor of modern apples, National Geographic, 9/5/2014
 World apple and pear association (WAPA), www.wapaassociation.org
 V. Georgiev., A. Ananga, V. Tsolova, “Recent advances and uses of grape ﬂavonoids as nutraceuticals” Nutrients vol. 6, pp. 391–415, 2014
 T. Wang, H. Long Wu, L. X. Xie, L. Zhu, Z. Liu, X. D. Sun, R. Xiao, R. Q. Yu, “Fast and simultaneous determination of 12 polyphenols in apple peel and pulp by using chemometrics-assisted high-performance liquid chromatography with diode array detection” J.Sep.Sci. vol. 40, pp. 1651-1659, 2017
 J. Boyer, R.H. Liu, “Apple phytochemicals and their health benefits” Nutr J, vol.3, pp. 5-15, 2004
 F. G. K. Vieira, G. Da Silva C. Borges, C. Copetti, P. F. Di Pietro, E. da Costa Nunes, R. Fett, “Phenolic compounds and antioxidant activity of the apple flesh and peel of eleven cultivars grown in Brazil”, Scie. Hort. Vol. 128, no.3, pp. 261-266, 2011.
 V.L. Singleton, R. Orthofer, R.M Lamuela-Raventos, “Analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteau reagent”. Methods Enzymol., vol. 299, pp. 152-178, 1999.
 P.D. Drogoudi, Z. Michailidis, G. pantelidis, “Peel and plesh antioxidant content and harvest quality of seven apple cultivars”, Scientia Hort, vol. 115, pp. 149-153, 2008.
 K. Carbone, B. Giannini, V. Picchi, R. Lo Scalzo, F. Cecchini, “Phenolic composition and free radical scavenging activity of different apple varietes in relation to the cultivar, tissue type and storage”, Food Chem., vol. 127, pp. 493–500, 2011.
 A. Francini, L. Sebastiani L “Phenolic compounds in apple (Malus × domestica Borkh.): compounds characterization and stability during postharvest and after processing”, Antioxidants, vol. 2, no. 3, pp. 181-193, 2013.
 J. Oszmiański, S. Lachowicz, E. Gławdel, T. Cebula, I. Ochmian, “Determination of phytochemical composition and antioxidant capacity of 2 old apple cultivars grown in Poland” Eur Food Res Technol vol. 244, pp. 647–662, 2018.
 L. Jakobek, A.R. Barron, “Ancient apple varieties from Croatia as a source of bioactive polyphenolic compounds” J. Food Compos. Anal., vol. 45, pp. 9–15, 2016.
 S. Kevser, S. Amasya, S. Spur, E. Spur, K. Luscious, A. Kizi, L. Golden, “Comparison of antioxidant capacity and phenolic composition of peel and ﬂesh of some apple varieties, eyda Karaman, a Esma T utem” J. Sci. Food Agric., vol. 93, pp. 867–875, 2013.
 S. Belviso, B. Scursatone, G. Re, G. Zeppa, “Novel Data on the Polyphenol Composition of Italian Ancient Apple Cultivars” Int. J. Food Prop., vol. 16, pp. 1507–1515, 2013.
 B. Lata, A. Trampczynska, J. Paczesna, “Cultivar variation in apple peel and whole fruit phenolic composition” Sci. Hortic., vol. 121, pp. 176–181, 2009.
 M Kalinowska, A. Bielawska, H. Lewandowska-siwkiewicz, W. Priebe, “Plant Physiology and Biochemistry Apples: Content of phenolic compounds vs. variety, part of apple and cultivation model, extraction of phenolic compounds, biological properties”, Plant Physiol. Biochem. Vol. 84, pp. 169–188, 2014.