The total phenolic content, anthocyanins, phenolic acids, antioxidant capacity and α-amylase inhibitory activity of black (Aydin Siyahi), purple (Kadife Kemer) and white (Trabzon Kadife) eggplants grown in Turkey were subjected to a comparative investigation. The black cultivar exhibited the highest total phenolic (17,193 and 6552 mg gallic acid equivalent/kg fw), flavonoid (3019 and 1160 quercetin equivalent/kg fw) and anthocyanin (1686 and 6167 g delphinidin-3-O-glucoside equivalent/kg fw) contents in crude extracts of the peel and pulp. The majority of the caffeic acid was identified in the ester (2830 mg/kg fw) and ester-bound (2594 mg/kg fw) forms in the peel of 'Kadife Kemer' and in the glycoside form (611.9 mg/kg fw) in 'Aydin Siyahi', as well as in the pulp of these two eggplants. 'Kadife Kemer' (purple eggplant) contained the majority of the chlorogenic acid in free form (27.55 mg/kg fw), compared to 'Aydin Siyahi' in the ester (7.82 mg/kg fw), glycoside (294.1 mg/kg dw) and ester-bound (2.41 mg/kg fw) forms. The eggplant cultivars (peel and pulp, mg/kg fw) exhibited a relatively high delphinidin-3-O-rutinoside concentration in the peel of 'Aydin Siyahi' (avg. 1162), followed by 'Kadife Kemer' (avg. 336.6), and 'Trabzon Kadife' (avg. 215.1). The crude phenolic extracts of the eggplants exhibited the highest antioxidant capacity values (peel and pulp, µmoL Trolox equivalent/kg fw) of 2,2-diphenyl-1-picrylhydrazyl (DPPH, 8156 and 2335) and oxygen radical absorbance capacity (ORAC, 37,887 and 17,648). The overall results indicate that black and purple eggplants are the cultivars with greater potential benefits in terms of their phenolics and antioxidant values than the white eggplant.

Department of Biology Faculty of Science Karadeniz Technical University Trabzon 61080 Turkey

Department of Experimental Biology Palacky University Olomouc Slechtitelu 27 783 71 Olomouc Czech Republic

Department of Herbal Medicine Resource Dogye Campus Kangwon National University Hwangjori 3 Dogye up Samcheok 25949 Korea

Institute of Food Science and Human Nutrition Gottfried Wilhelm Leibniz University Hannover Am Kleinen Felde 30 30167 Hannover Germany

Laboratory of Growth Regulators Faculty of Science Palacky University and Institute of Experimental Botany AS CR Slechtitelu 27 783 71 Olomouc Czech Republic

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Salerno L., Modica M.N., Pittalà V., Romeo G., Siracusa M.A., Di Giacomo C., Sorrenti V., Acquaviva R. Antioxidant activity and phenolic content of microwave-assisted Solanum melongena Extracts. Sci. World J. 2014;11:719486. PubMed PMC

Cory H., Passarelli S., Szeto J., Tamez M., Mattei J. The Role of polyphenols in human health and food systems: A mini-review. Front. Nutr. 2018;5:87. doi: 10.3389/fnut.2018.00087. PubMed DOI PMC

Niño-Medina G., Urías-Orona V., Muy-Rangel M.D., Heredia J.B. Structure and content of phenolics in eggplant (Solanum melongena)—A review. S. Afr. J. Bot. 2017;111:161–169. doi: 10.1016/j.sajb.2017.03.016. DOI

Stommel J.R., Whitaker B.D. Phenolic acid content and composition of eggplant fruit in a germplasm core subset. J. Am. Soc. Hortic. Sci. 2003;128:704–710. doi: 10.21273/JASHS.128.5.0704. DOI

Singh A.P., Luthria D., Wilson T., Vorsa N., Singh V., Banuelos G.S., Pasakdee S. Polyphenols content and antioxidant capacity of eggplant. Food Chem. 2009;114:955–961. doi: 10.1016/j.foodchem.2008.10.048. DOI

Zaro M.J., Keunchkarian S., Chaves A.R., Vicente A.R., Concellón A. Changes in bioactive compounds and response to postharvest storage conditions in purple eggplants as affected by fruit developmental stage. Postharvest Biol. Technol. 2014;96:110–117. doi: 10.1016/j.postharvbio.2014.05.012. DOI

Zaro M.J., Ortiz L.C., Keunchkarian S., Chaves A.R., Vicente A.R., Cocellon A. Chlorogenic acid retention in white and purple eggplant after processing and cooking. LWT Food Sci. Technol. 2015;64:802–808. doi: 10.1016/j.lwt.2015.06.061. DOI

Boyacı H., Topçu V. Development of eggplant hybrid cultivar ‘BATEM FILIZI’ and determination of yield performance. Derim. 2014;31:11–22. doi: 10.16882/derim.2014.94310. DOI

Güvenç İ. Türkiye ve Avrupa Birliği ülkelerinin sebze üretimi ve kendine yeterlilik bakımından karşılaştırılması. Yyü. Tar. Bil. Derg. 2018;28:530–535. doi: 10.29133/yyutbd.455568. DOI

Sadilova E., Stintzing F.C., Carle R. Anthocyanins, colour and antioxidant properties of eggplant (Solanum melongena L.) and violet pepper (Capsicum annuum L.) peel extracts. Z. Naturforsch. C. 2006;7–8:527–535. doi: 10.1515/znc-2006-7-810. PubMed DOI

Hanson P.M., Yang R.Y., Tsou S.C.S., Ledesma D., Engle L., Lee T.C. Diversity on eggplant (Solanum melongena) for superoxide scavenging activity, total phenolics, and ascorbic acid. J. Food Comp. Anal. 2006;19:594–600. doi: 10.1016/j.jfca.2006.03.001. DOI

Raigón M.D., Prohens J., Muñoz-Falcón J.E., Nuez F. Comparison of eggplant landraces and commercial varieties for fruit content of phenolics, minerals, dry matter and protein. J. Food Comp. Anal. 2008;21:370–376. doi: 10.1016/j.jfca.2008.03.006. DOI

Colak N., Primetta A.K., Riihinen K.R., Jaakola L., Grúz J., Strnad M., Torun H., Ayaz F.A. Phenolic compounds and antioxidant capacity in different-colored and non-pigmented berries of bilberry (Vaccinium myrtillus L.) Food Biosci. 2017;20:67–78. doi: 10.1016/j.fbio.2017.06.004. DOI

Hano C., Tungmunnithum D. Plant polyphenols, more than just simple natural antioxidants: Oxidative stress, aging and age-related diseases. Medicines. 2020;7:26. doi: 10.3390/medicines7050026. PubMed DOI PMC

Panche A.N., Diwan A.D., Chandra S.R. Flavonoids: An overview. J. Nutr. Sci. 2016;5:e47. doi: 10.1017/jns.2016.41. PubMed DOI PMC

Dias M.C., Pinto D.C.G.A., Silva A.M.S. Plant flavonoids: Chemical characteristics and biological activity. Molecules. 2021;26:5377. doi: 10.3390/molecules26175377. PubMed DOI PMC

Plazas M., Andújar I., Vilanova S., Hurtado M., Gramazio P., Herráiz F.J., Prohens J. Breeding for chlorogenic acid content in eggplant: Interest and prospects. Not. Bot. Horti Agrobot. Cluj Napoca. 2013;41:26–35. doi: 10.15835/nbha4119036. DOI

Liu Y., Tikunov Y., Schouten R.E., Marcelis L.F.M., Visser R.G.F., Bovy A. Anthocyanin Biosynthesis and Degradation Mechanisms in Solanaceous Vegetables: A Review. Front. Chem. 2018;6:52. doi: 10.3389/fchem.2018.00052. PubMed DOI PMC

Luthria D.L. A simplified UV spectral scan method for the estimation of phenolic acids and antioxidant capacity in eggplant pulp extracts. J. Funct. Foods. 2012;4:238–242. doi: 10.1016/j.jff.2011.11.002. DOI

Kwon Y.I., Apostolidis E., Shetty K. In vitro studies of eggplant (Solanum melongena) phenolics as inhibitors of key enzymes relevant for type 2 diabetes and hypertension. Bioresour. Technol. 2008;99:2981–2988. doi: 10.1016/j.biortech.2007.06.035. PubMed DOI

Li W., Yuan G., Pan Y., Wang C., Chen H. Network pharmacology studies on the bioactive compounds and action mechanisms of natural products for the treatment of diabetes mellitus: A Review. Front. Pharmacol. 2017;8:74. doi: 10.3389/fphar.2017.00074. PubMed DOI PMC

Singh D., Chaudhary G., Yadav D.K. Genetic diversity of Indian isolates of Ralstonia solanacearum causing bacterial wilt of eggplant (Solanum melongena) Ind. J. Agric. Sci. 2017;87:1466–1475.

Sharma M., Kaushik P. Biochemical Composition of Eggplant Fruits: A Review. Appl. Sci. 2021;11:7078. doi: 10.3390/app11157078. DOI

Sun L., Warren F.J., Netzel G., Gidley M.J. 3 or 3′-Galloyl substitution plays an important role in association of catechins and theaflavins with porcine pancreatic α-amylase: The kinetics of inhibition of α-amylase by tea polyphenols. J. Funct. Foods. 2016;26:144–156. doi: 10.1016/j.jff.2016.07.012. DOI

Sun L., Wang Y., Miao M. Inhibition of α-amylase by polyphenolic compounds: Substrate digestion, binding interactions and nutritional intervention. Trends Food Sci. Technol. 2020;104:190–207. doi: 10.1016/j.tifs.2020.08.003. DOI

Cao J., Zhang Y., Han L., Zhang S., Duan X., Sun L., Wang M. Number of galloyl moieties and molecular flexibility are both important in alpha-amylase inhibition by galloyl-based polyphenols. Food Funct. 2020;11:3838–3850. doi: 10.1039/C9FO02735A. PubMed DOI

Torun H., Kolcuoğlu Y., Ayaz F.A., Çolak A., Glew R.H. Characterization of polyphenol oxidase during three ripening stages of an eggplant (Solanum melongena L.) fruit: A local type in northeast Anatolia. Turk. J. Biochem. 2015;40:44–50.

Akanitapichat P., Phraibung K., Nuchklang K., Prompitakkul S. Antioxidant and hepatoprotective activities of five eggplant varieties. Food Chem. Toxicol. 2010;48:3017–3021. doi: 10.1016/j.fct.2010.07.045. PubMed DOI

Bor J.Y., Chen H.Y., Yen G.H. Evaluation of antioxidant activity and inhibitory effect on nitric oxide production of some common vegetables. J. Agric. Food Chem. 2006;54:1680–1686. doi: 10.1021/jf0527448. PubMed DOI

Boulekbache-Makhlouf L., Medouni L., Medouni-Adrar S., Arkoub L., Madani K. Effect of solvents extraction on phenolic content and antioxidant activity of the by product of eggplant. Ind. Crops Prod. 2013;49:668–674. doi: 10.1016/j.indcrop.2013.06.009. DOI

Valanciene E., Jonuskiene I., Syrpas M., Augustiniene E., Matulis P., Simonavicius A., Malys N. Advances and prospects of phenolic acids production, biorefinery and analysis. Biomolecules. 2020;10:874. doi: 10.3390/biom10060874. PubMed DOI PMC

Gürbüz N., Uluişik S., Frary A., Frary A., Doğanlar S. Health benefits and bioactive compounds of eggplant. Food Chem. 2018;268:602–610. doi: 10.1016/j.foodchem.2018.06.093. PubMed DOI

Tanchev S.S., Ruskov P.J., Timberlake C.F. The anthocyanins of Bulgarian aubergine (Solanum melongena) Phytochemistry. 1970;9:1681–1682. doi: 10.1016/S0031-9422(00)85298-X. DOI

Azuma K., Ohyama A., Ippoushi K., Ichiyanagi T., Tekeuchi A., Saito T., Fukuoka H. Structures and antioxidant activity of anthocyanins in many accessions of eggplant and its related species. J. Agric. Food Chem. 2008;56:10154–10159. doi: 10.1021/jf801322m. PubMed DOI

Wu X., Prior R.L. Identification and characterization of anthocyanins by high performance liquid chromatography-electrospray ionization-tandem mass spectrometry in common foods in the United States: Vegetables, nuts, and grains. J. Agric. Food Chem. 2005;53:3101–3113. doi: 10.1021/jf0478861. PubMed DOI

Calumpang C.L.F., Saigo T., Watanabe M., Tohge T. Cross-Species Comparison of Fruit-Metabolomics to Elucidate Metabolic Regulation of Fruit Polyphenolics Among Solanaceous Crops. Metabolites. 2020;10:209. doi: 10.3390/metabo10050209. PubMed DOI PMC

Toppino L., Barchi L., Lo Scalzo R., Palazzolo E., Francese G., Fibiani M., D’Alessandro A., Papa V., Laudicina V.A., Sabatino L., et al. Mapping quantitative trait loci affecting biochemical and morphological fruit properties in eggplant (Solanum melongena L.) Front. Plant Sci. 2016;7:256. doi: 10.3389/fpls.2016.00256. PubMed DOI PMC

Zhang Y., Hu Z., Chu G., Huang C., Tian S., Zhao Z., Chen G. Anthocyanin accumulation and molecular analysis of anthocyanin biosynthesis-associated genes in eggplant (Solanum melongena L.) J. Agric. Food Chem. 2014;62:2906–2912. doi: 10.1021/jf404574c. PubMed DOI

Stommel J.R., Dumm J.M. Coordinated regulation of biosynthetic and regulatory genes coincides with Anthocyanin Accumulation in developing eggplant fruit. J. Am. Soc. Hortic. Sci. 2015;140:129–135. doi: 10.21273/JASHS.140.2.129. DOI

Gisbert C., Dumm J.M., Prohens J., Vilanova S., Stommel J.R. A spontaneous eggplant (Solanum melongena L.) color mutant conditions anthocyanin-free fruit pigmentation. Hortscience. 2016;51:793–798. doi: 10.21273/HORTSCI.51.7.793. DOI

Jiang M., Liu Y., Ren L., Lian H.L., Chen H.Y. Molecular cloning and characterization of anthocyanin biosynthesis genes in eggplant (Solanum melongena L.) Acta Physiol. Plant. 2016;38:163. doi: 10.1007/s11738-016-2172-0. DOI

Woodward G., Kroon P., Cassidy A., Kay C. Anthocyanin stability and recovery: Implications for the analysis of clinical and experimental samples. J. Agric. Food Chem. 2009;57:5271–5278. doi: 10.1021/jf900602b. PubMed DOI

Zhang Y., Butelli E., Martin C. Engineering anthocyanin biosynthesis in plants. Curr. Opin. Plant Biol. 2014;19:81–90. doi: 10.1016/j.pbi.2014.05.011. PubMed DOI

Lachman J., Hamouz K. Red and purple coloured potatoes as a significant antioxidant source in human nutrition—A review. Plant Soil Environ. 2005;51:477–482. doi: 10.17221/3620-PSE. DOI

Miao M., Jiang H., Jiang B., Li Y., Cui S.W., Zhang T. Structure elucidation of catechins for modulation of starch digestion. LWT Food Sci. Technol. 2014;57:188–193. doi: 10.1016/j.lwt.2014.01.005. DOI

Liu Y., Chen P., Zhou M., Wang T., Fang S., Shang X., Fu X. Geographic variation in the chemical composition and antioxidant properties of phenolic compounds from Cyclocarya paliurus (Batal) Iljinskaja Leaves. Molecules. 2018;23:2440. doi: 10.3390/molecules23102440. PubMed DOI PMC

Abdi H., Williams L.J. Principal component analysis. WIREs Comp. Stat. 2010;2:433–459. doi: 10.1002/wics.101. DOI

Hossain M., Li J., Sikdar A., Hasanuzzaman M., Uzizerimana F., Muhammad I., Yuan Y., Zhang C., Feng B. Exogenous melatonin modulates the physiological and biochemical mechanisms of drought tolerance in tartary buckwheat (Fagopyrum tataricum (L.) Gaertn) Molecules. 2020;25:2828. doi: 10.3390/molecules25122828. PubMed DOI PMC

Colak N., Kurt-Celebi A., Fauzan R., Torun H., Ayaz F.A. The protective effect of exogenous salicylic and gallic acids ameliorates the adverse effects of ionizing radiation stress in wheat seedlings by modulating the antioxidant defence system. Plant Physiol. Biochem. 2021;168:526–545. doi: 10.1016/j.plaphy.2021.10.020. PubMed DOI

Torun H., Novák O., Mikulík J., Strnad M., Ayaz F.A. The Effects of exogenous salicylic acid on endogenous phytohormone status in Hordeum vulgare L. under salt stress. Plants. 2022;11:618. doi: 10.3390/plants11050618. PubMed DOI PMC

Rodriguez-Saona L.E., Wrolstad R.E. Extraction, Isolation, and Purification of Anthocyanins. Curr. Protoc. Food Anal. Chem. 2001;1:F1-1. doi: 10.1002/0471142913.faf0101s00. DOI

Slinkard K., Singleton V.L. Total phenol analysis: Automation and comparison with manual methods. Am. J. Enol. Vitic. 1977;28:49–55.

Huang D.J., Lin C.D., Chen H.J., Lin Y.H. Antioxidant and antiproliferative activities of sweet potato [Ipomoea batatas (L.) Lam ‘Tainong 57′] constituents. Bot. Bull. Acad. Sinica. 2004;45:179–186.

Giusti M., Rodríguez-Saona L.E., Wrolstad R.E. Molar absorptivity and color characteristics of acylated and non-acylated pelargonidin-based anthocyanins. J. Agric. Food Chem. 1999;47:4631–4637. doi: 10.1021/jf981271k. PubMed DOI

Blois M.S. Antioxidant determinations by the use of stable free radical. Nature. 1958;181:1199–1200. doi: 10.1038/1811199a0. DOI

Ou B., Hampsch-Woodill M., Prior R.L. Development and validation of an improved oxygen radical absorbance capacity assay using fluorescein as the fluorescent probe. J. Agric. Food Chem. 2001;49:4619–4626. doi: 10.1021/jf010586o. PubMed DOI

Ayaz F.A., Hayirlioglu-Ayaz S., Gruz J., Novak O., Strnad M. Separation, characterization, and quantitation of phenolic acids in a little-known blueberry (Vaccinium arctostaphylos L.) fruit by HPLC-MS. J. Agric. Food Chem. 2005;53:8116–8122. doi: 10.1021/jf058057y. PubMed DOI

Gruz J., Novák O., Strnad M. Rapid analysis of phenolic acids in beverages by UPLC–MS/MS. Food Chem. 2008;111:789–794. doi: 10.1016/j.foodchem.2008.05.014. DOI

Lee J.H., Lee H.-J., Choung M.-G. Anthocyanin compositions and biological activities from the red petals of Korean edible rose (Rosa hybrida cv. Noblered) Food Chem. 2011;129:272–278. doi: 10.1016/j.foodchem.2011.04.040. PubMed DOI

Phan M.A.T., Wang J., Tang J., Lee Y.L., Ng K. Evaluation of α-glucosidase inhibition potential of some flavonoids from Epimedium brevicornum. LWT Food Sci. Technol. 2013;53:492–498. doi: 10.1016/j.lwt.2013.04.002. DOI

Esatbeyoglu T., Rodríguez-Werner M., Schlösser A., Winterhalter P., Rimbach G. Fractionation, enzyme inhibitory and cellular antioxidant activity of bioactives from purple sweet potato (Ipomoea batatas) Food Chem. 2017;221:447–456. doi: 10.1016/j.foodchem.2016.10.077. PubMed DOI