The Phenolics and Antioxidant Properties of Black and Purple versus White Eggplant Cultivars

Abstract

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.

Ultraviolet-c Radiation Induced Changes on Bioactive Compounds Content, Antioxidant Capacity and Microbial Quality of Minimally Processed Molokhia (Corchorus Olitorius L.) Leaves

“…This was suggested to result from the novo synthesis of Maillard intermediates with antioxidant properties. In similar study, Nesrin, et al [90] found that the crude phenolic extracts of the eggplants fruit parts (peel and pulp) exhibited high antioxidant and scavenging activities which correlated with the cultivars. The black and purple eggplants are the cultivars with greater potential benefits in terms of their phenolics and antioxidant values than the white eggplant.…”

“…Total phenolics, β-carotene, flavonoids and anthocyanins were determined in eggplant fruits as shown in Table (4). Phenolics was reported the most abundant ones, followed by anthocyanins, flavonoids and β-carotene.…”

“…Effect of freezing process on antioxidant activity of eggplant was studied as shown in Table (8) and Figure (4). Freezing has been shown to cause significant (p≤ 0.05) increase of antioxidant activities of eggplant fruits.…”

“…Eggplant (Solanum melongena L. Family: Solanaceae) also known as aubergine, brinjal, melanzane, berenjena or patlıcan is very popular vegetable grown over 1.7 million hectares world-wide [2]. It is an economically important vegetable crop of tropical and subtropical zones of the world including Asia (47,142,210 tons), Africa (1,814,535 tons), Europe (936,642 tons), the Americas (295,387 tons) and Oceania (4342 tons) [3,4]. In 2020, Egypt ranks third in the world in eggplant production with an annual production of approximately 1.34 million metric tons (https://www.tridge.com/intelligences/eggplant/EG).…”

Employ of Anthocyanins in nanocarriers for Nano Delivery: <em>I</em><em>n Vitro</em> and <em>I</em><em>n Vivo</em> Experimental Approaches for Chronic Diseases

“…In vegetables, TAC levels around 150 mg C3G per 100 g fw are found in eggplant, purple sweet potato, and red cabbage. Among anthocyanins, delphinidin 3-O-rutinoside is the predominant one in eggplant [78], while 3-O-sophoroside-5-glucoside derivatives of peonidin and cyanidin are the most important in purple sweet potato [79]. On the other hand, cyanidin-3-diglucoside-5-glucoside, cyanidin-3-(sinapoyl)(sinapoyl)-diglucoside-5-glucoside and cyanidin-3-(ρ-coumaroyl)-diglucoside-5-glucoside are most commonly in red cabbage [80].…”