Evaluation of the total phenolic content, sugar, organic acid, volatile compounds and antioxidant capacities of fig (Ficus carica L.) genotypes selected from the Mediterranean region of Türkiye

Abstract

Nowadays, the interest in research to determine the healthy compounds in fig fruits has increased, as many of them have been found to be beneficial to human health. This study aimed to determine the sugars, organic acids, total phenolic content, antioxidant capacity and volatile compounds in the fruits of 19 fig (Ficus carica L.) genotypes sampled from the Kahramanmaras province in Türkiye in 2018 and 2019. In the fruit of the fig genotypes, the total phenolic content was determined by the Folin-Ciocalteu method, the total antioxidant capacity was determined by the DPPH (2,2-diphenyl-1-picrylhidrazil) method, the sugars, organic acids and volatile aroma compounds were determined chromatographically (HPLC/RID detector), (HPLC/UV detector) and headspace gas chromatography-mass spectrophotometry (HS-GC/MS), respectively. The results showed that most of the biochemical contents and antioxidant capacities of the genotypes significantly differed from each other (P< 0.05). The total phenolic content and antioxidant properties of the fruits ranged from 50.29 to 580.59 mg gallic acid equivalent per 100 g fresh weight base (and 15.98 to 36.77% DPPH, respectively. Regarding the sugar content of the fig genotypes, the main sugar is fructose ranging from 3.35 to 7.37 g per 100 g. The highest fructose content of 7.37 g per 100 g was found in the genotype KMF12. A total of 58 volatile compounds were detected in the fruits of the 19 fig genotypes, including 18 aldehydes, 3 ketones, 6 esters, 2 terpenes, 17 alcohols, 1 acid and 11 other compounds. According to the obtained results, aldehydes, esters and ketones were found to be the major volatile compounds in the fig fruits. The genotypes with the highest values of the phytochemical and antioxidant properties among the genotypes were selected as candidates as a source of variation for breeders who want to develop new commercial varieties beneficial to human health.