Influence of Maturity Stage on Polyphenolic Content and Antioxidant Activity of Fig (Ficus carica L.) Fruit in Native Albanian Varieties

Abstract

Fig fruits, are an important horticultural crop and traditionally grown in Albania. Recently have attracted the attention of many researchers, fruit cultivators, processors, and consumers. This study determined the content of polyphenolic compounds, antioxidant activity and some physico-chemical parameters of black and white varieties of Shëngjinas and Kraps autochthonous fig (Ficus carica L.) fruits, which were collected in Tirana, Albania. The influence of maturity stage on physico-chemical parameters such as dry matter, total soluble solids, titratable acidity, ash, vitamin C, total polyphenols content, flavonoids, anthocyanins, and antioxidant activity were investigated at three maturity stages during the May–June harvesting period. For determination of physico-chemical parameters, the official methods were used, whereas for determination of total phenolic content, the Folin–Ciocalteu method was used. For total flavonoid content, the aluminum chloride colorimetric method was used. For total anthocyanin content, the pH difference method for used, and for antioxidant activity, the ABTS (2,2′-azinobis (3-ethylbenzthiazoline-6-acid) assay was used. In this study, black varieties resulted in 86.92% higher content of polyphenols, and a decrease was noted during fruit development up to 59.16% in the third maturity stage; total flavonoid content varied around 12.02–65.08 mg catechin equivalent/100 g, and antioxidant activity ranged 119.09–181.65 mg ascorbic acid/100 g, whereas anthocyanins were found in black varieties ranging 4.23–48.98 mg cyanidin-3-glucozide/100 g. Black varieties had higher polyphenol compounds and antioxidant activity, whereas Shëngjinas variety resulted in the highest values. During fruit development decreases were seen for polyphenol compounds and antioxidant activity, respectively in the second and third stage of maturation 1.91-fold and 2.45-fold, compared to the first one. The selected fig varieties may provide a good source of phytochemicals and nutrients, and the generated data may serve as a guide for its consumption in fresh state, or to be further processed.