Effect of peeling, filling medium, and storage on the antioxidant activity and phenolic compounds of canned figs (Ficus carica L.)

Abstract

The fig fruit, which has a short seasonal availability due to its perishable nature, was subjected to a canning process, and the effects of canning on phenolics and antioxidant properties were evaluated. For this purpose, the most popular fig varieties grown in Türkiye, namely Sarilop (yellow coloured) and Bursa Siyahi (dark purple coloured), were canned in different filling mediums such as syrup, water, and fig juice, as peeled or unpeeled. The canned figs were also stored at room temperature for 12 months, and the changes in phenolics and antioxidant properties during storage were determined. The canning process preserved a great part of the phenolics and antioxidant capacity. After canning, the Sarilop figs experienced a minor reduction in their total phenolic content, whereas no significant change was observed in the total phenolic content of the Bursa Siyahi figs. The total antioxidant activity of the figs increased by canning, which was observed more clearly for the unpeeled Bursa Siyahi figs. At the end of the storage, both Sarilop and Bursa Siyahi figs canned with fig juice had higher total phenolics, total antioxidant activity, and individual phenolics than the figs canned with other filling mediums. During the 12-month storage period, the most stable phenolic compounds found in the canned figs were rutin and gallic acid. However, the monomeric anthocyanins of the Bursa Siyahi figs were negatively affected by the storage and canning process.