Fig (Ficus carica) Liquid Co-Products as New Potential Functional Ingredient: Physico-Chemical and In Vitro Antioxidant Properties

The aims of this study were to determine (i) the physico-chemical characteristics, (ii) the phenolic, flavonoid and anthocyanins profile, (iii) the organic acids and sugar content, and (iv) the antioxidant properties of the liquid co-product generated by the figs (FLC) processing industry in order to set standards for its applications as a potential ingredient of food products. The liquid co-products obtained from the peel and pulp of two fig varieties (colar and cuello de dama) were used. The polyphenolic profile and the organic acids and sugar were determined by HPLC. For the antioxidant activity, four different test systems were used (DPPH, FRAP, TBARS and FIC). The total phenolic, total flavonoid and total anthocyanin contents were also determined. The FLC from peel presented higher total phenolic, flavonoid and anthocyanin contents than FLC from pulp. The FLC obtained from peel and pulp had a high content of sugars, mainly glucose and fructose. As regards antioxidant activity, at all concentrations and with all methods, FLC obtained from peel presented higher antioxidant activity than the pulp FLC. FLC obtained from the peel and pulp could be an alternative for use as a natural preservative in food matrices due to its broad antioxidant activity.