Bioactive phytochemicals in industrial tomatoes and their processing byproducts

Tomato processing byproducts, together with unprocessed tomatoes were analyzed for several bioactive phytochemicals, like sterols, tocopherols, carotenes, terpenes, total and simple polyphenols. In addition, their radical scavenging capacity and reducing power were assayed. On a dry weight (DW) basis, tomato wastes contained significantly lower amounts of lycopene and increased amounts of β-carotene, tocopherols, sterols and terpenes, while their fatty acid profile was similar to that of unprocessed tomatoes. Tomato byproducts contained similar amount of total polyphenols and exhibited similar DPPH radical scavenging activity and ferric reducing power with tomatoes. Among 18 simple polyphenols determined by GC/MS, hydroxycinnamic acids predominated in whole tomatoes, while flavonoids predominated in tomato wastes with naringenin comprising 87% of flavonoids. As most of the phytochemicals determined exert antioxidant activities, tomato processing byproducts could be successfully utilized as functional ingredient for the formulation of antioxidant rich functional foods.

► Tomato byproducts contain lycopene, β-carotene, tocopherols and phytosterols.
► They also contain polyphenols – mainly flavonoids – and terpenes.
► In addition, they exert radical scavenging and antioxidant potential.
► It is concluded that tomato byproducts can serve as functional food ingredients.