Enrichment of tomato sauce and chopped tomatoes with tomato by-products increases antioxidant activity upon in vitro digestion

This study aimed to reutilize a by-product of the tomato-processing industry, tomato pomace. Two types of tomato sauce were developed incorporating tomato pomace by 50% (SWS) or 100% (WTS) and chopped tomatoes using WTS as filling sauce (WCT). The carotenoids, α-tocopherol, and polyphenols content in the products and bioaccessible fractions from in vitro digestion were assessed compared to a conventional sauce (TS) and chopped tomatoes (TCT). The total antioxidant capacity (TAC) before the digestion, in the bioaccessible fractions and the residue of digestion was measured. The innovative products showed a higher content of all carotenoids (mainly lycopene), α-tocopherol, and TAC vs conventional products. Polyphenols were more abundant only in the WCT than TCT. Compared to the conventional products, bioaccessibility of: carotenoids decreased by 48% from SWS and WS, whereas increased by 19% from WCT; α-tocopherol increased by 26% from SWS; total polyphenols decreased by 37% and 56% from SWS and WS, whereas increased by 19% from WCT. TAC of bioaccessible fractions and residues of digestion from innovative products increased by 1.3- to 4-folds. Reutilizing tomato pomace in tomato processing led to products with increased carotenoids, α-tocopherol, and TAC besides enhanced oxidative reducing potential along the gastro-intestinal tract until the colon.