The incorporation of a pomegranate peel extract in the formulation of uncured dry sausages protects lipids and proteins from oxidation during in vitro gastrointestinal digestion

Abstract

The effect of nitrite (0 and 150 mg/kg NaNO2) and a pomegranate peel extract (PPE) (0, 1, and 2 mL/100 g) in the formulation of dry sausages on lipid -conjugated dienes (CDEs), lipid hydroperoxides (LOOHs), malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), saturated aldehydes (SAld), - and protein oxidation -carbonyls and free thiols- before and during simulated gastrointestinal digestion were investigated. The initial oxidation status of the sausages was greatly affected by nitrite and PPE and influenced the evolution of oxidative phenomena during simulated digestion. The removal of nitrite from the sausage formulation had a negative impact on the oxidative stability of both dry sausages and digests, leading to increased levels (P < .05) of CDEs, LOOHs, MDA, 4-HNE, and SAld. Additionally, the elimination of nitrite also resulted in an increase (P < .05) in the carbonyl content in both the sausages and their digests. The PPE added to sausages counteracted the deleterious effect of nitrite removal and reduced (P < .05) lipid and protein oxidation markers in dry sausages and digests. The protective effect of PPE against oxidation was dose-dependent. Pomegranate peel extract may represent a successful strategy to prevent or slow down lipid oxidation and protein oxidation in dry sausages before and during in vitro digestion.