Development of Fortified Citrus Olive Oils: From Their Production to Their Nutraceutical Properties on the Cardiovascular System

Abstract

Recently the use of food by-products as natural sources of biologically active substances has been extensively investigated especially for the development of functional foods fortified with natural antioxidants. Due to their content of bioactive compounds, such as carotenoids, flavonoids and limonoids, citrus peels could be suitable to formulate enriched olive oils able to boost healthy nutrition. The aim of this study was: (i) to determine the compositional and sensory profiles of citrus olive oil; and (ii) to evaluate its nutraceutical properties in rats with high fat diet-induced metabolic syndrome and oxidative stress. The results obtained show the potential of using citrus peels as a source of bioactive compounds to improve the sensory profile as well as the phytochemical composition of olive oil. We demonstrated that the production system of Citrus x aurantium olive oil and Citrus limon olive oil improves its organoleptic properties without altering its beneficial effects, which, like control extra virgin olive oil, showed protective effects relating to glucose and serum lipid levels, metabolic activity of adipocytes, myocardial tissue functionality, oxidative stress markers and endothelial function at blood vessel level.

By-Products from Winemaking and Olive Mill Value Chains for the Enrichment of Refined Olive Oil: Technological Challenges and Nutraceutical Features

“…Total phenols were extracted from the oil as previously described [ 36 ]; the extracts were stored under inert atmosphere (N2 100%) at −20 °C until use. Total phenols concentration was measured by Folin-Ciocalteau colorimetric assay slightly modified: briefly, the extract (1 mL), Folin−Ciocalteu reagent (1 mL), and 7.5% sodium carbonate (9 mL) and deionized water (14 mL), were added to a 25 mL glass flask, mixed, and, after 120 min of incubation at room temperature, absorbance of the samples was measured at 765 nm against a blank.…”

“…The first group was treated with a standard diet (STD, ENVIGO); the others were fed with a high fat diet (HFD, SAFE). In particular, the second group did not receive supplementations (HFD), the third group was treated with extra-virgin olive oil (HFD + EVOO) 5.5% kg/kg (HFD + EVOO, as reference group) mixed in powder feed [ 36 , 40 ]. The fourth group was treated with ROO 2% kg/kg mixed in powder feed.…”

“…Hearts deriving from animals 21 days-treated were cut into small 2–3 mm 3 pieces in ice cold isolation buffer (composition: Sucrose 250 mM, Tris 5 mM, EGTA 1 mM; pH 7.4) and processed as reported in Flori et al [ 36 ]. Briefly, hearts were homogenized by Ultra-Turrax (model: IKA, T-18 Basic) and cardiac mitochondria were isolated through differential centrifugations.…”

“…Western blot was performed on tissue samples as described previously [ 36 ]. Briefly, aortas were homogenized by Tissue Lyser II (#85300 Qiagen, Germantown, MD, USA), sonicated, and centrifuged.…”

“…Briefly, aortas were homogenized by Tissue Lyser II (#85300 Qiagen, Germantown, MD, USA), sonicated, and centrifuged. Electrophoresis (50 μg of protein/sample) was carried out as described [ 36 ]. All experiments were performed at least three times.…”