In Vitro Bioaccessibility of Bioactive Compounds from Citrus Pomaces and Orange Pomace Biscuits

Abstract

The present investigation aimed to provide novel information on the chemical composition and in vitro bioaccessibility of bioactive compounds from raw citrus pomaces (mandarin varieties Clemenule and Ortanique and orange varieties Navel and Valencia). The effects of the baking process on their bioaccessibility was also assessed. Samples of pomaces and biscuits containing them as an ingredient were digested, mimicking the human enzymatic oral gastrointestinal digestion process, and the composition of the digests were analyzed. UHPLC-MS/MS results of the citrus pomaces flavonoid composition showed nobiletin, hesperidin/neohesperidin, tangeretin, heptamethoxyflavone, tetramethylscutellarein, and naringin/narirutin. The analysis of the digests indicated the bioaccessibility of compounds possessing antioxidant [6.6–11.0 mg GAE/g digest, 65.5–97.1 µmol Trolox Equivalents (TE)/g digest, and 135.5–214.8 µmol TE/g digest for total phenol content (TPC), ABTS, and ORAC-FL methods, respectively; significant reduction (p < 0.05) in Reactive Oxygen Species (ROS) formation under tert-butyl hydroperoxide (1 mM)-induced conditions in IEC-6 and CCD-18Co cells when pre-treated with concentrations 5–25 µg/mL of the digests], anti-inflammatory [significant reduction (p < 0.05) in nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW264.7 macrophages], and antidiabetic (IC50 3.97–11.42 mg/mL and 58.04–105.68 mg/mL for α-glucosidase and α-amylase inhibition capacities) properties in the citrus pomaces under study. In addition, orange pomace biscuits with the nutrition claims “no-added sugars” and “source of fiber”, as well as those with good sensory quality (6.9–6.7, scale 1–9) and potential health promoting properties, were obtained. In conclusion, the results supported the feasibility of citrus pomace as a natural sustainable source of health-promoting compounds such as flavonoids. Unfractionated orange pomace may be employed as a functional food ingredient for reducing the risk of pathophysiological processes linked to oxidative stress, inflammation, and carbohydrate metabolism, such as diabetes, among others.

Tangeretin promotes lifespan associated with insulin/insulin‐like growth factor‐1 signaling pathway and heat resistance in Caenorhabditis elegans

“…Wang et al reported that orange extracts with high amount of hesperidin prolonged the mean lifespan of worms by 26.4%, suggesting that hesperidin may be the main contributor in lifespan extension of the extracts 15 . Nobiletin, a main flavonoid in mandarin pomaces, 41 enhanced the mean lifespan by 21% and also exhibits beneficial effects on aging‐related functional declines. And the 50 μM of naringin can remarkably prolong the mean lifespan of C. elegans by 17.30% 42 .…”

Tannat Grape Skin: A Feasible Ingredient for the Formulation of Snacks with Potential for Reducing the Risk of Diabetes

“…To evaluate the amelioration of intracellular formation of Reactive Oxygen Species (ROS) by TGS yogurt digest three cell lines were employed: IEC-6 (normal rat small intestine epithelial cells), CCD-18Co (normal human colon fibroblast cells) and RAW264.7 (mouse macrophages) cells. The assays were carried out as described by Fernández-Fernández et al [ 25 ]. The tests were carried out by seeding 20,000 IEC-6, 10,000 CCD-18Co and 80,000 RAW264.7 cells/well in sterile 96-well plates and incubating for 24 h reaching cell confluence.…”

Upgrading the physiochemical and sensory quality of yogurt by incorporating polyphenol-enriched citrus pomaces with antioxidant, antimicrobial, and antitumor activities

“…According to Fernández et al ( 40 ), the phenolic content of mandarin pomace ranged from 6.6 to 11.0 mg GAE/g, whereas grapefruit, orange, and lemon peels had high phenolic content, i.e., 77.3, 49.8, and 35.6 mg of GAE/g, respectively, with a moderate antioxidant activity ranging from 73 to 75% ( 41 ).…”

“…Montenegro-Landvar et al ( 45 ) that aqueous extract of orange waste might be a substantial source of 4-hydroxybenzoic acid and hesperidin. The flavonoid contents in the citrus pomace's methanolic extract showed nobiletin, hesperidin/neo-hesperidin, tangerine, heptamethoxyflavone, tetramethyl scutellarin, and naringin/narirutin were detected by UHPLC-MS/MS ( 40 ).…”