Simultaneous extraction and separation of bioactive compounds from apple pomace using pressurized liquids coupled on-line with solid-phase extraction.

The objective of this work was the development of an on-line extraction/fractionation method based on the coupling of pressurized liquid extraction and solid-phase extraction for the separation of phenolic compounds from apple pomace. Several variables of the process were evaluated, including the amount of water of the first stage (0-120 mL), temperature (60-80 °C), solid-phase extraction adsorbent (Sepra, Isolute, Strata X and Oasis) and activation/elution solvent (methanol and ethanol). The best results were observed with the adsorbent Sepra. The temperature had a small effect on recovery, but significant differences were observed for phlorizin and a quercetin derivative. Results indicate that ethanol can be used to replace methanol as an activation, extraction/elution solvent. While using mostly green solvents (water, ethanol, and a small amount of methanol that could be reused), the developed method produced higher or similar yields of acids (2.85 ± 0.19 mg/g) and flavonoids (0.97 ± 0.11 mg/g) than conventional methods.

Beet Stalks and Leaves (Beta vulgaris L.) Protect Against High-Fat Diet-Induced Oxidative Damage in the Liver in Mice.

Some flavonoids identified in beet stalks can help the antioxidant endogenous defenses during a chronic inflammation process. The current study investigates the effect of polyphenols present in beet stalks and leaves on liver oxidative damage in mice fed a high-fat diet (HF). The control (CT) or HF diet groups were supplemented with dehydrated beet stalks and leaves (SL) or beet stalk and leaf ethanolic extract (EX). In terms of Vitexin-rhaminoside equivalents (VRE), EX groups received ~5.91 mg of VRE·100 g−1 diet, while the SL groups received ~3.07 mg VRE·100 g−1 diet. After 8 weeks, we evaluated fasting blood glucose; cholesterol, hepatic Malondialdehyde (MDA) levels and hepatic Glutathione (GSH), Glutathione peroxidase (GPx), Glutathione reductase (GR) and Superoxide dismutase (SOD) activity. Dehydrated beet stalks and leaves (HFSL) attenuated the deleterious effects of a HF diet on lipid metabolism, reduced fasting blood glucose levels, ameliorated cholesterol levels and reduced GPx and GR activities (p < 0.05) compared to the HF group. However; the addition of ethanolic extract from beet stalks and leaves was unable (p > 0.05) to prevent the liver damage caused by HF diet in mice. The presence of flavonoids, such as Vitexin derivatives in beet stalks and leaves can help the liver damage induced by HF diet.