Knowledge Bank

Naringenin and naringin, flavonoids found in citrus fruits, may possess antioxidative, anti-inflammatory, hypolipidemic, and anticancer properties - such as mitigation of cachexia symptoms. Encapsulation can likely improve their solubility, bioavailability, and bitter taste. The usage of extracted naringin from grapefruit for potential health enhancement could decrease cost while meeting food additive regulations. Previous work in our lab has demonstrated high encapsulation efficiencies of naringin standards with β-cyclodextrin (β-CD). It was, therefore, hypothesized that under the same conditions, naringin extracted from grapefruit would also complex efficiently with β-CD. First, food-safe methods to extract naringin from a grapefruit peel powder were compared. High-performance liquid chromatography (HPLC) measured naringin concentrations, and sonication and increased extraction volume improved extraction efficiencies by 57% to 2.47 ± 0.15 g naringin /100 g grapefruit peel powder, consistent with literature results. Second, the complexation efficiencies of β-CD with extracted naringin using kneading and stirring methods were compared. Analysis by nuclear magnetic resonance spectroscopy (H-NMR) was complicated by interference from extracted impurities. One unknown peak was found in the NMR spectra for encapsulations prepared by a kneading method, which suggested a difference for this method. Lastly, model systems with naringin and naringenin were processed by microfluidization to evaluate whether high shear could convert naringin into naringenin for bioavailability improvement; results strongly suggest that it cannot. Future work to clarify encapsulation efficiency is needed, but along with previous studies, this pre-translational work can help lead to future trials in cancer cachexia mitigation, or more generally, health promotion from naringin intake.