Ultrasensitive and selective determination of naringin using eggplant peel- derived nitrogen doped-carbon dots after extraction with Amberlite IRA-400: Evaluation the bitterness of grapefruit juice

This work presents a novel approach for the accurate determination of naringin (NAR) in grapefruit juice. In the proposed method, N-doped carbon dots were employed, which were synthesized via hydrothermal synthesis using eggplant peel food waste as a green precursor. Detection of NAR relied on measuring the probe's emission response, which exhibited a decrease at 430 nm in the presence of NAR. The bitterness caused by NAR in grapefruit juice significantly impacts customer acceptability and can lead to economic losses if its levels exceed a certain threshold. It was found that the fluorescence quenching method showed excellent linearity in the concentration range of 0.0–2500.0 ng mL−1 (R2 = 0.9990), with a remarkable limit of detection(S/N = 3) of 16.37 ng mL−1. Furthermore, selective extraction of NAR from grapefruit juice samples was achieved using Amberlite IRA-400 ion exchange resin. The adsorption parameters were carefully selected, and adsorption isotherm models were evaluated to determine the adsorption mechanism. The efficacy of the developed method was demonstrated by its successful application in determining NAR levels in grapefruit juice at various stages of maturity. This study demonstrates the potential of the proposed method as a reliable and efficient tool for accurately determining NAR in grapefruit juice.