Lime peel ethanolic extract: stability, safety, and sensory evaluation for sustainable valorization

Lime peel, a by-product of the lime (Citrus aurantifolia) processing industry, is rich in bioactive compounds, including flavonoids and limonoids. However, its application as a functional ingredient remains limited due to insufficient safety, stability, and sensory data. Here, we developed a green extraction method at an industrial scale, employing solvent recycling to produce an eco-friendly lime peel extract, and evaluated its short-term stability under various storage conditions. Acute and sub-chronic oral toxicity studies of the extract were performed in Wistar rats (Mlac: WR) in accordance with OECD guidelines No 423 and 408, respectively. A sensory test was conducted in healthy human volunteers to identify the maximum sensory acceptable level of the extract in a beverage. Results showed that the extract powder has intra-batch and inter-batch variability for hesperidin and limonin of '10% and 20%, respectively. The compounds remained stable over 14 days across storage at room temperature (25 °C), 4 °C, and −20 °C. For the acute oral toxicity test, no mortality or treatment-related signs of toxicity were observed, and the extract was categorized as low toxicity (LD₅₀ ' 5000 mg/kg). For the 90-day oral toxicity test, the no observed adverse effect level (NOAEL) is 1500 mg/kg body weight/day, with an estimated acceptable daily intake of 90 mg/day. Up to 1% of lime peel extract in beverages was accepted by consumers. Taken together, the lime peel extract is a novel, safe, and sensory-acceptable ingredient with potential to support sustainable waste valorization, warranting further studies.