A Green Extraction Method to Achieve the Highest Yield of Limonin and Hesperidin from Lime Peel Powder (Citrus aurantifolia)

What if the secret to a healthier life is hiding in the peel you throw away? Scientists have found a green way to squeeze out the maximum amount of two powerful bioactive compounds from lime peel waste.

Every year, the lime juice industry discards mountains of peel, a waste product that turns out to be a treasure trove of health-promoting compounds. Among them are limonin, a bitter limonoid with anti-cancer potential, and hesperidin, a flavonoid known for its antioxidant and anti-inflammatory properties. But extracting these compounds usually requires harsh chemicals and high energy. This study flips the script by using a green approach: a simple ethanolic-aqueous solution, renewable ethanol as a bio-solvent, and mild conditions.

Researchers systematically varied ethanol concentration, pH, and temperature to optimize the extraction. They used response surface methodology to map the sweet spot and UHPLC-MS/MS to precisely measure the yields. The results were striking: ethanol concentration and temperature were the main drivers, while pH had little influence. The winning formula was 80% ethanol at pH 7 and 50°C, yielding 2.072 mg/g of limonin and 3.353 mg/g of hesperidin from the peel powder.

This isn't just about chemistry—it's about sustainability. By turning food waste into a valuable source of bioactive compounds, the process saves energy and uses a renewable solvent. The study demonstrates that green extraction can be both efficient and practical, offering a win-win for industry and environment.

Key Points

• Green extraction with 80% ethanol at pH 7, 50°C
• Yields 2.072 mg/g limonin and 3.353 mg/g hesperidin
• Ethanol and temperature matter most; pH has little effect