Multivariate Analysis of the Efficiency of Bio-Actives Extraction from Laboratory-Generated By-Products of Citrus reticulata Blanco

ABSTRACT

A growing demand for sustainable methods to valorize agricultural by-products underscores the need for efficient, green extraction techniques. This study evaluated ultrasound-assisted extraction (UAE) of bioactive compounds from Citrus reticulata Blanco peel and pomace using multivariate analysis across six key metrics: total phenolic content (TPC), flavonoid content, and four antioxidant assays. UAE significantly outperformed conventional extraction (CE), achieving a 207% higher average composite performance score (2.94 vs. 0.95), on the basis of a heatmap-derived SUM(P*) index. The best UAE sample (S9: peel–aqueous–UAE) achieved a score of 5.33 out of 6, compared to 2.01 for the best CE sample (S3), highlighting the superior efficiency of UAE. Principal component analysis (PCA) revealed distinct clustering of UAE samples, confirming their enhanced biochemical profiles. UAE also reduced energy consumption to 0.065 kWh (77% less than CE) while maintaining high antioxidant performance. Fourier transform infrared spectroscopy (FTIR) confirmed functional groups characteristic of phenolics, and ultra-high performance liquid chromatography (UHPLC)–HRMS identified catechin, neohesperidin, and nomilinic acid derivatives as major bioactives. These findings establish a robust, data-driven framework for optimizing sustainable extraction of food-grade antioxidants from citrus residues. This validated UAE approach enables efficient, low-energy recovery of phenolics from citrus waste, offering immediate potential for integration into food, nutraceutical, and cosmetic industry supply chains under circular economy models.

Practical Application: Ultrasound technology may help to recover valuable natural antioxidants from citrus peel and pomace, materials often discarded during juice production. The method uses sound waves to create cavitation, which gently breaks plant cells and releases beneficial compounds more efficiently. These extracts can be used to enrich functional food products or dietary supplements with natural ingredients. By combining this method with multivariate analysis that assesses quality indicators, it becomes easier to identify the most effective processing conditions. This approach may also be useful for food, cosmetic, and nutraceutical industries seeking to reduce waste and develop cleaner, more sustainable products.