Optimization of pectin extraction from quince peels (Cydonia oblonga) using ultrasound-assisted extraction with citric acid

Valdez-Arana J.D.C.; Ramos A.H.; Orué B.S.; Diego R.J.; Pósito Baca M.A.; Delgado-Soriano V. · Applied Food Research (2026) · DOI: 10.1016/j.afres.2026.102461

Resumen

Quince peels (Cydonia oblonga) are an agro-industrial by-product with high potential as a source of pectin. This study aimed to optimize pectin extraction from quince peel meal using ultrasound-assisted acid extraction and evaluate the effects of extraction conditions on yield and physicochemical properties. Quince peels were dried, ground, and characterized prior to extraction. Ultrasound-assisted extraction (UAE) was performed under different pH conditions and process parameters, and the influence of these factors on pectin yield, equivalent weight, methoxyl content, and degree of esterification was evaluated using response surface methodology (RSM). The results showed that quince peel powder contains significant amounts of carbohydrates and dietary fiber, confirming its suitability as a raw material for pectin recovery. Citric acid was selected as the most suitable acidifying agent for the extraction of bioactive compounds. The pectin yield obtained by ultrasonic extraction ranged from approximately 10.1 to 17.8% depending on the extraction conditions. The statistical models adequately described the effects of the evaluated variables, showing a significant influence of pH and quadratic effects on the extraction responses. Although the highest pectin yield was obtained under more acidic conditions (pH 1.5) when UAE was combined with heating, the optimal extraction conditions selected by the desirability approach corresponded to pH 2.5, as this condition provided a favorable balance between extraction efficiency and preservation of the key physicochemical characteristics of the extracted pectin. Additionally, the combination of ultrasonics with heat treatment improved extraction efficiency, achieving pectin yields of up to 47.0% at pH 1.5, compared to ultrasonic extraction alone. These results demonstrate that UAE, particularly when combined with heating, is an efficient and sustainable alternative for pectin recovery from quince peel waste. This contributes to the valorization of agro-industrial by-products and the development of a more sustainable extraction approach for them.

Instituciones: Universidad Nacional Agraria La Molina