Abstract

Ivory Coast is the world’s largest producer of cashew nuts, generating significant amounts of waste that can be used as a source of beneficial natural compounds such as pectin. However, its properties depend on extraction conditions and methods. The aim of this study was to recover pectin from cashew apple pomace (Anacardium occidentale L.) using ultrasound-assisted extraction (UAE). A three-factor, three-level Box–Behnken design coupled with a desirability function was employed to optimize the process. The physicochemical and functional properties of this pectin were analyzed and compared to those of conventional extraction (CE). The results showed that the optimal conditions were 10:1 mL/g (solvent–solid ratio), 40 min (sonication time), and 1.5 (pH), resulting in a maximum yield of 9.54 ± 0.35%, higher than that of CE (7.63 ± 0.53%). The pectin characterization showed that ultrasound-assisted extraction increased the equivalent weight, methoxyl content, anhydrouronic acid content, and degree of esterification. However, the conventionally extracted pectin exhibited the best water holding capacity, emulsion activity, and foaming capacity, as well as emulsion and foaming stability. Moreover, cashew apple pectin obtained through both extraction techniques was categorized as highly methyl-esterified and showed similarity in structure (Fourier-transform infrared spectroscopy [FT-IR]). Thus, cashew apple pomace could be a valuable source of pectin with interesting functional properties, thereby relieving pressure on currently commercial sources of pectin.

Key words: Anacarduim occidentale, Response surface methodology, Optimization, Ultrasound extraction, highly methyl-esterified pectin, conventional extraction