Structural and functional properties of pectin extracted from African star apple

Abstract

Pectin is primarily derived from citrus fruits and apple pomace and is used in the food industry as an emulsifier, thickener, gelling agent, stabilizer, and viscosity enhancer. Despite exploring other potential sources of pectin, available information on the functional properties of African star apple (ASA) (Chrysophyllum albidum) pectin and its structural composition is limited. This study investigated the relationship between the structure and function of ASA-isolated pectin sourced from two regions in Ghana. Proton Nuclear Magnetic Resonance (NMR) and monosaccharide composition analysis revealed a methyl-esterified pectin with a significant arabinose content of ∼ 20 % and 16 % for ASA-CR and ASA-VR pectin, respectively. Furthermore, scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies indicated the amorphous irregular, and porous nature of ASA pectin. Functionally, ASA pectin demonstrated the ability to retain about 3–4 g of water per gram, with substantial emulsion activity and stability compared to commercial citrus pectin. The rheological analysis demonstrated the pseudoplastic behaviour of ASA pectin with good viscoelasticity. ASA pectin exhibits functional attributes similar to commercial citrus pectin, making it a potential alternative source for food applications.