Acetylated Opuntia atropes Mucilage: Physicochemical Characterisation and Application in Low-Fat Yogurt

Mucilage extracted from Opuntia atropes cladodes is a plant-derived polysaccharide with promising techno-functional properties for food applications. Owing to its thickening and stabilizing capacity, cactus mucilage has attracted increasing interest as a natural ingredient in the formulation of reduced-fat dairy products. However, native mucilage may have functional limitations that could be improved through chemical modification. Nevertheless, limited information is available regarding the chemical modification of O. atropes mucilage and its application in fermented dairy systems.

In this study, mucilage was extracted from O. atropes cladodes and subsequently modified by acetylation to improve its functional properties. The extraction process was optimised to obtain mucilage efficiently while reducing solvent consumption. Native and acetylated mucilage samples were characterised through physicochemical analyses and structural evaluation using Fourier transform infrared spectroscopy (FTIR). Finally, the modified polysaccharide was incorporated into low-fat yogurt formulations to evaluate its effects on physicochemical, textural and stability properties.

Acetylation modified the physicochemical and structural properties of the mucilage, affecting its hydration, viscosity and stability. Structural analysis confirmed the successful incorporation of acetyl groups into the polysaccharide matrix. When incorporated into low-fat yogurt formulations, the mucilage improved textural properties and reduced whey separation without adversely affecting key physicochemical parameters of the product. These results indicate that chemical modification can enhance the techno-functional performance of cactus mucilage in fermented dairy systems.

This study offers new insights into the chemical modification of O. atropes mucilage and demonstrates its potential as a natural stabilizer in low-fat yogurt. The findings contribute to the development of plant-based hydrocolloids with enhanced functional properties and support the valorisation of cactus-derived polysaccharides as sustainable ingredients for the formulation of healthier dairy products.