Application of Cassia Grandis Galactomannan as a Natural Stabilizer and Fat Replacer in Yogurts: Physicochemical, Rheological, and Sensory Evaluation

The search for natural and sustainable alternatives for food products, especially dairy ones, is increasing in response to the consumer demand for healthier products. In this context, natural products, for example, those sourced from plants, have been extensively studied considering their potential biotechnological application. The galactomannan extracted from Cassia grandis seeds depicts as a promising additive, acting as both a stabilizer and a fat replacer. This study investigated the influence of this galactomannan (0.1–0.4%, w/v) on the physicochemical, rheological, and sensory properties of yogurts formulated with different types of milk (whole, skimmed, and semi-skimmed). The addition of galactomannan significantly improved elasticity and viscosity, enhancing the stability of the yoghurt’s gel network and reducing syneresis (0 ± 0.00 mL) compared to control groups (0.20 ± 0.00 to 0.30 ± 0.00 mL). Rheological analysis confirmed the maintenance of a robust viscoelastic profile with increasing concentrations of galactomannan (G' > G"). Yoghurts with 0.2% galactomannan received good acceptance, although the slightly yellow coloration and higher elasticity reduced scores for yogurts made with skimmed (2.74 ± 1.24) and semi-skimmed milk (2.48 ± 1.49). Purchase intention was highest for the whole milk yoghurt with 0.2% galactomannan (3.24 ± 1.27), suggesting that the interaction between galactomannan, fat, and casein micelles favored an optimized texture and pleasant sensory profile. These findings support the use of C. grandis galactomannan as a sustainable ingredient for healthier dairy formulations with maintained consumer acceptability.