Rheological properties and sensory characteristics of set-type soy yogurt

Area of Science:

• Food Science
• Microbiology
• Sensory Science

Background:

• Soy yogurt is a dairy-free alternative, but often suffers from a characteristic 'beany' flavor.
• Probiotics can enhance the nutritional profile of fermented foods.
• Understanding the impact of probiotics on soy yogurt's physicochemical and sensory properties is crucial for product development.

Purpose of the Study:

• To evaluate the effect of inulin or raffinose/glucose supplementation on probiotic soy yogurt quality.
• To assess the viability and metabolic activity of probiotic organisms during storage.
• To determine the impact on rheological, sensory, and flavor profiles of soy yogurt.

Main Methods:

• Soy milk was supplemented with inulin or raffinose/glucose and fermented to produce soy yogurt.
• Probiotic viability, organic acid production, and aldehyde content were measured over 28 days at 4°C.
• Rheological properties (viscosity, pseudoplasticity) and sensory attributes (flavor, texture, mouthfeel) were evaluated.

Main Results:

• Supplementation increased bacterial population and lactic acid production.
• Probiotic bacteria effectively metabolized aldehydes, significantly reducing the beany flavor.
• Probiotic yogurts exhibited higher viscosity and pseudoplasticity compared to controls.
• Sensory evaluation revealed a preference for control yogurts due to lower viscosity and better mouthfeel.

Conclusions:

• Inulin or raffinose/glucose can enhance probiotic soy yogurt fermentation and mitigate beany flavor.
• While improving some physicochemical properties, probiotic addition negatively impacted sensory preferences related to texture.
• Further research is needed to optimize probiotic soy yogurt formulations for both health benefits and consumer acceptance.