322: Impact of Fermentation Conditions on Physicochemical and Sensory Properties of Plant-Based Yogurts

Introduction

There is a growing demand for plant-based foods. Dairy and meat have been the primary food categories for creating plant-based alternatives. Plant-based yogurts play a significant role in meeting this demand, but challenges remain in mirroring the physicochemical and sensory properties of dairy yogurts. Fermentation conditions are crucial for understanding the production of such alternatives.

Methods

This research aimed to evaluate the effect of different temperatures (39, 42, and 45°C) along with different fermentation times (8, 16, and 24 h), using two plant-based milks (almond and soy) on the physicochemical properties [pH, viscosity (mPa·s), color (L*, a*, b*), dissolved oxygen (mg/L), Brix (°), water-holding capacity (WHC; %), acidity (g of lactic acid/100 mL)], and sensory characteristics (liking) of yogurts. A dairy yogurt (42°C and 8 h) was used as a control. Analysis of Variance (ANOVA), Response Surface Methodology (RSM), and Principal Component Analysis (PCA) were used for statistical analysis (α=0.05).

Results

Soy-based yogurts showed lower pH, higher viscosity, and greater WHC than almond-based yogurts. Fermentation time and temperature affected all parameters, with soy products generally closer to dairy in acidity (2.49–3.93 g/100 mL), viscosity (6,556–13,340 mPa·s), and WHC (41.51–54.69%). Almond-based yogurts exhibited distinct color and pH profiles but lacked comparable viscosity. RSM showed that the viscosity of plant-based yogurts decreased with higher fermentation temperatures and increased (to a maximum) with extended fermentation durations. This trend was more pronounced in almond-based yogurts, where viscosity peaked around 16 h of fermentation. Additionally, pH increased with higher fermentation temperatures and decreased with extended fermentation durations. PCA showed that soy-based yogurts were associated with WHC, viscosity, and L*, while almond-based yogurts were linked to pH and a*. In contrast, the dairy yogurt was primarily associated with Brix and dissolved oxygen levels. Sensory analysis favored soy and dairy yogurts for texture and firmness, reflecting higher WHC and viscosity.

Significance

These findings demonstrate that fermentation conditions and milk type significantly influence yogurt quality, with soy-based formulations showing greater potential to replicate the sensory and physicochemical properties of dairy yogurts. These insights provide valuable guidance for the development of plant-based yogurts that better meet consumer expectations.

Authors: Damir D. Torrico, Jesus Guevara, Michelle M. Betancourt