INNOVATING DAIRY ALTERNATIVES: THE PRODUCTION AND EVALUATION OF PLANT-BASED YOGURT SUBSTITUTES | ابتكار بدائل الألبان: إنتاج وتقييم اللبن النباتي

Background The demand for plant-based food alternatives has increased in recent years, driven by growing health consciousness, and environmental concerns. Among these alternatives, plant-based yogurt has become increasingly popular as a dairy substitute. Objectives The primary objective of this study is to evaluate the impact of blending four distinct plant-based milk varieties (oat milk (OM), almond milk (AM), coconut milk (CM), and quinoa milk (QM)) at varying concentrations on the physicochemical properties and sensory and nutritional characteristics of plant-based yogurt following fermentation with lactic acid bacteria. Methodology Various plant-based milks were selected for yogurt production and blended at different ration (T1: 30% OM, 30% AM, 20% CM, 20% QM, T2: 30% OM, 20% AM, 40% CM, 10% QM, T3: 50% OM, 25% AM, 15% CM, 10% QM, T4: 30% OM, 30% AM, 10% CM, 30% QM, T5: 25% OM, 20% AM, 35% CM, 20% QM). The blended plant-based milk were fermented by using (Lactobacillus Bulgaricus and Streptococcus Salivarius subsp. Thermophilus) at 45°C for 6 h. To avoid the Syneresis phenomena stabilizers, pectin and xanthan gum and their mixture was added. The quality of the milk was assessed through pH measurements, total titratable acidity, and zeta potential particle size and polydispersity index were also measured to ensure the stability of the formulations. Blended plant-based yogurt were evaluated for their viscosity and sensory evaluations and acceptability index. Moreover, the nutritional composition of the blended plant-based yogurts was analyzed. Results The plant-based milk was successfully extracted and blended in different ratios. Fermentation ended when the pH reached 4.6. Before fermentation, the acidity ranged from 0.04% to 0.6% as lactic acid, increasing to 0.15%–0.2% during fermentation. T1 had the highest acidity due to its 30% oat and 30% almond milk, while T2 had the lowest with 40% coconut milk and 30% oat milk. Stabilizer addition influenced zeta potential and particle size. Xanthan gum alone significantly improved zeta potential and reduced particle size in T1 and T2 compared to pectin alone or their combination. However, pectin and xanthan gum together further reduced particle size and enhanced stability in T3, T4, and T5. T5, with 35% coconut and 25% oat milk, was the densest and thickest, whereas T1 had the lowest viscosity. Sensory analysis showed that T3 and T5 scored highest in appearance and viscosity, while T5 had the highest overall acceptance. Nutritionally, T1 had the lowest calorie content (49 kcal), while T1, T3, and T4 had the highest protein content (1.2%–1.3%). Discussion Higher acidity in T1 is likely due to increased fermentable sugars in oat and almond milk, while T2's lower acidity may be attributed to coconut milk’s lower sugar content. Stabilizers influenced texture, with xanthan gum improving stability and the pectin-xanthan combination further enhancing viscosity. Sensory results aligned with physicochemical findings, with T5’s balanced composition (coconut, oat, almond, quinoa) yielding optimal mouthfeel and texture, leading to higher acceptance. The low-calorie content of T1 may appeal to health-conscious consumers, while T1, T3, and T4’s higher protein content suggests nutritional benefits. Overall, formulation significantly affected fermentation, stability, and acceptability, highlighting the potential of optimized plant-based yogurt. Conclusions In this study, oat, almond, coconut, and quinoa milk were combined to successfully create blended plant-based yogurt. It is possible that this plant-based yogurt will be a good substitute for dairy yogurt, especially for customers who are vegan, lactose intolerant, or intolerant to dairy proteins. Upgrading formulations for commercial use and increasing production should be the main goals of future research.