Physicochemical Characteristics of Black Rice–Based Yoghurt Stabilized by Red Palm Oil Pickering Emulsion
Developments on plant-based yoghurt alternatives are increasing since they are sustainable, lactose-free and functional foods. However, maintaining desirable stability and quality is still a challenge. The study investigated the impact of red palm kernel oil (RPO) Pickering emulsion on black rice-based yogurt. RPO was added at 0, 1.75, 3.5, 4.0 and 5.0% levels and then fermented with lactic acid bacteria. The results showed that incorporation of RPO had significant effect on total soluble solids, pH, colour, antioxidant activity, moisture and ash content. pH increased from 3.91 to 5.05 with increasing RPO concentration while titratable acidity did not change. Carotenoids contribution increased lightness and yellowness of RPO with b* values from 1.21 to 11.74. The antioxidant activity was the highest at 4% RPO (139.82 mg TE/g DW) but the total phenolic content was not significantly affected. Moisture content decreased after RPO addition, while ash content increased with higher RPO concentration. The viability of lactic acid bacteria was high (10.18 to 11.23 log CFU/mL) in all the treatments. To summarize, 4% RPO had the best combination of antioxidant activity, microbial viability and physicochemical characteristics.