Optimal combination of cow and quinoa milk for manufacturing of functional fermented milk with high levels of antioxidant, essential amino acids and probiotics

Abstract The aim of this research was to produce Rayeb milk, a bio-fermented milk product that has important benefits for health and nutrition. The Rayeb milk was divided into five different treatments: T1 from cow milk, T2 from quinoa milk, T3 from a mixture of cow and quinoa milk (50%:50%), T4 from a mixture of cow and quinoa milk (75%:25%), and T5 from a mixture of cow and quinoa milk (25%:75%). As a starting culture, ABT-5 culture was used. The results demonstrated that blending quinoa milk with cow milk increased the total solids, fat, total protein, pH, acetaldehyde, and diacetyl values of the resulting Rayeb milk. Additionally, the total phenolic content, antioxidant activity, minerals, and amino acids—particularly important amino acids—in Rayeb milk with quinoa milk were higher. In Rayeb milk prepared from a cow and quinoa milk mixture, Lactobacillus acidophilus and Bifidobacterium bifidum were highly stimulated. All Rayeb milk samples, particularly those that contained quinoa milk, possessed more bifidobacteria than the recommended count of 106 cfu g−1 for use as a probiotic. Based on the sensory evaluation results, it is possible to manufacture a bio-Rayeb milk acceptable to the consumer and has a high nutritional and health values using a mixture of cow milk and quinoa milk (75%:25% or 50%:50%) and ABT-5 culture.