Influence of Kefir Grain Concentration on the Nutritional, Microbiological, and Sensory Properties of Camel Milk Kefir and Characterization of Some Technological Properties

This study aimed to manufacture kefir from camel milk using an extensive production system with different amounts of kefir grains, as well as to highlight their nutritional, sensorial, and technological characteristics. During processing, the pasteurization of camel milk, the addition of three doses of kefir grains (2%, 5%, and 10%), and incubation for 18 h were carried out. The microbiological and nutritional properties of the camel milk, kefir grains, and resulting kefirs were assessed. The sensory evaluation and technological processes involved in the production of the selected kefir were then carried out. The results showed that the chemical composition of the camel milk was as follows: fat: 41.7 ± 3.18 g/L; protein content: 37.82 ± 0.66 g/L; ash: 8.92 ± 0.61 g/L; dry matter: 114.21 ± 0.11 g/L; and lactose: 41.3 ± 0.21 g/L. Kefir grains were acidic and moist and contained low fat content (0.02 ± 0.01). The total aerobic flora in camel milk was FAMT 4.77 × 104 CFU/mL. The bacterial load of lactic acid bacteria in the camel kefir prepared with 10% kefir grains was 5.1 ± 0.6 log10 CFU/mL, while the yeast and mold load was 4.24 ± 0.83 log10 CFU/mL. The amount of kefir grains present had a significant effect (p < 0.05) on pH, acidity, and viscosity and improved the protein content, resulting in higher nutritional quality. According to a sensory evaluation, the ranking test showed that the best camel kefir can be produced by the addition of 2% kefir grains. It was the most appreciated by 73% of the tasters based on its physicochemical, microbiological, and sensory characteristics. All obtained camel kefirs were able to fulfill the Codex Alimentarius requirements, ensuring their safety and quality, with overall improvements in taste, texture, and acceptability. A phenotypic and morphological study of lactic acid bacteria isolated from the selected kefir (CK 2%, 18H) showed that these bacteria are Gram+, citrate+, catalase−, shell−, and rod-shaped. All the strains isolated showed good lipolytic and proteolytic activity, with areas of proteolysis between 8 and 15 mm. These strains were also revealed to have antibacterial activity and good acidifying and texturizing effects.