Formulation of a Yogurt Co-fermented with Carrot Juice (<i>Daucus carota</i>) and Evaluation of Its Nutritional Potential in the Fight Against Avitaminosis A

Abstract

The WHO recommends the formulation and use of functional foods in response to persistent public health problems. There is a renewed interest in developing new products based on milk and fruit and vegetables to tackle certain public health problems. Avitaminosis A is a disease that affects thousands of people worldwide, particularly in sub-Saharan Africa. In order to contribute to the fight against Avitaminosis A in Cameroon, this study aims to formulate a yoghurt rich in provitamin A and to evaluate its nutritional potential. It is a yoghurt co-fermented with carrot juice which has the characteristics of a functional food. Five samples of co-fermented yoghurt were formulated and coded respectively YN, YC1, YC2, YC3, YC4 for the plain yoghurt made from 100% milk, then with increasing percentages of carrot juice substitution (70, 80, 90, 100% (V/V)) to reconstitute the milk. Physicochemical (pH and titratable acidity), nutritional (water content, total ash, crude protein, total lipids, total carbohydrates, crude fibers, vitamin C, β-carotene), sensory (color, taste, consistency, smell and general acceptability), microbiological (total coliforms, yeasts, molds and salmonella) analyses were carried out on the different formulated samples. From the results obtained, it appears that carrot juice significantly affects (p<0.05) the pH, titratable acidity and dry matter of the different yogurts. The incorporation of this juice leads to an increase in protein, total sugar, crude fibers, ash, vitamin C and β-carotene content, but a decrease in lipid content (p<0.05). Refrigerated storage at 4°C did not significantly (p<0.05) change the pH and acidity of the yoghurts. Microbiological analysis revealed that all co-fermented yoghurts were fit for consumption. The results of the general acceptability showed that YN and YC3 yoghurts were the most appreciated by the panelists. Principal Component Analysis (PCA) showed that the yoghurt with 90% carrot juice (YC3) was the most correlated with β-carotene, vitamin C and crude fibers. Also, this sample has contents of 3.91% protein, 5.03% crude fibers, 3.20 mg β-carotene, 4.26 mg vitamin C. From the point of view of sensory analysis and PCA, this yoghurt was the best and could be recommended in the diet to contribute to the fight against vitamin A deficiency.