People are getting more conscious about the relationship between food and health. Consequently, industry looks for new alternatives to develop food with good acceptance and with ingredients able to improve health. Soy, prebiotics such as oligofructose and inulin have a great application potential in food industry due to their functional properties. The aim of this work was to determine, using the Surface Response Methodology, the best conditions to the development of a soy yogurt supplemented with oligofructose and inulin. A 3³ incomplete design was used, having oligofructose (%), inulin (%) and fermentation time (h) as independent variables, and pH and titrable acidity as responses. Regression analysis showed that models obtained were predictive. The optimization pointed out for the formulation containing 14.24% of oligofructose, 4.43% of inulin and 6 hours, as the best conditions to make soy yogurt. This formulation presented pH value of 4.6 and acidity of 0.37%. The chemical compostion was 16.2% of carbohydrates 2.01% of fat; 3.54% of protein; 0.40% of ash; and 77.85% of moisture. Calcium, iron and sodium content were 37; 0.99 and 15mg/100g, respectively. Therefore, oligofructose and inulin may be used to supplement soy yogurt, resulting in a product with functional ingredients.
yogurt; soy; oligofructose; inulin; surface response methodology
