Abstract This study evaluated the influence of temperature and β-galactosidase concentration on lactose hydrolysis and on the composition of pasteurized goat milk. Goat milk was pasteurized at 75 °C/15 s and cooled to 10 °C and 30 °C, received 0 (control); 0.04%; 0.07%; 0.20% (v/v) β-galactosidase and was incubated for 5 h, followed by enzymatic inactivation at 85 °C. The hydrolysis degree, pH and acidity were evaluated hourly. Physico-chemical parameters were determined after hydrolysis. The maximum hydrolysis degree (100%) has been reached in 4 h when using 0.07% and 0.20% lactase concentrations at 30 °C; however, the minimum hydrolysis percentage of 70% has been reached at 10 °C for all lactase concentrations tested since 1 h of incubation. The degree of hydrolysis and the total acidity of pasteurized goat milk increased with temperature. Low lactase concentrations resulted in an increase in protein levels, total casein, density, total and defatted dry extract. Therefore, combination of low lactase levels and hydrolysis at 10 °C promoted positive changes in lactose-free pasteurized goat milk. This study was the first reporting the changes resulting from enzymatic hydrolysis in the composition of pasteurized goat milk.

Abstract This study aimed to the replacement of sodium chloride (0.4 to 1.6%) by potassium chloride (0.2 to 0.8%) in French bread formulation and evaluate its effect on physical, physicochemical and sensory characteristics. For the preparation of bread was used a factorial design 22 with 4 factorial points and 3 central points, totaling 7 experiments. The physical and physicochemical parameters analyzed were: specific volume, moisture, color of the peel and crumb, pH, acidity and texture profile, sodium and potassium. The sensory evaluation of bread was performed using quantitative descriptive analysis, with 12 sensory terminologies. Response variables of salty taste and sensory chewiness generated statistically significant models. The results indicated optimal ranges of 0.2 to 0.5% of potassium chloride, and 1.0 to 1.6% for sodium chloride, and proved the technical feasibility of producing French bread with 50% salt reduction (174.09 mg.50 g–1), compared to a standard formulation of 1.88% (306.5 mg.50g-1) salt, corresponding to the prognosis recommended by the National Health Surveillance Agency.