Application of enzymatically hydrolyzed-lactose milk and whey in some dairy products

الملخص EN

Kluyveromyces lactis β-Galactosidase was used to hydrolyze lactose in milk (28 and 56 % hydrolysis) and in whey (26.25 and 52.5% hydrolysis).

Hydrolyzed-lactose milk was used for the production of ice cream and stirred flavored yogurt while the hydrolyzed-lactose whey was used for the production of a soft drink (whey beverage).

The added sucrose to these products was decreased to compensate the sweetness that gained as a result of lactose hydrolysis.

The percentages of saved sucrose in ice cream were 6.53 and 13.06 % for 28 and 56 % hydrolyzed-lactose samples, respectively.

Sensory evaluation of ice cream sweetness showed non-significant difference (p≤0.05) between the hydrolyzed-lactose samples (28 and 56 % hydrolysis) and the untreated sample except for texture where a significant difference was observed between the 56 % hydrolyzed-lactose ice cream and the control sample.

The percentages of sucrose saving in stirred flavored yogurt were equal to 7.42 and 14.84 % for 25.83 and 51.66 % lactose hydrolysis, respectively, whereas in whey beverage they were equal to 3.25 and 6.5 % for 26.25 and 52.5 % lactose hydrolysis, respectively.

Sweetness sensory evaluation of the stirred flavored yogurt and whey beverage showed non-significant differences among hydrolyzed-lactose samples and the untreated samples.