Process for preparing fermented whey beverage with lactulose

摘要

The invented process for preparing fermented whey beverage with lactulose of the present invention is carried out in such a manner that thickened whey without proteins is subjected to alkalization with the addition of a hydroxide aqueous solution to pH value of 11.0 +/-0.2. Subsequently it is subjected to partial isomerization at a temperature ranging from 70.0 +/- 2 degC. Then it is rapidly cooled down to 20 +/- 3 degC and neutralized by the addition of an acid. Raw isomerate is then heated to 50 to 70 degC and after about 1 hour past addition of a mixture of activated coal and diatomaceous earth is filtered and cooled down. The refined isomerate is of light-yellow color, sweetish flavor and contains 6.0 to 9.0 percent by weight of lactose and 2.0 to 5.0 percent by weight of lactulose. The refined isomerate is mixed with 1 to 3 parts of a sweet whey, pasteurized, inoculated with lactic (acid) fermentation bacterium inoculate and fermented under optimal conditions for the given microorganism at pH value in the range of 4.2 to 4.7. The thus obtained product is turbid has light-yellow color, acid taste with characteristic smell of fermented dairy products. The number of live microorganisms in 1 ml of the product is higher than 10e6 and the final product contains 5.0 to 7.0 percent by weight of lactose, 0.5 to 2.0 percent by weight of lactulose and 0.5 to 1.0 percent by weight of lactic acid. It can be further flavored, aromatized, colored with natural dyes, optionally to enrich with vitamins or other biologically active substances. The package volume is selected such as to achieve by its consumption an intake of a recommended dose of lactulose in an amount of about 3 g a day.