Process For Making A Shelf-Stable Milk Based Beverage Concentrate

Abstract

A concentrate, system and low-temperature process for preparing a shelf-stable milk concentrate that does not require ultra-high temperature thermal processing for control of the microbiology of the product is disclosed herein. The method preferably incorporates aseptic technology and the enzymatic reduction of lactose to control water activity. The method preferably includes the enzymatic conversion of the lactose in the milk to its component sugars glucose and galactose, which preferably changes the colligative properties of the concentrate, decreases the amount of free water, and reduces the osmolarity.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]The Present Application claims priority to U.S. Provisional Patent Application No. 61 / 075,015, filed on Jun. 24, 2008, which is hereby incorporated by reference in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not ApplicableBACKGROUND OF THE INVENTION[0003]1. Field of the Invention[0004]The present invention relates to processes for making shelf stable milk beverages.[0005]2. Description of the Related Art[0006]For millennia man has tried unsuccessfully to devise a method for preserving milk which would retain the nutrients and qualities of fresh milk. Roman soldiers subsisted on rations made from dried milk using primitive sun drying techniques. Later technology developed by Gail Borden (1858) resulted in sweetened condensed milk which could be preserved for years using simple concentration methods utilizing water activity as the microbiological control point. More modern milk processing and packaging t...

AI Technical Summary

Benefits of technology

[0012]The present invention is preferably a method for preserving milk using a concentration method that incorporates aseptic technology and the enzymatic reduction of lactose to control water activity. The method includes the enzymatic conversion of the lactose in the milk to its component sugars glucose and galactose. This reaction changes the colligative properties of the concentrate, decreases the amount of free water, and reduces the osmolarity.

[0013]Milk (0.2-3.25% fat) is concentrated using low-temperature, vacuum evaporation to produce a 3.0-4.2× concentrate. As the concentration of the milk increases, so does the viscosity. At this point, the addition of lactase enzyme at a rate of 0.01-5 ml per liter results in very rapid decrease in the lactose concentration resulting in significant changes in the colligative properties of the concentrate. The viscosity decreases and the milks ability to be further concentrated improves dramatically. Further concentration can be accomplished by further treatment in temperature controlled vacuum pans or by the addition of non-fat dry milk solids using high shear.

[0014]The hydrolysis of lactose requires the incorporation of equal moles of water and lactose to yield one mole each of glucose and galactose. Neutral lactase enzyme (2600-4000 units per liter (MaxiLact)) is injected into the milk concentrate to hydrolyze the lactose sugar into glucose and galactose. Preferably, a minimum of 70% of the lactose must be hydrolyzed and the desired level is in the 98% range. This process reduces water activity by decreasing the amount of water and by increasing the number of moles of sugar dissolved in the concentrate. Since lactose solubility is about 21.6%, a 4× concentration of milk is the practical limit of concentration using conventional technology. Further concentration results in graininess, crystallization and viscosity increases. Furthermore, the insoluble lactose must be subtracted from the water activity equation since it is no longer dissolved.

Problems solved by technology

At this point, the addition of lactase enzyme at a rate of 0.01-5 ml per liter results in very rapid decrease in the lactose concentration resulting in significant changes in the colligative properties of the concentrate.

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