الفهرس 
. IntroductionOnly 14 pages are availabe for public view
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Abstract
Most available lactulose available in markets today is primarily produced through the chemical conversion of lactose under alkaline conditions. Over the past decade, enzymes like GH and cellobiose-2-epimerase have been studied as biocatalysts for the process. They showed promising results in catalyzing the cleavage of the glycosidic bond between the galactose moiety and the glucose moiety in lactose. Aside from enzyme-based production; one of the most significant chemical reaction pathways for the produced of lactulose from lactose in an alkaline medium is the Lobry de Bruyn Alberda van Ekenstein pathway, which is widely utilized in the industry for converting lactose into lactulose for its ability to isomerize lactose into lactulose in mildly alkaline medium with relatively high heat exposure. 5.2. Objective of Current Study Modifying the pH of the skim milk, by increasing it from 6.5 to 7.5, then subjecting it to high heat treatment at 95°C for 2 min or leaving it unheated for 1 hour. Subsequently, the pH was adjusted back to 6.5, and the samples were analyzed to assess the overall milk composition and its lactulose content concentration. 5.3. Most Significant Outcomes 1-Lactulose concentration in skim milk showed a significant rise due to HHT which appeared to be more pronounced as the pH number was elevated from 6.5 to 7.5. 2-Raising pH value for both HHT milk and UH milk from 6.5 to 7.5, led to an extended heat coagulation time at pH number of 7.2. 3-Recorded increase in k-casein dissociation of HHT milk equals 58.7% (of total k-casein content in skim milk). 4-pH value adjustment had no significant influence on total composition of skim milk during HHT, as well as on its ethanol-stability on pH range of (6.2-7.2). 5-HHT (95°C x 2 minutes) led to a significant decrease in CMS. 5.4. Conclusion The alcohol stability and heat coagulation time were influenced by the pH during the high heat treatment of milk samples. Changes in k-casein dissociation, denaturation of whey proteins, and a reduction in the concentration of soluble Ca in the serum were associated with these outcomes. For those who use skim milk powder in applications like recombined milks and heated milk-based beverages, the ability to control lactulose content, ethanol stability and heat coagulation time in defatted milk is crucial. Additionally, this approach could offer a new avenue for increasing lactulose content in milk through its use in lactose isomerization to lactulose, potentially leading to the development of innovative techniques.