Lactitol production

Reaction of olefin oxides (epoxides) to produce poly(oxyalkylene) ether derivatives is the etherification of polyols of greatest commercial importance. Epoxides used include ethylene oxide, propylene oxide, and epichl orohydrin. The products of oxyalkylation have the same number of hydroxyl groups per mole as the starting polyol. Examples include the poly(oxypropylene) ethers of sorbitol (130) and lactitol (131), usually formed in the presence of an alkaline catalyst such as potassium hydroxide. Reaction of epichl orohydrin and isosorbide leads to the bisglycidyl ether (132). A polysubstituted carboxyethyl ether of mannitol has been obtained by the interaction of mannitol with acrylonitrile followed by hydrolysis of the intermediate cyanoethyl ether (133). 

Figure 8.8 Internal mass transfer resistance and catalyst deactivation concentration profiles inside a catalyst particle-lactose hydrogenation to lactitol and by-products (sponge Ni).

Very precise kinetic experiments were performed with sponge Ni and Ru/C catalysts in a laboratory-scale pressurized slurry reactor (autoclave) by using small catalyst particles to suppress internal mass transfer resistance. The temperature and pressure domains of the experiments were 20-70 bar and 110-130°C, respectively. Lactitol was the absolutely dominating main product in all of the experiments, but minor amounts of lactulose, lactulitol, lactobionic acid, sorbitol and galactitol were observed as by-products on both Ni and Ru catalysts. The selectivity of the main product, lactitol typically exceeded 96%. 

Figure 12.2. Reaction scheme (1-3, 4b) for formation of lactitol and by-products.

Figure 12.3. Lactose hydrogenation at 120°C and 50 bar on Ru/C (main product lactitol, by-product with maximum lactulose). Fit of model (1-3, 4b).

Hydrogenation of lactose to lactitol on sponge itickel and mtheitium catalysts was studied experimentally in a laboratory-scale slurry reactor to reveal the true reaction paths. Parameter estimation was carried out with rival and the final results suggest that sorbitol and galactitol are primarily formed from lactitol. The conversion of the reactant (lactose), as well as the yields of the main (lactitol) and by-products were described very well by the kinetic model developed. The model includes the effects of concentrations, hydrogen pressure and temperature on reaction rates and product distribution. The model can be used for optinuzation of the process conditions to obtain highest possible yields of lactitol and suppressing the amounts of by-products. 

Both dietary and endogenous ammoniagenic substrates are removed from the intestinal lumen by the osmotic cathartic action of nonabsorbable disaccharides such as lactulose and lactitol. These compounds are currently the main therapeutic agents for chronic HE. The efficacy of oral lactulose for the treatment of HE has been established in controlled trials [41-43]. Besides having a cathartic effect, lactulose lowers the colonic pH as a result of the production of organic acids by bacterial fermentation. The decrease in pH creates an environment that is hostile to the survival of urease-producing intestinal bac-... 

Catalyst deactivation often plays a central role in manufacturing of various alimentary products. Sugar alcohols, such as xylitol, sorbitol and lactitol, are industrially most commonly prepared by catalytic hydrogenation of corresponding sugar aldehydes over sponge nickel and ruthenium on carbon catalysts (5-10). However, catalyst deactivation may be severe under non-optimized process conditions. 

Xylose hydrogenation gave xylitol as a main product (selectivity typically over 99 %) and arabinitol, xylulose and xylonic acid as by-products, in lactose hydrogenation, the main product was lactitol (selectivity typically between 97 and 99 %) and lactulitol, galactitol, sorbitol and lactobionic acid were obtained as by-products. 

Lactose has a sweetish taste, and is used extensively in the pharmaceutical industry. It is the second most widely used compound and is employed as a diluent, filler or binder in tablets, capsules and other oral product forms, a-lactose is used for the production of lactitol, which is present in diabetic products, low calorie sweeteners and slimming products. As lactose is only 30 per cent as sweet as sugar it is used as a sugar supplement, and also in food and confectionery. It is used in infant milk formulas. 

Lactitol 40 is a disaccharide that has been used in the management of hepatic encephalopathy, a major neuropsychiatric complication of both acute and chronic liver failure. It has mild laxative properties and is used to reduce the production and absorption of gut-derived neurotoxic substances symptomatic of hepatic encephalopathy. Although long considered a first-line pharmacological treatment, there is a lack of sufficient evidence to support lactitol s efficacy and continued use when weighed against other suitable therapeutic alternatives such as oral antibiotics <2006MI94>. 

Milk and products thereof (including lactose), except lactitol, and whey used for making distillates or ethyl alcohol... 

Another reason for consuming sugar-free products is the belief that refined sugar is in some way unhealthy. Tooth friendly claims are highly specific the product must be tested to see that it does not cause a fall in pH during eating, and this system requires the use of a specialised pH electrode strapped to the teeth of a volunteer. To pass this test the product must be free of any fermentable carbohydrate and acids - this does have the odd effect in that some products which contain concentrated fruit juice fail the test and have to be re-formulated. The calorific values accepted by the authorities are not universal. The current position in the European Union is that the polyols are only partially absorbed to the extent of 2.4 kcal g 1 as opposed to 4 kcal g 1 if they are completely absorbed. For example, the polyol lactitol has the following accepted values ... 

The ingredients usually used in these products are polyols such as sorbitol, maltitol, lactitol, isomalt, erythritol and polydextrose ... 

Lactose and maltose, readily available in large quantities from whey and starch, have some application in the form of their reduction products maltitol and lactitol, which are sweetening agents. 

Lactitol occurs as white orthorhombic crystals. It is odorless with a sweet taste that imparts a cooling sensation. It is available in powdered form and in a range of crystal sizes. The directly compressible form is a water-granulated product of microcrystalline aggregates. 

Polyhydric alcohols include xylitol, mannitol, sorbitol, maltitol, lactitol and isomalt. Although these products generally have a lower sweetening power than sucrose, they also have fewer calories, only 2.4 kilocalories per gram of dry matter. They also do not cause tooth decay, and for this reason are mainly used in anti-cariogenic chewing gum and confectionaries. However, polyhydric alcohols also have an undesirable laxative effect that becomes apparent with excess consumption and as a function of individual constitution. Eor this reason, the European Union does not allow the beverage industry to use polyhydric alcohols as a sweetener. 

Another nonabsorbable disaccharide used in the treatment of hepatic encephalopathy is lactitol ( 6-galactosidosorbitol). Compared to lactose, lactitol has the advantage of higher palatability and fewer side effects (e.g., flatulence). Ammonia production in... 

The use of lactulose, a nonabsorbable disaccharide, (and lactitol, not available in the United States) is standard therapy for both acute and chronic HE. Lactulose, when administered orally, passes through the gastrointestinal tract and reaches the colon unchanged. For patients unable to take lactulose orally or via tube administration it may be administered as an enema. In the colon, lactulose lowers colonic pH and exerts a cathartic effect. Fermentation of lactulose by bacteria present in the colon results in the production of organic acids, decreasing colonic pH to approximately 5. ... 

Sucrose and sorbitol are commonly used in frozen surimi processing. However, sucrose imparts a sweet taste to surimi products, which is undesirable to the consumer (Sych et al., 1990 Auh et al., 1999 Sultanbawa and Li-Chan, 2001). Thus, the use of other cryoprotectants to reduce sweetness but exhibit the equivalent cryoprotective effect is required. Auh et al. (1999) used highly concentrated branched oligosaccharide mixture (HBOS) as cryoprotectant in fish protein. An addition of HBOS resulted in the remainder Ca -ATPase activity of actomyosin extracted from Alaska pollock after freeze-thawing the best stabilization effect of HBOS was observed at a concentration of 8%. Sych et al. (1990) studied the cryoprotective effects of lactitol dehydrate, polydextrose, and palitinit at 8% (w/w) in cod surimi in comparison with an industrial control (sucrose/sorbitol, 1 1). The... 

Non-absorbable disaccharides such as lactulose and lactitol are still routinely used to deoease ammonia production in the gut despite a lack of adequate controlled clinical trials. In the case of lactulose, the ammonia-lowering effect appears to involve increased fecal nitrogen excretion by facilitation of the incorporation of ammonia into bacteria as well as a cathartic effect. Antibiotics such as neomycin have ttaditionaUy been used to lower blood ammonia by inhibition of ammonia production by intestinal bacteria. However, neomycin therapy is associated with significant toxic side effects and is increasingly being replaced by alternative antibiotics such as rifaximin. 

The reduction of intestinal ammonia synthesis can also be achieved by the administration of non-absorbable disaccharides-like lactulose and lactitol or antibiotics like neomycin, paramomycin, metronidazole or rifaximin. Lactulose exerts several effects (1). acidification of the intestinal content resulting in a reduction of ammonia absorption and net movement of ammonia from the blood into the bowel and (2). reduced bacterial production of ammonia in the colonic lumen due to environmental changes with promotion of the growth of non-urease producing bacteria and (3). the cathartic effect. The daily dose of lactulose is between 30 and 60 g per day. The goal is to obtain 2-3 soft bowel movements per day. Recently lactulose has been proven to be effective even in patients with minimal HE (Prasad et al., 2007). 

Figure 3 gives data for the preparation of lactitol palmitate, as an illustration of the influence of the molar ratio polyalcohol/fatty acid on the composition of the reaction product. According to this pro-... 

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