Hygroscopic foods

Lactitol. Lactitol (4-0-/ -D-galactopyranosyl-D-sorbitol), is a synthetic sugar alcohol produced on reduction of lactose, usually using Raney nickel. It can be crystallized as a mono- or di-hydrate. Lactitol is not metabolized by higher animals it is relatively sweet and hence has potential as a non-nutritive sweetener. It is claimed that lactitol reduces the absorption of sucrose, blood and liver cholesterol levels and to be anticariogenic. It has applications in low-calorie foods (jams, marmalade, chocolate, baked goods) it is non-hygroscopic and can be used to coat moisture-sensitive foods, e.g. sweets. 

Differences in the hygroscopicity of various salts may also be used to estimate aw. Samples of the food are exposed to a range of crystals of known aw if the aw of the sample is greater than that of a given crystal, the crystal will absorb water from the food. 

Complexes of maltose with urea, thiourea, imidazole, methanol, 2-oxazolidinone, N,N-dimethylformamide, and hexamethylphosphoric triamide have been described.131 These complexes were noncrystalline and hygroscopic. Such complex-forming reactions could be valuable in the preservation of food flavors during the dehydration process. Sugars have been shown to complex with ethylenediamine.133,133 The nature of the complex has been suggested to be that of a proton-transfer type, in which the carbohydrate moiety is the proton donor and the amine is the proton acceptor. 

ANTTCAKING AGENTS. Some products, particularly food products that contain one or more hygroscopic substanoes, require the addition of an anticaking agent to inhibit formation of aggregates and lumps and thus retain tile free-flowing characteristic of the products Calcium phosphate, for example, is commonly used in instant breakfast drinks and lemonade and other soft-dnnk mixes. 

Improve the flow properties. Powders, especially some food powders, show a poor flow behavior. Often these powders are sticky, hygroscopic and may contain fats, all of which have a negative effect on the powder flow properties. By agglomeration of the powders, the flow properties usually improve substantially. 

The free base is unstable, and two derivatives of thiamin are commonly used in food enrichment and pharmaceutical preparations thiamin chloride hydrochloride (generally known simply as thiaminhydrochloride) and thiamin mononitrate. The mononitrate is less hygroscopic than the chloride hydrochloride and is the preferred form for food enrichment. There is considerable difficulty in interpreting much of the literature on thiamin requirements, because many authors quote mg of thiamin, without specifying whether it was as the free base, the chloride hydrochloride, or the equivalent amount of free base. Because the Mr of free thiamin is 266.4, and that of the chloride hydrochloride is 337.3, this confusion can result in errors of the order of 26%. 

Mannitol is widely used in pharmaceutical formulations and food products. In pharmaceutical preparations it is primarily used as a diluent (10-90% w/w) in tablet formulations, where it is of particular value since it is not hygroscopic and may thus be used with moisture-sensitive active ingredients. 

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