Syrups, defined

This model is representative for the conditions described in the previous section, except for the mode of administration which can be oral, rectal or parenteral by means of injection into muscle, fat, under the skin, etc. (Fig. 39.7). In addition to the central plasma compartment, the model involves an absorption compartment to which the drug is rapidly delivered. This may be to the gut in the case of tablets, syrups and suppositories or into adipose, muscle or skin tissues in the case of injections. The transport from the absorption site to the central compartment is assumed to be one-way and governed by the transfer constant (Fig. 39.7a). The linear differential model for this problem can be defined in the following way ... 

Present Label Implicitly Applies to Harvested Pollen. For beekeepers who use oxytetracycline for medication, the present label (Table I) is explicit in defining the proper use and precautions that need to be followed when honey is to be harvested and marketed for human consumption. Presumably the label implicitly applies to pollen collected for human consumption as well. This does, however, pose an interesting question - if fresh pollens were collected in pollen traps placed at the hive entrance of medicated colonies before the 4 week restriction elapsed, as stated on the use label for collecting marketable honey, would the oxytetracycline be transferred by the honey bee to the pollen. To answer the question field colonies were medicated by feeding freshly prepared solutions of medicated sugar syrup for several weeks at recommended and twice recommended levels. Immediately at the end of medication, and every 3 to 4 days thereafter, pollen traps were sampled and emptied to trap samples of pollen freshly collected by the foraging bees. 

Corn syrup solids (C5Hi2O5)n 2 (CAS. Reg. No. 68131-37-3) are defined by the FDA as dried glucose syrups (21 CFR 168.121) in which the reducing sugar content (DE) is 20.0 or higher. Corn syrup solids are presently under GRAS review along with other sweeteners and table syrups. 

Maltodextrins and corn syrup solids are most often defined by their dextrose equivalence (DE). DE is a measure of the degree of hydrolysis of the starch molecule which compares the reducing power of the sugar groups as compared to the reducing power of an equal weight of glucose present. 

Oligo- and higher saccharides are produced extensively by acid-and/or enzyme-catalyzed hydrolysis of starch, generally in the form of syrups of mixtures (12). These products are classified by their dextrose equivalency (DE), which is an indication of their molecular size and is a measure of their reducing power with the DE value of anhydrous D-glucose defined as 100. 

Glucose syrups, also known as com syrups in the United States, are defined by the European Commission (EC) as a refined, concentrated aqueous solution of D(+)-glucose, maltose and other polymers of D-glucose obtained by the controlled partial hydrolysis of starch (Howling, 1984). Glucose syrups were fust manufactured industrially in the nineteenth century by acid hydrolysis of starch. Hydrochloric acid was normally used, because sulphuric acid caused haze in syrups due to insoluble sulphates. The source of starch can vary in the United States corn is widely used, whereas in other parts of the world wheat, potato and cassava starch are also employed. Acid hydrolysis of starch is still used today. The method is non-specific, but if conditions are tightly controlled, it is possible to make products with a reasonably consistent carbohydrate profile. 

The GRAS affirmation contained in 21 CFR, Section 184.1444, defines maltodextrins as non-sweet, nutritive saccharide polymers consisting of D-glucosyl units linked primarily with alpha-1,4 bonds and having a DE less than 20. The document has been modified to include maltodextrins derived from potato starch as GRAS.8 In 1992, more than 328 million pounds (149x 106 kg) of maltodextrins and com syrup solids were produced in the United States from various starch sources.9... 

The most widely used immobilized enzyme process involves the use of the enzyme glucose isomerase for the conversion of glucose to fructose in com syrup (Carasik and Carroll 1983). The organism Bacillus coagu-lans has been selected for the production of glucose isomerase. The development of the immobilized cell slurry has not proceeded to the point where half-lives of the enzyme are more than 75 days. A half-life is defined as the time taken for a 50 percent decrease in activity. Such immobilized enzyme columns can be operated for periods of over three half-lives. 

This is the place to start, since most often, analytical chemists are trying to help solve someone else s problem. We need to define the solute and its matrix as well as the nature of the analytical problem. For example, in the world of pharmaceuticals, there are raw material identification and purity determinations, in-process testing, dosage-form determinations, content uniformity, dissolution testing, stability studies, bioavailability, pharmacokinetics, and drug metabolism, to name a few. Each of these analytical problems has its own specific requirements. The matrix can be a raw material, granulation, tablet, capsule, solution, lotion, cream, syrup, dissolution medium, blood serum, urine, or various body tissues and fluids. Similar definitions can be described for virtually any industrial area and problem set. These definitions will help select sample preparation, separation, and detection techniques. 

Liquorice is a slightly unusual example of a starch gel instead of separating the starch, wheat flour is used directly. It is also a product where brown sugars and treacle are used. Liquorice paste is typically made from treacle, wheat flour, liquorice extract and caramel. Caramel in this context means the brown colour produced from sugar and not a form of toffee. Industrial caramel is made by the action of ammonium hydroxide on a carbohydrate, typically glucose syrup. The resulting product is not well defined chemically, and for this reason its use is recommended to be limited to 0.2% maximum. 

The quality of the product is defined in terms of the d.e., pH, buffer capacity, and content of dry substance, and of certain special specifications related to specific uses. An example of such a specification is the degree of inversion of sucrose that is attained when a hard candy is made by boiling a mixture of sucrose and the specimen of com syrup almost to dryness under very carefully controlled test-conditions. If... 

The Department of Agriculture has defined maple syrup as a food product containing not more than 35% water and weighing not less than 11 lbs. to the gallon. Sucrose constitutes 95 to 97.5% of maple syrup on dry basis. 

Starch hydrolysis products with a DE lower than 20 are defined by food legislation as maltodextrins, while those with a DE value higher than 20 are classified as glncose syrups. 

Chemically homogeneous dispersions are defined here as dispersions where the dispersed phase and the continuous phase have chemical compositions with important similarities. Examples of such systems are honey, where we have saccharide crystals dispersed in a concentrated syrup, or semi-solid fat, which consists of solid triglyceride crystals dispersed in a solution of liquid triglycerides. 

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