CARBOHYDRATE ANALYSIS

The wide industrial and pharmaceutical applications of carbohydrates and their polymers require analytical proficiency to meet these demands. These can be some of the most demanding analytical requests we get.

In some cases, liquid chromatography (LC) using refractive index (RI) detection as a concentration sensitive detector can be useful. In other cases, light scattering (LS) detection for mass sensitive analysis can also be useful. Any number of stationary liquid chromatographic phases are available to separate carbohydrate analytes.

Carbohydrate analysis can be a relatively simple procedure if a monosaccharide, disaccharide or polysaccharide exists in a pure form within an uncomplicated aqueous system. Any quantitative interest in sugars coexisting with polysaccharides held in chemically complex system however, requires important considerations affecting the overall analytical strategy.

One of the most important standards for carbohydrate quantitation is predicated on the basis of the dextrose equivalent or so-called DE value. Using this rationale, glucose also known as dextrose, is employed as an analytical standard and basis for the measurement of other mono-, di- and polysaccharides. For example, the analysis of standard monosaccharidic glucose concentrations can serve as an analytical basis for determining the equivalent number of grams of glucose existing in 100 grams of corn starch which represents a polymeric form of glucose. In other words, an unknown carbohydrate concentration is expressed as though it was an equivalent weight of free glucose.

Total carbohydrate in a sample can be readily quantified using the anthrone reaction. This will determine the amount of reducing or non-reducing sugar in a sample relative to any specific carbohydrate sample index desired, but dextrose is typically used for most applications.

If a carbohydrate of interest happened to be inulin, then it may be desirable to use a representative of its constituent monomer in the form of fructose as the analytical benchmark instead of dextrose. The method relies on a total conversion of monosaccharidic constitutents within a sample into their furfural derivatives that can be accurately detected at microgram/ mL concentration levels.

For complex interrelationships involving polymeric carbohydrates along with monosaccharides, it may be necessary to independently quantify LC-MALLS results for polymeric characterization of a starch followed by an independent evaluation and assay of monosaccharide levels to obtain the full picture free monosacharridic carbohydrate levels with reference to the corresponding metabolism of a starch polymer.

CANINE SEIZURES AND EVIDENCE OF MYCOTOXINS

Based on unprecedented circumstances for poor grain preservation and quality, CAT’s experience suggests grain-based ingredients in some dog (pet) foods may incite adverse events such as seizures. After years screening for toxins in domestic human and imported foods, CAT can provide a screening assay for some pet owners with dogs that develop periodic but unexplained seizures.

Veterinarians and others offer a variety of explanations for seizures and there are many clinical tests that supposedly address the problem. Depending on the breed, some animals are thought to have a hereditary predisposition for seizures but the cause is largely unknown or idiopathic. The reality for some canine breeds is that they may be ultra-sensitive to mycotoxins rather than being genetically predisposed to have seizures.

This screening survey for mold toxins in dog food provides a “likely” versus “unlikely” evaluation that a food contains mycotoxic agents. If putative evidence of mycotoxins is detected, it will be reported. This might justify a change in food with the object of avoiding future seizures or indicate that the seizure could be due to a cause other than mold toxins. Apart from well known indicators of mycotoxin presence, lesser known mycotoxins called tremorgens commonly occur when other mycotoxins are present. These produce uncoordinated movements, a stiff backwardly arched neck, salivation with licking and drooling, and panting as a seizure diminishes whereupon the dog becomes increasingly aware of its surroundings. Interestingly, these symptoms mimic those in canines found to be sensitive to natamycin which is approved for antifungal uses in shredded cheese products and human consumption.