Starch Analysis in Paper

Paper is increasingly recycled. In 2005, the recycling rate reached 51.5%. Current AF PA guidelines target the return of 55% consumer waste paper into new paper production by 2012. Various processes have been developed to de-ink waste papers that carry a wide range of inks and coatings.293,294 Most de-inking is accomplished by the use of surfactants, dispersion and flotation. 

Since starch is biodegradable, it has found use as filler in polymers, such as extruded films applied to paperboard for use in packaging.295,296 The starch is incorporated in granular form,297 as an octenylsuccinate derivative298 and in other forms. Starch-based blown films are prepared from starch-poly(ethylene-co-acrylic acid) formulations.299 

Oxidized corn starch may contain AOX materials from the chlorination of associated lipids. Avoidance of AOX discharges in paper mill effluents is an environmental priority.300 

The starch content in paper is determined by a TAPPI test method.301 Special methods are needed to assay starch in the presence of other adhesives.302 Starch on the paper surface is determined by ATR (attenuated total reflection) Fourier transform IR spectroscopy.303 New methods are being developed by the International Standards Organization (ISO).304 

Various refinements of starch content analysis have been reported. The methods are based on starch hydrolysis, followed by polarimetry,305 high-pressure liquid chromatography306 or reaction with glucose oxidase/peroxidase.307,308 An iodine reaction can be used to determine the botanical origin of starch.309 The molecular weight distribution is determined by size-exclusion chromatography.310,311 

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