ARS | Publication request: DETECTING CORN SYRUP IN BARLEY MALT EXTRACTS

Submitted to: Cereal Foods World
Publication Type: Abstract Only
Publication Acceptance Date: June 30, 2001
Publication Date: N/A

Technical Abstract: Methods to detect adulteration of barley (Hordeum vulgare L.) malt extract with corn syrup were evaluated. Twelve samples of commercially available 2-rowed and 6-rowed malting barleys were malted. Extracts prepared from the finely ground malts were analyzed for their 13C/12C ratios, expressed as delta 13C, and for their concentrations of protein and sugars. The 13C/12C ratios differentiated corn syrup from malt extract. By calculating the mean values for the barleys, it was determined that a delta 13C less than -24.3 parts per thousand indicated that the malt extract had been adulterated with corn syrup (99 percent confidence). Protein concentrations less than 4.5 percent (2-rowed malt) or less than 5.0 percent (6-rowed malt) of the extracts also indicated probable adulteration with corn syrup, which is devoid of protein. Differences in sugar concentrations between the malt extracts and corn syrup also indicated probable mixtures. These findings were confirmed by analysis of extracts from composite 2-rowed and 6-rowed barley malts that had been mixed with known quantities of corn syrup. The regressions for delta 13C, protein concentration, and most sugar concentrations against percent dilution with corn syrup in the mixtures were significant.