GAS-CHROMATOGRAPHIC DETERMINATION OF CARBON-DIOXIDE IN NONFAT DRY MILK DURING NONENZYMATIC BROWNING REACTION

Carbon dioxide formation in non‐fat dry milk during accelerated non‐enzymic browning reaction was determined by gas chromatography. Carbon dioxide content in the headspace of the sample bottle increased as the non‐enzymic browning reaction increased. Non‐fat dry milk containing added 0, 15 or 30 g kg−1 lysine in the air‐tight serum bottle was stored at 55, 65 or 75°C. The coefficients of variation for reflective spectroscopic brown colour measurement and GC carbon dioxide determination were 1.37% and 1.30%, respectively. The average correlation coefficient between brown colour development and carbon dioxide formation for the nine samples during storage was 0.96. The simple, fast and reproducible gas chromatographic carbon dioxide determination method could be used to study non‐enzymic browning reactions in foods or to complement other analytical methods in measuring the non‐enzymic browning reaction. Copyright © 1990 John Wiley & Sons, Ltd