Elucidation of the formation of CO2 in culinary dry products

Byline: I. Kruse (1), Ursula Wolfensberger (2), Raphael Badoud (3), K. Eichner (1) Keywords: Key wordsaDry culinary products; CO2 formation; 13CO2; Galacturonic acid; Strecker degradation; Decarboxylation Abstract: aThe formation of CO.sub.2 in tomato powder, chosen as an example of a dry culinary product, was investigated at room temperature and at low values of water activity (a .sub.w). CO.sub.2 formation correlated well with parameters that represent the beginning and progression of the Maillard reaction. In the absence of O.sub.2, CO.sub.2 formation decreased. Pectin and depolymerized pectin did not influence CO.sub.2 formation while galacturonic acid (GalA) had a large effect. Determination of 13.sup.CO.sub.2 in low-moisture model systems revealed that CO.sub.2 was not formed by decarboxylation of GalA alone. Only a small proportion of [1- 13.sup.C]glycine and GalA was degraded by the Strecker pathway however, glucose reacted with the labelled amino acid forming 13.sup.CO.sub.2 which amounted to over 90% of the total CO.sub.2 formed. Therefore, CO.sub.2 could be used as an early indicator for the beginning of the Maillard reaction in dry culinary products. Author Affiliation: (1) Institut fur Lebensmittelchemie der Universitat Munster, Gorrensstrasse 45, D-48149 Munster, Germany, DE (2) Nestle R &amp D Center, Kemptthal, CH-8310 Kemptthal, Switzerland, CH (3) Nestec Ltd., Nestle Research Center, Vers-chez-les-Blanc, P.B. Box 44, CH-1000 Lausanne 26, Switzerland, CH Article note: Received: 28 October 1996