Effects of Chickpea Protein on Carbohydrate Reactivity in Acrylamide Formation in Low Humidity Model Systems

Abstract

Asparagine and reducing sugars are the principal precursors of acrylamide in foods. Their main sources in pastries are flour and hen egg yolks. One method of reducing acrylamide content in food may be to add a chickpea protein preparation. The aim of the study was to determine the effects of the chickpea protein preparation on the thermodynamic properties of carbohydrates and the amount of acrylamide formed in low humidity model systems. In the studied systems, the type and amount of acrylamide precursors and humidity were designed to reflect the parameters typical of shortcrust cookies. In the study, the highest amounts of acrylamide were formed in the reaction between asparagine and fructose and the lowest in the reaction between asparagine and sucrose. Furthermore, the addition of chickpea protein to the analyzed carbohydrate-asparagine model systems reduced the content of acrylamide formed during baking at 180 °C regardless of the type of carbohydrate. The greatest acrylamide reduction (41%) was found in the model system containing fructose.

Keywords: acrylamide; asparagine; carbohydrates; chickpea protein isolate; differential scanning calorimetry; low humidity model systems; melting point.

Figure 1

Concentration of carbohydrates and free asparagine in model systems with and without 1% chickpea protein preparation: fructose: asparagine (a), fructose–asparagine–1% chickpea protein preparation (a1), glucose–asparagine (b), glucose–asparagine–1% chickpea protein preparation (b1), sucrose–asparagine (c), sucrose–asparagine–1% chickpea protein preparation (c1), before and after baking; lowercase letters—different letters in the same figure indicate significant differences in the content of individual carbohydrates and asparagine within the same model system before and after baking (n = 3; p ≤ 0.05); data are presented as means ± SD.

Figure 2

Changes in acrylamide concentration in carbohydrate–asparagine model systems with 1% chickpea protein preparation, subjected to thermal treatment, depending on carbohydrate type; uppercase letters—different letters indicate significant differences in acrylamide content between systems depending on carbohydrate type regardless of the addition of chickpea protein (n = 3; p ≤ 0.05); lowercase letters—different letters indicate significant differences in acrylamide content in a given model system depending on the addition of chickpea protein preparation (n = 3; p ≤ 0.05); data are presented as mean ± SD.

Figure 3

DSC thermograms for fructose (a), glucose (b), and sucrose (c), with and without the addition of chickpea protein preparation; solid line—sugar without chickpea protein; dotted line—sugar with chickpea protein.