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Antinutrients (ANs) interact with proteins changing its behavior and may affect Maillard reaction (MR). This work aimed to study the effect of phytic acid, tannic acid, and saponin on asparagine-glucose MR. The effect of AN concentration (0-1 mM) and reaction time (3-30 min at 150 °C) on the formation of melanoidins and acrylamide was determined. Other MR compounds were analyzed by gas chromatography and nuclear magnetic resonance. The ANs effect on asparagine-glucose thermal behavior was studied by differential scanning calorimetry. Results showed that ANs increase the melanoidins formation. Acrylamide content increased in saponin and phytic acid presence. The volatile profile was similar among the samples and formed mainly by pyrazines (>50%). ANs affect glucose's melting point, however, only phytic acid and saponin affect asparagine and glucose thermal behavior. The results presented in this work are important for food science and the industry to control MR in processed foods., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Saponins are known for their bioactive and surfactant properties, showing applicability to the food, cosmetic and pharmaceutical industries. This work evaluated the saponins effects on Kluyveromyces lactis β-galactosidase activity and correlated these changes to the protein structure. Enzyme kinetic was evaluated by catalytic assay, protein structure was studied by circular dichroism and fluorescence, and isothermal titration calorimetry was used to evaluate the interactions forces. In vitro enzymatic activity assays indicated an increase in the protein activity due to the saponin-protein interaction. Circular dichroism shows that saponin changes the β-galactosidase secondary structure, favoring its protein-substrate interaction. Besides, changes in protein microenvironment due to the presence of saponin was observed by fluorescence spectroscopy. Isothermal titration calorimetry analyses suggested that saponins increased the affinity of β-galactosidase with the artificial substrate o-nitrophenyl-β-galactoside. The increase in the enzyme activity by saponins, demonstrated here, is important to new products development in food, cosmetic, and pharmaceutical industries., (Copyright © 2019 Elsevier Ltd. All rights reserved.)