Maize landrace and post-harvest traits are reflected in the volatile profile and nutritional composition of Italian maize porridge (Polenta): A preliminary study

Abstract

Maize porridge, known as ''polenta'' in Italy, is a global staple food. This study aims to characterize the quality of four Italian flint maize landraces by investigating physical properties and macronutrients composition. By using SPME GC–MS and PTR-ToF-MS we analyzed the flours volatilome and changes in aroma profile post- cooking. Cooking induced the formation of 5 compounds and the loss of up to 25 compounds, primarily through evaporation. Post-cooking, the concentrations of some sulphur compounds (methanethiol, dimethyl sulfide and dimethyl trisulfide), lipid oxidation compounds (2-pentylfuran and hexanal) and Maillard reaction compounds including some aldehydes (nonanal, benzaldehyde, phenylacetaldheyde), pyridine and furans (furfural and furfuryl alcohol) increased. Differences in volatilome and macronutrients contents among landraces were also observed with Marano samples having on average a significantly higher concentration of proteins (13.67 %), while the Nostrano samples had the highest fat content (5.00 %). Fatty acid profile differences were mirrored in the volatilome. Spin flours had the highest level of linoleic acid, leading to elevated levels in cooked polenta due to linoleic acid oxidation. The differences in volatilome and macronutrients contents among the samples confirmed that local landraces are not only important for biodiversity and cultural heritage but also lead to unique aroma compounds profiles.

Keywords

• Flint maize
• Polenta
• Volatilome
• SPME GC-MS
• PTR-TOF-MS