Mid infrared as a tool to study the conformational structure of starch and proteins with oil addition during gelatinization

Zeineb Nhouchi , Eliot Botosoa (1) , Christine Chèné (2) , Romdhane Karoui (1)

1 BioEcoAgro - Equipe 9 - Structure-function relationship at the service of the reasoned formulation of food and ingredients
2 ADRIANOR

The impact of varying fat and gelatinization on the starch and protein secondary structures was investigated in slurry and batter systems using mid-infrared (MIR) spectroscopy. Following the addition of both thickening agent and oil, the absorbance ratio R1: 1022 cm-1/995 cm-1 ranged from 0.99 to 1.1 and from 0.85 to 0.89 for slurries and batters, respectively. The level of the beta-turn structure decreased for both slurries (from 20.2 to 17.9%) and batters (from 18.8 to 16.4%) with the thickening agent addition. Similarly, oil incorporation reduced the amount of the beta-turn structure for both slurries (from 20.2 to 9.1%) and batters (from 18.8 to 16.4%). This result confirms the increase of the hydrophobicity of unfolded proteins, the loss of the beta-turn structure and the increase of the beta-sheet. The gelatinization increased the level of alpha-helix structure and reduced the percentage of beta-sheet structure for all slurry and batter systems in the Amide III regions.

Mots clés: Pound cake; Starch structure; Protein secondary structure; MVAG; MIR

Domaines: Sciences du Vivant [q-bio]; Sciences de l'environnement

Zeineb Nhouchi, Eliot Botosoa, Christine Chèné, Romdhane Karoui. Mid infrared as a tool to study the conformational structure of starch and proteins with oil addition during gelatinization. LWT - Food Science and Technology, 2022, 157, pp.113093. ⟨10.1016/j.lwt.2022.113093⟩. ⟨hal-03653090⟩