Functional and structural properties of gliadin as influenced by pH, extraction protocols, and wheat cultivars

• Published in: International journal of biological macromolecules 2023-04, Vol.234, p.123484-123484, Article 123484
• Main Authors: Rani, Monika, Siddiqi, Raashid Ahmad, Sharma, Ritika, Gill, Balmeet Singh, Sogi, Dalbir Singh
• Format: Article
• Language: English
• Subjects: Emulsifying properties; Emulsions - chemistry; Foaming properties; FTIR; Gliadin; Gliadin - chemistry; Hydrogen-Ion Concentration; Hydrophobic and Hydrophilic Interactions; pH-solubility; Surface hydrophobicity; Triticum - chemistry
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2023.123484

Gliadin, owing to its low cost, ease to extract, high foaming capacity, easily available and high surface hydrophobicity, has found a wide range of applications both in the food and pharmaceutical sectors. The functional and structural characteristics of gliadin extracted with four extraction protocols from six wheat cultivars were investigated in this study. The surface-active properties of gliadin protein as a function of pH, extraction protocols, and wheat cultivars were compared, including solubility, zeta-potential, foaming properties, emulsion properties, surface hydrophobicity and secondary structure. Overall gliadin extracted using different extraction protocols and from different wheat cultivars was found to be higher in β-turns (24.88–37.91 %), followed by β-sheet (12.81–22.37 %), α-helix (15.13–20.70 %) and lower in random coil (6.53–9.08 %). Varied pH ranges, wheat cultivars, and different extraction protocols were found to have a substantial impact on solubility, zeta potential, foaming stability, emulsion capacity and surface hydrophobicity. The foaming capacity was observed to be more influenced by extraction protocols than wheat cultivars. Emulsion stability showed statistically significant (p ≤ 0.05) influence between the wheat cultivars, and a non-significant (p ≥ 0.05) difference among extraction protocols. The functional properties of freeze-dried gliadin extracted using different protocols were found to be pH-dependent. A comprehensive understanding of how the structural, surface active and functional properties of gliadin are influenced by the extraction protocols and wheat cultivars will enable us to understand the gliadin better and broaden its use for both food and non-food applications. [Display omitted] •Gliadin functional properties were evaluated as a function of pH, cultivars, and extraction protocols.•Different pH, genotypes, and extraction protocols had a strong impact on the functional properties of gliadin.•Extraction protocols and genotypes influenced the secondary structural components of gliadin.•Emulsion stability was strongly influenced by genotypes but not by the extraction protocol.