Biochemical and physical–chemical characterisation of leaf proteins extracted from Cichorium endivia leaves. (1st July 2022)

• Record Type: Journal Article
• Authors: Ducrocq, Maude; Morel, Marie-Hélène; Anton, Marc; Micard, Valérie; Guyot, Sylvain; Beaumal, Valérie; Solé-Jamault, Véronique; Boire, Adeline
• Is Part Of: Food chemistry. Volume 381(2022)
• Publication Date: 2022-07-01
• Subjects: Leaf protein concentrate -- RuBisCO -- UV–visible spectroscopy -- Protein solubility; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2022.132254
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: RuBisCO is the major protein of LPC extracted from Cichorium endivia leaves. LPC contains all the essential amino acids in appropriate amount as per AFSSA. SDS-PAGE reveals RuBisCO large and small chains and a disulphide linked large chain dimer. LPC is highly soluble (>90%) in aqueous buffers above pH 6. Minor compounds of LPC affect the physical–chemical properties of RuBisCO. Abstract: This study provides a detailed characterisation of a leaf protein concentrate (LPC) extracted from Cichorium endivia leaves using a pilot scale process. This concentrate contains 74.1% protein and is mainly composed of Ribulose-1, 5-BISphosphate Carboxylase/Oxygenase (RuBisCO). We show that the experimentally determined extinction coefficient (around 5.0 cm −1 g −1 L depending on the pH) and refractive index increment (between 0.27 and 0.39 mL g −1 ) are higher than the predicted ones (about 1.6 cm −1 g −1 L and 0.19 mL g −1, respectively). In addition, the UV–visible absorption spectra show a maximum at 258 nm. These data suggest the presence of non-protein UV-absorbing species. Chromatographic separation of the concentrate components in denaturing conditions suggests that RuBisCO SC may be covalently bounded to few phenolic compounds. Besides, the solubility of LPC proteins is higher than 90% above pH 6. Such high solubility could make LPC a good candidate as a functional food ingredient.