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Comprehensive characteristic of lipid fraction as a distinguishing factor of three lupin seed species
pH-Dependent oligomerisation of γ-conglutin: A key element to understand its molecular mechanism of action
Effect of different oligomerization assemblies of γ-conglutin on its interaction behavior with vitexin
AbstractBACKGROUNDSeveral different factors underlie the molecular mechanisms of phenolic compound‐protein interactions. They include the environmental conditions. In the case of γ‐conglutin, pH conditions translate directly into the adoption of two distinct oligomeric assemblies, i.e. hexameric (pH 7.5) or monomeric (pH 4.5). This paper reports research on the pH‐dependent oligomerization of γ‐conglutin in terms of its ability to form complexes with a model flavonoid (vitexin).RESULTSFluorescence‐quenching thermodynamic measurements indicate that hydrogen bonds, electrostatic forces, and van der Waals interactions are the main driving forces involved in the complex formation. The interaction turned out to be a spontaneous and exothermic process. Assessment of structural composition (secondary structure changes and arrangement/dynamics of aromatic amino acids), molecular size, and the thermal stability of the different oligomeric forms showed that γ‐conglutin in a monomeric state was less affected by vitexin during the interaction.CONCLUSIONThe data show precisely how environmental conditions might influence phenolic compound‐protein complex formation directly. This knowledge is essential for the preparation of food products containing γ‐conglutin. The results can contribute to a better understanding of the detailed fate of this unique health‐promoting lupin seed protein after its intake. © 2023 Society of Chemical Industry.
Physicochemical Characteristics and Technological Properties of Lupinus mutabilis Oil
AbstractThe aim of the presented study is to examine the physicochemical parameters of the lipids present in Lupinus mutabilis seed and to compare the results with the available data for other commonly used vegetable oils. The oil quality indexes, oxidative stability index (OSI), and melting characteristics are examined. Andean lupin oil has remarkably high oxidative stability (OSI = 65 h) comparable to high‐oleic oils counterparts. Quality parameters meet commonly accepted standards, including peroxide value (3.95 meq O2 kg−1) and p‐anisidine value (1.25). The acid number value is 1.85 mg KOH g−1. The iodine value is 110.27 g/100 g, while the enthalpy required to increase the temperature of the sample from −60 to 80 °C is equal to 57.41 kJ kg−1. The beginning of the melting event (Tonset) and the phase transition temperature (Tpeak) values for L. mutabilis seed oil are −29.46 and −22.63 °C, respectively. The presented results indicate the unusually high oxidative stability of the oil obtained from L. mutabilis seeds, which opens up a whole spectrum of application possibilities, e.g., designing blends with other commonly used vegetable oils to enhance their low stability.Practical Applications: The presented results provide insight into physicochemical parameters of the lipid fraction isolated from Lupinus mutabilis seeds. Andean lupin oil has very high oxidative stability, comparable to high‐oleic rapeseed and sunflower oils. Therefore, the identified potential use of the studied oils is, e.g. an additive that can increase the stability of commercial vegetable oils characterized by much lower oxidative stability.