Thermal studies on protein isolates of white lupin seeds (Lupinus albus)

• Published in: Journal of thermal analysis and calorimetry Vol. 108; no. 1; pp. 141 - 148
• Main Authors: Fontanari, Gustavo Guadagnucci, Martins, José Manuel, Kobelnik, Marcelo, Pastre, Iêda Aparecida, Arêas, José Alfredo Gomes, Batistuti, José Paschoal, Fertonani, Fernando Luis
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-04-2012; Springer
• Subjects: Agronomy. Soil science and plant productions; Analytical Chemistry; Biological and medical sciences; Chemistry; Chemistry and Materials Science; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Generalities and techniques; Inorganic Chemistry; Measurement Science and Instrumentation; Physical Chemistry; Polymer Sciences; Seeds; Thermodynamics; SDS-PAGE; TG; Protein isolate; DSC; Differential scanning calorimetry; Seeds; Gel electrophoresis; Conformational changes; Leguminosae; Dicotyledones; Angiospermae; Plant origin; Lupinus albus; Spermatophyta; Fodder crop; Thermal analysis
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-011-1898-6

This study used TG, DSC, and SDS-PAGE techniques to study protein isolates (PIs) in the powder form obtained from lupin seeds flour
Lupinus albus
. Different methods of preparing PIs were tested, resulting in final products that were different only in relation to the yield and protein content. The results of the protein analysis by SDS-PAGE showed that the same protein fractions were present in the lupin seeds and in the obtained PIs. This result shows that the process of extraction was not damaging to the composition of the original protein. On the other hand, the results of the thermal analysis (DSC and TG–DTG curves) obtained for the different PIs, led to the detection of changes in the protein conformation through the Δ
H
values, which in general decreased with increasing values of pH and ionic strength in the experimental conditions of extraction.