Thermal studies on protein isolates of white lupin seeds (Lupinus albus)
- 359 Downloads
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 ΔH values, which in general decreased with increasing values of pH and ionic strength in the experimental conditions of extraction.
KeywordsLupinus albus TG DSC Protein isolate SDS-PAGE
The authors wish to thank Predilecta Foods (São Lourenço do Turvo, SP, Brazil), CAPES Foundation (Brazil) for financial support, Ms Ana Paula Ferreira for help with lupin seed protein isolate extraction and Ms Maraiza Aparecida Silva for her technical assistance. The authors and this Foundation have no conflict of interest in regards to this manuscript.
- 2.Saio KM. Microstructural approach to legume seeds for food uses. Food Str. 1993;12:333–41.Google Scholar
- 3.Bunger A, Soto D, Wittig E, Cariaga L, Hernández N. Development of food products containing lupin fiber and their effects in elderly people. In: 9th International Lupin Conference. Klink-Muritz. Canterbury: International Lupin Association; 2000. p. 438–439.Google Scholar
- 4.Champ M. Benefits of pulses in human diet. In: 4th European Conference of Grain Legumes: toward the sustainable production of healthy food, feed and novel products. Cracow: AEP, European Association for grain legume research; 2001. p. 109–113.Google Scholar
- 12.AOAC. Official methods of analysis. 16th ed. Arlington: Association of Official Analytical Chemists; 1995.Google Scholar
- 18.Neves VA, Lourenço EJ, Silva MA. Extração, isolamento e fracionamento da proteína de tremoço (Lupinus albus) var Multolupa. Alim Nutr. 2001;12:115–30.Google Scholar
- 35.Ferreira RB, Freitas RL, Teixeira AL. The structure of Lupinus seed storage proteins. Recent developments. Curr Topics Plant Biol. 2003;4:139–50.Google Scholar