These studies are essential, because there is a lack of information on the effect of cooking on proteins (albumins, globulins,
prolamins, glutelins, and phaseolin) and certain essential elements (Fe and Cu) associated with proteins, especially in the bean cultivars consumed in Brazil (common and black beans).
The four major types of endosperm proteins in wheat include
Prolamines, Albumins, Gliadins and Glutenins (Shewry et al., 1992; Rogers, 2001).
To extract all four protein fractions (albumin, globulin,
prolamin and glutelin) completely, four saline extraction processes were necessary, i.e., three repetitions to extract the albumin + globulin fractions, along with three alcohol extractions to obtain the
prolamin fraction and seven alkaline extractions to obtain the glutelin fraction, as shown in Figure 2.
Elkhalifa and El Tinay (1995) determined the IVPD of the protein fractions of sorghum dough and found that the IVPD of protein fractions of the low-tannin cultivar increased as a result of fermentation; in the case of the high-tannin sorghum cultivar, IVPD increased during the six hours of fermentation for the albumin, globulin and
prolamin fractions; then decreased for the remaining period.
Chen, "Convenient fabrication of electrospun
prolamin protein delivery system with three-dimensional shapeability and resistance to fouling," ACS Applied Materials and Interfaces, vol.
[15], it was concluded that the treatment increase the quantity of
prolamin in all the treated cake, while the quantity of globulin, albumin and glutelin were reduced.
After removing albumin and globulin, the residue was extracted with 80% alcohol, and the
prolamin fraction was obtained as freeze-dried precipitate by adding a 3-fold volume of acetone and centrifuging at 4,500 r/min for 15 min.
Prolamin and glutelin had a property as highly hydrophobic proteins that insoluble in the water (Damodaran, 1996).
Valuable information has been collated from the EU Framework study 'Protall', which has shown that allergens known to trigger acute reactions following contact and processing along the gastrointestinal tract have structural features in common and belong almost exclusively to the
prolamin, cupin and cysteine protease protein families (8).