Amaranth proteins foaming properties: film rheology and foam stability. Part 2

BOLONTRADE, A.J.; SCILINGO, A.A; AÑON, MARÍA CRISTINA

COLLOIDS AND SURFACES B-BIOINTERFACES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016

0927-7765

In this work the influence of pH and ionic strength on the stability of foams prepared with amaranth protein isolates was analyzed. The behaviour observed was related to the physicochemical and structural changes undergone by amaranth proteins as a result of those treatments. The results obtained show that foams prepared at acidic pH were more stable than the corresponding to alkaline pH. At pH 2 the foams presented higher times and more volumes of drainage. This behaivour is consistent with the characteristic of the interfacial film, which show a higher visvoelasticity and a greater flexibility at acidic pH than alkaline pH value, which in turn increased by increasing the concentration of protein in foaming solution. It is also important to know that the present of insoluble proteins is not necessarily detrimental to the proteins of the foam. Detected changes in the characteristics of the interfacial film as in the foam stability have been attributed to the increased unfolding, greater flexibility and net charge of amaranth proteins at acidic conditions.