Techno-functional properties of quality protein maize (QPM) (Zea mays L.) protein concentrates

Abstract

Nowadays, new strategies and alternatives are being implemented to improve the protein quality of foods containing essential amino acids, like quality protein maize (QPM). The techno-functional properties of protein concentrate from QPM maize: Sac Beh (SB), Chichen Itza (ChI), and Blanco Uxmal (BU); non-nixtamalized (NN) and nixtamalized (N), were evaluated in the present work. The non-nixtamalized varieties showed higher amounts of protein in the QPM ChI (86.81%) and nitrogen solubility of 64.94% as the pH increased to 9. The emulsifying capacity was higher at pH 5 (60.74%). The non-nixtamalized SB samples showed higher foaming stability (1.82%) at pH 7, and the non-nixtamalized BU samples had higher foaming capacity at pH 5 (60.74%). Water holding capacities ranging from 1.2 to 3.13 g/g were achieved. The non-nixtamalized QPM concentrates had higher water and oil holding capacities. There was a predominance of elastic character over viscous character (G' > G'') in all treatments behaving as weak gels, which were affected in alkaline conditions by decreasing the modulus value. The techno-functional properties were affected by the processing method. These results could be beneficial for providing a better understanding of the properties of QPM proteins, allowing innovative ways of utilising these proteins as an ingredient in food systems.