Publication: Elsevier
DOI: https://doi.org/10.1016/j.foodhyd.2019.105221
The effect of 0.1 M NaOH as a solvent and blending with pre-gelatinized maize starch on the foaming properties of laboratory extracted total zein and total kafirin were determined. Both total zein and total kafirin in 0.1 M NaOH were found to have higher foaming capacity (up to 118% foam volume increase) compared to their non-foaming (0% foam volume increase) properties in water. Blending with pre-gelatinized maize starch reduced the foam volume but increased the foam stability to more than 24 h. Total zein and total zein-pre-gelatinized starch blends had relatively higher foaming capacity than total kafirin and total kafirin-pre-gelatinized starch blends probably because zein was more surface active (more negative zeta potential value) than kafirin. However, total zein and total zein-pre-gelatinized starch blend foams were less stable with time than total kafirin and total kafirin-pre-gelatinized starch blend foams. This is possible because total kafirin, having higher amount of cysteine, can have higher degree of cross linking than total zein to form stronger lamellae. The foam microstructure, bubble size and foam film thickness are related to the foaming capacity and foam stability. Larger bubble size corresponded with higher foaming capacity but smaller bubbles and thicker film lamellae corresponded with lower foaming capacity and improved stability. The improved foam formation of total zein and total kafirin in 0.1 M NaOH solution compared to water could be due to the higher degree of deamidation in 0.1 M NaOH, which in turn would make them more surface-active and could increase their solubility/dispersibility.
related Publications
Joint Publications
Dynamic Oral Texture Properties of Selected Indigenous Complementary Porridges Used in African Communities
Child malnutrition remains a major public health problem in low-income African communities, caused by factors including the low nutritional value of indigenous/local complementary porridges (CP) fed to infants and young children. Most African children subsist on locally available starchy foods, whose oral texture is not well-characterized in relation to ...
Joint Publications
Pasting, flow, thermal and molecular properties of maize starch modified with crude phenolic extracts from grape pomace and sorghum bran under alkaline conditions
This study determined the effects of phenolic extracts from grape pomace and sorghum bran, reaction time and washing with aqueous ethanol on the pasting, flow, thermal and molecular properties of maize starch. The starch modification was carried out under alkaline conditions. The phenolic extracts increased the peak viscosity of the ...
Joint Publications
Storage stability of encapsulated ascorbyl palmitate in normal and high amylose maize starches during pasting and spray dryin
This study determines storage stability and release of encapsulated ascorbyl palmitate in normal and high amylose maize starch by pasting and spray drying. The amount of ascorbyl palmitate released was analysed in the stored samples (dark cupboard, and under UV light at a temperature of 40 °C for 12 weeks) and their ...