Abstract:
Fat replacers have been developed to produce low-calorie foods due to the association of fat-rich diet
to lifestyle diseases. Teff (an underutilized and under-researched cereal), and maize starch pastes
modified with stearic acid could be used as fat replacers because of their reduced gelling ability and
higher viscosity. The effects of teff and maize starch pastes modified with stearic acid on the
rheological properties, microstructure, freeze–thaw, and high temperature stability of low-calorie
mayonnaise type emulsions (LCMTE) were investigated. Starch suspensions (10% w/v) containing
stearic acid (1.5%) were pasted and used to prepare LCMTE with 50 and 80% oil replacement.
LCMTE with modified teff and maize starches had lower yield stress and viscosity and larger oil
droplets compared to LCMTE with unmodified teff andmaize starches. Increasing oil replacement
level (50–80%) increased the viscosity. LCMTE with maize starch had higher yield stress and
viscosity and smaller oil droplets than LCMTE with teff starch. All samples showed shear thinning
behavior (n < 1). All the LCMTE were more stable to freeze–thaw cycles and high temperature
storage than full fat mayonnaise. At 50% oil replacement, unmodified and modified teff andmaize
starch with stearic acid could produce LCMTE. When the oil content replacement was further
increased to 80% only the LCMTE with modified starches were similar to the full fat. The LCMTE
made with unmodified teff and maize starches (especially those with 80% oil replacement) did not
flow like a mayonnaise compared to LCMTE made with stearic acid modified starches.
