**3.1 Sensory evaluation and acceptability of vegetable leaf-fortified bread**

Sensory evaluation deals with human sensory perception and their effective responses to food and its components. Sensory evaluation of food products is a function of five major sense organs; the sense of sight, smell, taste, touch, and ear to answer questions related to the preference of the food products under evaluation [53, 54]. In the sensory test, panelists, who are familiar with the products under evaluation are given a range of samples and asked to rate the samples by choosing a point on a scale ranging from "*dislike extremely"* to "*like extremely"* for different attributes of the products. The general sensory attribute of food products includes taste, flavor, aroma, texture, and appearance. Taste is one of the main attributes for evaluating the sensory quality of vegetable fortified bread since the addition of vegetables has the potential on changing the nutritional bread. We evaluated the sensory attributes and acceptability of the vegetable-fortified bread at 41 locations in Nigeria with 250 panelists per location, for a total of 10,250 panelists. As we have reported, taste preference for the bread decreased as the level of inclusion of vegetables increased in the bread [16]. The results suggest that the vegetable taste could be masked by the sweet taste of sugar but this effect diminishes as the vegetable fortification level increased from 1% to 3%.

Color of food products is one of the important attributes for acceptability of any baked product, especially vegetable-fortified bread. Leafy vegetables are green and this color becomes imparted on the dough as the fortification level is increased in the bread formulations. The intensity of the green color on the vegetable-fortified bread depends on the type of vegetable used (**Figure 4**). In the study by Odunlade et al. [16], vegetable bread-fortified with fluted pumpkin leaf (*Telfaria occidentalis*) was preferred up to the 3% inclusion level, while bread-fortified with 1% *Amaranthus* vegetable was mostly preferred compared with the higher level of inclusions (**Table 3**). This is an indication that the likeness of vegetable-fortified bread also depends on the type of vegetable used.

## **Figure 4.**

*Sensory evaluation on bread with fluted pumpkin leaf slurry.*


*Mean values along the same column with different superscripts are significantly different (*P *< 0.05); WF: heat flour; TOL:* T. occidentalis *leaf powder; AVL:* A. viridis *leaf powder; SML:* S. macrocarpon *leaf powder.*

## **Table 3.**

*Sensory properties of wheat bread fortified with green leafy vegetable powders.*

Studies have shown that consumer acceptance of a product can be enhanced through additional information on potential health benefits or when the actual health benefits have been proven [55, 56]. For the green bread, consumer acceptance improved when potential health benefits, such as antioxidant effects, cardiovascular health, and blood glucose control, were included in the information package.
