Effect of Incorporating <i>Parkia Biglobosa</i> Pulp on the Sensory Characteristics of Stirred Yoghurt

Parkia biglobosa, called African locust bean in English, is a non-wood forest product that provides a pulp with good nutritional qualities. Consumed in its raw state, the pulp is generally not processed in any way. With this in mind, the pulp was incorporated into yoghurt at levels of 2%, 4%, 6%, and 10% (note that a control yoghurt without pulp was prepared). A hedonic test was also carried out on a panel of 63 people to assess the acceptability of the yogurts designed on a rating scale of 1 to 9. Interpretation based on the average of sensory attributes (colour, smell, appearance, texture and taste) showed that yogurts Y1 (0% pulp), Y3 (4% pulp) and Y4 (6% pulp) were better than yogurts Y2 (2% pulp) and Y5 (10% pulp). In order to optimise the processing of sensory data, the validity of the one-factor ANOVA was studied. The study revealed that the ANOVA was invalid and that a non-parametric test (Kruskal-Wallis) enabled the sensory data to be processed correctly. The Kruskal-Wallis test showed that no significant difference was detected in terms of appearance, texture, and taste between yoghurt Y1 and yoghurt Y3. However, there was a significant difference in colour and odour between Y1 and Y3, even though the panellists found Y3 pleasant in terms of colour and odour. Statistical analysis, principal component analysis (PCA), and the hedonic profile established on the basis of this experiment indicate that the incorporation rate of 4% African locust bean pulp represents the ideal rate since the appreciability of the organoleptic criteria of Y1 is almost similar to that of Y3.