Kendall`s concordance analysis of sensory descriptors influencing consumer preference for sweet potatoes in Ghana

Abstract

Sweet potato is an important crop in the Upper East Region of Ghana due to its adaptive ability on poor quality soils. It is a predominant snack and lunch for children during the peak harvest period, around October-February. This study assessed the influence of some sensory descriptors, with emphasis on the emerging influence of colour, on consumer taste preference. Boiled and fried samples of 7 cultivars were assessed by 57 taste panelists using a five-point hedonic score for taste, colour, flavour, texture, mouth-feel and overall acceptability. A further questionnaire on consumers` first-choice preference and reasons for preference was administered. Kendall`s concordance analysis was performed to test the null hypothesis of independence between variables. Critical descriptors influencing consumer preference were orange-flesh (20.8%), mild flavour (20.8%), soft texture (20.8%) and hard texture (16.7%). Up to 24.1 and and 21.8% of data variation when boiled and 24.2 and 28.5% when fried were associated with sweetness and soft texture, respectively. Cinkase-Abiaga showed distinct orange-fleshed colour score (3.9) followed by Cinkanse-Naabug (3.3) whiles the other varieties recorded a near white colour (1.3-1.4). Overall scores for preference(%) were Purupuru (12.8), Obare-red (15.8), Obare-white (10.5), Kuffour (8.8), Cinkanse (12.3), Cinkanse-Abiaga (31.6) and Cinkanse-Naabug (8.8). Kendall`s concordance coefficients showed this order of preference: Cinkanse-Abiaga (5.9), Purupuru (4.74), Kuffour (4.68), Obare-white (4.6), Obare-red (4.2), Cinkanse-Naabug (2.5). Sensory descriptors of the most preferred varieties (Cinkanse-Abiaga and Purupuru) were starchy-soft texture requiring little chewing, strong flavour and good mouth-feel. Thus, orange-fleshed cultivars which combine these attributes would be appealing to consumers of wide diversities