Defining the Quality of Commercial Ghanaian-Produced Stirred Yoghurt

Abstract

The dairy product industry is steadily growing on the Ghanaian market with increase in consumption and demand from consumers. Stirred yoghurt is a popular and highly consumed dairy product found on the market and there are different types available, with variability in flavouring, viscosity, colour and taste. To maximize market share, it is important to identify key quality criteria for yoghurt that will satisfy consumers. This study was conducted to identify and define sensory characteristics of commercial stirred yoghurt on the Ghanaian market and determine key attributes that drive consumer acceptance. Fourteen stirred yoghurt samples were selected and assessed by 8 trained sensory panelists to develop a lexicon that describes the yoghurt samples. Acceptance testing was conducted with 61 consumers followed by preference mapping to identify key drivers of liking. Sensory, physicochemical and microbiological quality indices were monitored over time to determine quality of selected stirred yoghurt samples on the market. The yoghurt samples were differentiated by twenty-one descriptive attributes (p≤ 0.05). Hierarchical clustering of the preference data identified three homogenous consumer clusters for yoghurt. Results from preference mapping showed that glossy appearance, yoghurt-like aroma, sour flavor and afterfeel, and an astringent afterfeel were the key drivers of consumer liking for commercial stirred yoghurt. There were significant differences (p≤ 0.05) in pH, % lactic acid, colour, and microbiological indicators of the yoghurt samples. Quality indices monitored over a period of 7 weeks showed inconsistency in the quality of the yoghurt samples evaluated.