Effect of Pretreatment Methods on the Sensory and Nutritional Properties of a Yoghurt-Like Product Made from Tiger Nuts (Cyperus esculentus L.)

Under-exploited local plant resources such as tiger nuts (Cyperus esculentus L.) have significant nutritional potential to help consumers boost their immune systems and combat nutritional deficiencies. Tiger nuts can be used to produce a less expensive plant-based yoghurt that would enable people suffering from lactose intolerance to enjoy its benefits. This study aimed to evaluate the sensory acceptability and nutrition-al properties of a yoghurt-like product made with tiger nuts pre-treated by various methods (soaking, drying, roasting, boiling, germination). Nutritional analyses were carried out using conventional methods. Quantifying bioactive and antinutrient com-pounds (tannins, phytates, oxalates and saponins) were conducted via spectropho-tometry and titration methods. A subjective sensory analysis and the organoleptic characteristics was carried out. Yoghurt samples made with tiger nuts, pretreated through roasting (RYS) showed the best sensory characteristics and overall acceptabil-ity. Drying of tiger nuts resulted in a significantly higher energy value, as did the pro-tein content (5.46%) in the germinated yoghurt and the fibre content (2.80%) in the boiled yoghurt. With regard to bioactive compounds, phenolic compounds (393.39mgEAG/100gMS) were more abondant in the yoghurt whose seeds were boiled while the content of alkaloids; (1178.08 mgEC/100gMS) were higher in the products made with roasted tiger nuts. Drying, boiling, roasting and germination were respec-tively the most effective pretreatment methods for the reduction of the amount of tan-nins, oxalate, phytate and saponin. Making yoghurt with roasting tiger nuts appear to be the best option as regards to its sensory attributes and its nutritional properties. The consumption of that yoghurt will be of great importance specifically for those suffering from lactose intolerance.