Stability of beverages of yerba mate (Ilex paraguariensis) with soy

Purpose - Forasmuch as the consumer's demand for food products that provide nutrition and health benefits has considerably increased in the past decade, the authors decided to join two important Brazilian commodities in a high-nutrition drink: yerba mate (Ilex paraguariensis) is rich in several bioactive compounds, and soybean is a high-quality protein source. To optimize the design and maximize the acceptability of the beverage, the authors studied its stability during storage. The beverage developed allows enlarging of the potential market of yerba mate, taking profit of the growing call for the consumption of antioxidant foods and benefits small-scale producers. Design/methodology/approach - Twelve beverages were formulated with extract of yerba mate from leaves of planted (P) and native trees (N), both enriched with water-soluble soy extract (WSE). Among all formulations, two of them, which were sensorially preferred in a previous study, were selected to investigate their market potential. During the six months of storage, microbiological analyses were performed and the parameters acidity, viscosity, pH and rutin content were assessed. Sensorial tests of acceptability and purchase intent were also conducted. Findings - The drinks remained microbiologically adequate for consumption during six months of storage. High sensory acceptability and purchase intent scores were obtained for Beverage P. This drink resulted in smoother taste and presented a decrease in acidity and constant viscosity during the storage, while Beverage N had an increase in acidity and viscosity. The rutin loss at 120 days was 14.2 per cent for Drink P and 32.4 per cent for N, with a half-life of 423.6 and 185.3 days, respectively. Originality/value - Given the quantified parameters, the beverage produced from leaves of planted trees (P) may be used as a novel high nutrition food suitable for the growing requirements of the yerba mate by-products market.