Antioxidant Capacity, Microbiological Quality, and Sensory Properties of Yerba Mate-Fortified Yogurt

Abstract

Yogurt is a popular fermented dairy product that has evolved over the years into a variety of styles incorporating different additives to meet the growing consumer demand for natural, healthier, and functional foods. Yerba mate (YM) is a widely consumed beverage rich in bioactive compounds that provide health benefits and may contribute to disease prevention. The objective of this study was to examine the effect of adding YM on the physicochemical, phytochemical, microbiological, and sensory properties of yogurt during storage. Yogurt was fortified with different concentrations of YM freeze-dried extract (0.1, 0.2, 0.3, and 0.4%). Based on the consumer acceptance test, both 0.1% and 0.2% YM-fortified yogurts were considered acceptable; however, the 0.2% formulation was selected for further analysis as it represented the highest acceptable level of YM incorporation. Results showed that yogurt fortified with YM exhibited higher total phenolic content and antioxidant activity compared to the control. Total bacterial counts, total coliforms, yeasts, and molds were not detected in any of the samples. The addition of 0.2% YM enhanced the activity of lactic acid bacteria, resulting in higher bacterial counts, lower pH, and higher titratable acidity compared to the control. Furthermore, YM addition affected sensory attributes, including color, shininess, viscosity, sour aroma, yerba mate aroma, yerba mate flavor, bitter flavor, astringency, bitter aftertaste, yerba mate aftertaste, and astringent aftertaste. Overall, YM represents a promising source of bioactive compounds for the development of yogurt with improved nutritional profile and potential health benefits.