Microbial, Physical and Sensory Properties of Three Novel Yogurt Flavors: Molasses, Mulberry and Amaretto

Abstract

Many consumers incorporate yogurt into their diet as a healthy alternative to other food choices. Providing a variety of flavor choices to the yogurt consumer is important to maintain eating satisfaction. The objective of this study was to evaluate specific attributes of three novel yogurt flavors. These flavors, sweetened with low calorie stevia, include molasses, amaretto and mulberry. Through sensory testing, each flavor was evaluated for consumer product acceptance and purchase intent. Additionally, the yogurt products were assayed for certain physicochemical characteristics and microbial counts. Using a 9-point hedonic scale, fifty-eight participants (23 males and 35 females) evaluated the yogurt flavors for acceptability of appearance, color, flavor, sweetness, sourness, texture and overall liking. Physicochemical characteristics were evaluated for % moisture content, pH value, color (L*, a* and b* values) and lipid oxidation (thiobarbituric acid-reactive substances (TBARS) protocol) every 7 days for 28 days. Through plating techniques, yogurt was assayed for two microbial counts: Escherichia coli and Staphylococcus aureus every 7 days for 28 days. Overall liking scores from the hedonic analysis indicate that mulberry flavor was the most desirable (5.67), followed by amaretto (5.32), and molasses (5.07). From the acceptability, mulberry yogurt scored the highest at 70.69%. From the purchase intent questionnaires, amaretto yogurt scored the highest at 44.83%. In general, there were no outstanding differences in the physiochemical characteristics among the three yogurts tested. However, % moisture content and L* values (lightness) increased in all samples over the 28 days of storage. The TBARS values were higher in molasses flavor at 5.84 mg MDA/kg. No E. coli or S. aureus were detected. This study provides valuable insight into the quality, safety, shelf-life and consumer acceptance of the three novel yogurt flavors.