Evaluation of microbial and sensory properties of flavored yogurt drink produced by Noaea mucronata and liquid smoke treatment

Liquid smoke is more acceptable compared with traditional smoking for various practical and health reasons. This study aimed to investigate the quality attributes of yogurt drink treated with natural and liquid smoke. Yogurt drink samples were divided into four groups; natural smoked, liquid smoked at two concentrations (1 and 2 mL·L-1) and un-smoked control samples. Microbial and sensory attributes of yogurt drink samples were analyzed after 1, 7, 14, and 21 days of storage at 4°C. The final counts of total bacteria, lactic acid bacteria, yeast and molds were significantly lower after the application of 2 mL·L-1 liquid smoke compared to control samples. Moreover, lactic acid bacteria of yogurt drink were not inhibited by natural smoke or 1 mL·L-1 liquid smoke treatments. According to the sensory evaluation and microbiological analysis, application of 1 mL·L-1 of liquid smoke in yogurt drink is the most appropriate and convenient alternative to the traditional smoking method.