Abstract #M142

# M142
Influence of the antimicrobial myrrh on yogurt culture bacteria over yogurt shelf life.
M. Alhejaili*1, D. Olson1, M. Janes1, C. Boeneke1, K. Aryana1, 1Louisiana State University Agricultural Center, Baton Rouge, LA.

Myrrh is a natural flavoring substance approved by FDA as a food flavor and essential oil. Also, myrrh has antibacterial and antifungal activity against pathogens. The objective was to determine the effect of myrrh on Streptococcus thermophilus and Lactobacillus bulgaricus counts, pH and titratable acidity of yogurt during 5 wk of storage. Myrrh dispersion was prepared and incorporated at 1% vol/vol yogurt mix. A control with no myrrh was also prepared. Three replications were conducted. Streptococcus thermophilus was enumerated using Streptococcus thermophilus agar with aerobic incubation at 37°C for 24 h, and Lactobacillus bulgaricus was enumerated using MRS agar adjusted to pH 5.2 with anaerobic incubation at 42°C for 72 h. At 5 wk of storage at 4 + 1°C, S. thermophilus counts in yogurt containing myrrh (5.4 log cfu/mL) were not significantly different than S. thermophilus counts in the control yogurt (5.3 log cfu/mL). Although the log counts for L. bulgaricus were significantly lower for the myrrh yogurts than for the control, the counts remained within a log of each other throughout 5 wk of storage. The pH of the yogurts containing myrrh was significantly higher than the control yogurt, but their pH values were within 0.1 pH units of each other at any given week. The titratable acidity values remained steady around 1.2% expressed as lactic acid for both yogurt types throughout the storage period with no significant differences between them. With little to no change in yogurt pH and titratable acidity, yogurt culture bacteria can survive in the presence of myrrh within yogurt.

Key Words: fermented, antimicrobial, yogurt