ABSTRACT
This chapter provides an overview of the nature of such bacterial associations in yogurts and describes the interactions among the bacteria involved, and detail how bacterial metabolic activities impact the properties of the product. It focuses on traditional yogurts; yogurts or fermented milk products that contain probiotic species, stabilizers, and added aromas. The chapter understands the yogurt microbiology, and especially of the metabolic processes that are essential for yogurt production. Yogurt can also be considered to be a probiotic foodYogurt can also be considered to be a probiotic food. Typically, yogurts are produced at temperatures around 42°C, which promotes the optimal growth of both S. thermophilus and Lb. bulgaricus. When milk is inoculated with the two bacteria, they usually grow in succession and S. thermophilus presents diauxic growth. Some of the first metabolic exchanges described in S. thermophilus and Lb. bulgaricus associations in milk were interactions involving folic acid, pyruvic acid, formic acid.
