Publisher Summary This chapter focuses on melezitose and turanose. The establishment of the structure of turanose furnishes a firm basis for an eventual determination of the structure of melezitose. There exist two enzymes that can hydrolyze sucrose; they are referred to as “α-D-glucosidase” and “β-D-fructofuranosidase.” Some yeast extracts contain both enzymes and in consequence liberate the α-D-glucopyranose units from the melezitose molecule and thereby cause total hydrolysis. The usual purified invertase solutions from yeast contain no α-D-glucosidase, which disappears during the processes of purification, and have an ability to hydrolyze sucrose to their content of β-D-fructofuranosidase. Most of the values reported for the specific rotation of melezitose lie between [α]D +88.1° and +88.8°.