Pectins form the middle lamella and are matrix compounds in the primary cell wall where they assemble into a cellulose hemicellulose network. Pectic polysaccharides are among the most complex polymers in nature. Homogalacturonans, rhamnogalacturonans I, and rhamnogalacturonans II are groups, into which pectic polysaccharides are often divided. In addition, other substituted galacturonans such as xylogalacturonans were described in the past. However, an enormous structural variety exists within these groups. This is true for major structural units such as arabinan/(arabino)galactan ratios in rhamnogalacturonans I, but also branching of these polymers and incorporation of less usual monomers into pectic polysaccharides. The molecular assembly of pectic polysaccharides and functions of individual structural units are far from being understood. Pectin structural characteristics affect pectin functions in the plant and may also affect their functionalities in food products and their enzymatic degradability. The impact of homogalacturonan structures on their use of gelling agents in food products is well accepted; however, very little is known about rhamnogalacturonan functionalities in food products and their potential health benefits as part of the dietary fiber complex. Our current research on pectins is focused on the characterization of structural units in pectic polysaccharides and the development of profiling methods to analyze the structural features in pectins from different sources. In addition, we strive to understand how these fines structures affect pectin functionality.