Effects of cell wall degradation on the polyphenol content and profile of red berries during juice production (eBook)

The quality of red juices is strongly determined by their content of anthocyanins since these are responsible for the nutritional value and organoleptic properties. The final anthocyanin concentration greatly depends on juice production and, more specifically, on the disintegration of the pectic substances in the cell walls during maceration which increases anthocyanin extractability. This work evaluates the potential of ultrasound treatment during enzymatic maceration to enhance pectin degradation. The application of this technique allows for gentle processing conditions regarding temperature and time compared to the conventional enzymatic treatment. Concurrently, the arising pool of soluble pectic oligosaccharides and polysaccharides can be increased which beneficially affects anthocyanin stability by complexation. The resulting interactions are multifaceted depending on the structural properties of both involved compounds. This thesis expands the knowledge of the molecular mechanisms of pectin degradation leading to soluble polymers that increase the stability of anthocyanins by complexation.