Great diversity among commercial inactive dry-yeast based products

Abstract

Commercial inactive dry-yeast based (IDYB) products have been shown to impact positively in different ways on the winemaking process, including sensory enhancement. Despite their relevance little information about physicochemical characteristics of individual IDYB products is available. This study aimed to physicochemically characterize a group of ten commercial IDYB products. Organic, protein and carbohydrate contents by spectrophotometric methods, protein diffusion on cellulose membranes and electrophoretic protein profiles were assessed. Interaction of a IDYB product (CP10) with either salivary protein or a proanthocyanidin-rich extract (binary mixtures) or with both of them (ternary mixtures) was also assessed. Marked physicochemical differences were observed among all ten products. CP10 was found to interact with seed extract and salivary protein. Also, as part of CP10-SE complexes, CP10 interacted with the salivary protein to form ternary complexes. Due to their huge diversity, physicochemical characterization of IDYB products before use in winemaking is recommended.