UPCYCLING AGRO INDUSTRIAL BYPRODUCTS TO DEVELOP THE NEXT GENERATION OF FOOD COLORANTS DERIVED FROM NATURE.

The long-term goal of the proposed research is to develop a novel class of food colorants with increased versatility by transforming waste streams into value added ingredients. In doing so, we hope to contribute to improved environmental sustainability, accessibility, and application options for naturally derived food colorants. These colorants will be produced by transforming the natural plant pigments, anthocyanins, using a reaction that naturally occurs in wine, a condensation reaction, to form the more stable pyranoanthocyanins (PACN).The supporting objectives and the hypotheses of the proposed projects are:1. Optimize PACN formation processes by identifying the best reactants and environmental conditions. We hypothesize that certain combinations of ACNs and cofactors will result in faster PACN production and higher yields, especially those that facilitate interaction between reactants (particularly elevated temperatures and agitation). The solution pH will increase abundance of the more reactive ACN and cofactor forms, although the optimal pH will differ depending on starting reactants. Based on our preliminary data, we also hypothesize that decarboxylated cinnamic acids will be more efficient cofactors than their precursor acids.2. Characterize the color, stability, and solubility of PACNs by focusing on the influence of PACN chemical structure and its impact on behavior in food matrices. We hypothesize that each PACN will produce a unique set of colors across pH values, and their unique structures will give different levels of solubility and compatibility in food applications. We believe that PACNs with less sugars and more aromatic rings will have lower solubility in water and may interact better with matrices containing lipids or proteins while precipitating in water. On the contrary, PACNs with more sugars and hydroxyl groups will remain more soluble in water, making them more suitable for water-based matrices. We also predict that PACNs will be able to provide color for a much wider range of pH values (1-9) than their precursor ACNs, and therefore, be better options for coloring a wider range of food applications.3. Develop a novel production process for PACN-based food colorant production by upcycling agro-industrial byproducts using lactic acid bacteria and biotechnology. We hypothesize that insoluble plant residues obtained from agro-industrial processes will contain phenolics trapped in macromolecules that could be released through hydrolysis and fermentation to become the cofactors for PACN formation. Waste streams from colorant production will contain both residual ACNs and the cofactors to use for PACN formation. We hypothesize that a bioreactor can be used to favor the transformations and interactions to produce PACNs from waste streams.