Abstract
The used of food-grade photosensitisers for controlling microorganisms promised to be a viable and sustainable alternative strategy to the conventional methods which are complex and operationally, chemically and energy intensive, thereby making them expensive. Also, the quest/preference by food consumers for green technology especially in food disinfection and sanitation is making use of food-grade photosensitisers as suitable alternative for the control of microorganisms. Food-grade photosensitisers/dye extract from non-staple plants could be used for photodynamic sanitation of foods and contact surfaces and treatment of localised topical wound and skin diseases. There are many types of food-grade photosensitisers and dye extracts that can be sourced abundantly from non-staple plant extracts that have got long history of safe use as medicines and foods by humans. These photosensitisers of plant origin are diverse groups of compounds including curcumoids, alkaloids, anthraquinones, perylenequinones, flavins, chlorins, thiophenes, carotenoids, terpenes, and anthocyanins. This chapter discusses basics and targets of photodynamic inactivation in microorganisms. It also discussed and outlined food-grade photosensitisers from plant sources and their photodynamic antimicrobial activity. The chapter concludes by discussing the new thinking/perspectives, challenges and prospects of using food-grade dye extracts for disinfection of foods and contact surfaces.