The utilisation of microbial poly-hydroxy alkanoates (PHA) in food industry

Abstract

Biodegradability is defined as the capacity of to be broken down by the action of living things, such as bacteria and fungi being the main participants in the process of biodegradation in the natural world. The breakdown of materials provides them with precursors for cell components and energy for energy-requiring processes. Biodegradation is thus defined as catabolism. Some synthetic polymers, having chemical compositions resisting enzymatic attacks, can be microbially degraded with slower processes. Bioplastics is a term used for packaging materials derived from renewable resources and are considered safe to be used in food applications. In comparison to conventional plastics, the monomer composition of bio-based polymers can be differed by varying the producing strains, substrates and cosubstrates, and biopolymers such as polyhydroxyalkanoates (PHA), polylactic acid (PLA), polysaccahrides.

PHAs are carbon-energy storage material accumulated intracellularly in a variety of microorganisms under controlled concentrations. Their biodegradability and possibility to be synthesised from renewable agricultural or even industrial wastes, make PHAs of considerable interest. Their main applications in food industry are serving as waterproof layer for the production of disposable food containers and utensils, cast films and cast sheets for thermoforming and utilisation as good odour and oxygen barriers.