A little extra value from eggshells
Egg processors produce hazardous waste in the form of eggshells that incurs an annual disposal cost of about EUR 100 000. However, eggshell membranes contain hyaluronic acid and native collagen, which are of considerable value to the cosmetics, pharmaceutical, nutritional industry and plastic surgery. So far, they are relatively expensive, so it is desirable to find new sources of these raw materials. To sell these membranes, the EU-funded 'Separating eggshell and its membrane to turn eggshell waste into valuable source materials' (SHELLBRANE) project worked to separate eggshells and their membranes at industrial scale. SHELLBRANE researchers first conducted a survey covering market needs and the potential buyers of eggshell membrane. The entire process from separation and disinfection to post-processing and mechanical design was then documented to generate specifications for an eggshell processing system. Following this, the project conducted laboratory trials and assessed different mills and crushing equipment. Based on this, physical separation techniques such as flotation, filtration and streaming were selected for separating eggshells from their membranes. Project partners also conducted laboratory trials and microbiological analyses, such as ultraviolet-emitted power and time of disinfection, to optimise the disinfection process. SHELLBRANE then modified and integrated the disinfection and drying units into the prototype. The prototype was compiled and tested both in the lab and on-site at an egg processing plant in Hungary. Extraction trials yielded good concentrations of collagen and hyaluronic acid from membranes separated by the prototype system. Use of egg processors in industrial food processing is likely to increase, with rising consumption of eggs in bakeries, confectionery products, sauces and pastas. The SHELLBRANE system will enable industrial eggshell waste to be profitably processed and resold. Recycling of eggshell waste will help small and medium-sized enterprises profit from waste while avoiding disposal costs, thereby creating more jobs and increasing overall competitiveness.
Keywords
Eggshell, eggshell waste, eggshell membrane, hyaluronic acid, collagen
