Food waste valorisation: new horizons for a more sustainable society

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The processing of agro-food has increased considerably during the last 25 years mainly on account of feeding the rising population. The result is the simultaneous generation of food processing wastes.  A statistical study done by Baiano [1] reveals that about 26% of food wastes are generated from the drinks industry, followed by the dairy industry (21%), fruit/vegetable production and processing (14.8%), cereal processing and manufacturing (12.9%), meat product processing and preservation (8%), manufacturing and processing of vegetable and animal oils (3.9%) fish product processing and preservation (0.4%) and others (12.7%). Such food wastes are diverted to landfills and their improper disposal result in environmental problems like toxicity to aquatic life, pollution of surface and ground waters, altered soil quality, phyto-toxicity, coloured natural waters and odour.

Valorisation in other words, a complete conversion of such food wastes into marketable products and energy so as to obtain a zero waste society is an alternative and more sustainable way to live in. Sustainable development has become a priority ever since the impact of humanity on the environment has been greatly accelerated with rapidly rising population and the simultaneous sharp decrease of the natural resources.  In this respect, some of the mature technologies that have fast gained into prominence are the anaerobic digestion, fermentation and composting. Such bio-technological advances involving microorganisms are involved in the breakdown of complex food wastes to bio-fuels, biomass, bio-fertilisers and secondary chemicals. Another strategy is related to the use of pyrolysis of the food wastes in the synthesis of biofuels and syngas. This involves heating of the biomass at high temperatures in the absence of oxygen to produce decomposed products like the Bio-Oil and syngas. More recently, the use of microwave in conjunction with pyrolysis has been proposed as a low temperature pyrolysis protocol for the synthesis of Bio-Oil and syngas from various food wastes. Besides the energy production, pyrolysis has been used to convert food wastes to biochars and advanced materials like carbon nanotube and graphene-like materials. Such materials have a wide range of applications including soil and water remediation. Recovery of high value added components and their reutisation as food additives, cosmetics, therapeutics etc. is another strategy used under the waste valorisation concept. The value added components like polyphenols, succinic acid, furfurals, bioplastics, oils etc. are selectively extracted from the food matrix through a combination of bio-chemical, chemical or enzymatic approaches followed by their modification into higher value food products or additives.

Research activities under the Marie Curie funded ¨VALOWASTE¨ project hosted at IRIS are centred on maximising the yield of such bio-products via the optimisation of the underlying technologies, on the final use of the bio-refinery products and finally on the economic viability of the process. (Blog post: Marie Curie funded VALOWASTE: Relevance to agrofood industries, environment and society). The overall valorisation concept for the management of food wastes has a positive impact to the environment due to less greenhouse gas emissions, reduction in the environmental burden of their disposal and lesser dependence on fossil based sources for fuel generation.

  1. Baiano, A. Recovery of Bio-molecules from Food Wastes -A Review. Molecules, 19, 14821-14842 (2014)

 

PhD Arunima Nayak
Marie Curie Researcher
PhD in Environmental Chemistry

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