Food by-products play a crucial role in the circular economy. With minor or secondary products obtained in the production process of the main products, the by-products acquire a new value in terms of reuse and recycling to reduce waste to a minimum. The waste or by-products of the agri-food chain can be considered genuine raw materials destined for other sectors, such as energy production, animal feed or natural fertilizers, in a closed cycle, where the waste becomes a resource and nothing is thrown away. This is precisely the concept of the circular economy, which is the basis of sustainability.
Among the main by-products of the food industry are those of animal origin, derived from zootechnics and processing of meat and milk, those of the sugar beet industry, with pulp and molasses, or by-products of the milling and brewing industry, such as starches, bran and fibre; or those of the oil industry, including flour, pomace and biomass and by-products of the wine-making industry for biogas and biomethane plants. The qualities of the by-products can be nutritional, enhanced by the feed, or chemical, used in cosmetics and pharmaceuticals, or energetic, thanks to the production of biogas and biomass, and agronomic through the production of fertilizers. The task of the industry is the maximum exploitation of these food by-products, avoiding their disposal in landfills as waste.
The feed industry has always been one of the leading actors of the circular economy, including by-products of other food production, which can reach up to 50% of the total composition of the feed. One example is the use of wheat bran from mills for flour production. By the way, we are also talking about ex-food products, which, however, are not by-products, but former foods that are no longer suitable for human consumption, because they have expired or with defects but still have a significant nutritional value. For this reason, they are downgraded to ingredients useful in formulating feed for animals. This is a new effective circular economy strategy to reduce waste and CO2 emissions and increase efficiency.
In this regard, the meat production chains are the most virtuous, firmly integrated with many other economic systems, both at the level of farms and industrial processing, with an extensive production of by-products. Just think of the cattle slaughtering industry, from which animal by-products are derived, which can also be used in different sectors. For example, by-products such as leather, wool or some parts of cattle that are used for medical or cosmetic applications, such as soaps and make-up, come from farms. Animal tissues are used in the preparation of medical devices, such as heart valves, pharmaceutical capsules: or in pet food, or for gelatine for food use, for the production of leather and rennet used in the dairy industry.
Waste and by-products can also be converted into compost and fertilizers or energy recovery, as in the case of fats that can be transformed, for example, into biodiesel. Pruning, maize or wheat stubble, rice husk, almond husk, dry foliage and all agricultural residues and by-products may constitute the vegetable biomass from which to obtain soil improvers such as charcoal biochar.
In the marine fishing sector, the by-products of fish processing for human consumption are used for producing fishmeal and fish oils. And also tomato peels, corn leaves, non-compliant seeds, fruit kernels, core and citrus paste: the keyword is “regenerate“, or give the by-products new life for the common goal of zero waste. Sustainable development also starts from here.
