Waste Generated by Food Industry and Reuse in A Circular Economy Approach: The Whey Processing

The popularity of the circular economy is due to the increasing amount of waste-produced in the agro-food processing industry; new solution of waste recycling with biotech innovation are available. In the EU 3.5 ton per capita of waste are annually produced, including more than 400kg per person per year of domestic waste. The projections suggest that this increase at worldwide level, will continue at least until 2030 and there is no real evidence of decoupling between waste and economic growth despite progresses in waste recycling. While all sectors are potentially eligible for funding under the Eco-innovation initiative, certain activities have been singled out as priority areas because of their considerable impact on the environment and their potential contribution to meeting the EU’s own environmental objective. In the modern Agro-food system, the proper treatment of organic effluents to avoid their discharge as sewage water or sewage sludge, to prevent the pollution of the ground and water resources (oceans, lakes, rivers) is becoming especially important. Water is essential not only for direct uses, but also for ensuring the integrity of the ecosystems and the goods and services they provide to humans. The case we have considered is the whey, a by product of the cheese production, requiring urgent solutions to improve water efficiency and water quality used in the cycle.


Mini Review
The popularity of the circular economy is due to the increasing amount of waste-produced in the agro-food processing industry; new solution of waste recycling with biotech innovation are available. In the EU 3.5 ton per capita of waste are annually produced, including more than 400kg per person per year of domestic waste. The projections suggest that this increase at worldwide level, will continue at least until 2030 and there is no real evidence of decoupling between waste and economic growth despite progresses in waste recycling. While all sectors are potentially eligible for funding under the Eco-innovation initiative, certain activities have been singled out as priority areas because of their considerable impact on the environment and their potential contribution to meeting the EU's own environmental objective.
In the modern Agro-food system, the proper treatment of organic effluents to avoid their discharge as sewage water or sewage sludge, to prevent the pollution of the ground and water resources (oceans, lakes, rivers) is becoming especially important. Water is essential not only for direct uses, but also for ensuring the integrity of the ecosystems and the goods and services they provide to humans.
The case we have considered is the whey, a by product of the cheese production, requiring urgent solutions to improve water efficiency and water quality used in the cycle.

The Cheese Manufacturing and Whey Processing
Cheese whey (CW) is the liquid part after milk has been curdled and strained in cheese production; it is the main by-product of the cheese making [1] After coagulation casein curd separates from the milk, under the action of chymosin or mineral/organic acid producing; the remain is the whey, a watery and thin liquid solution.
Approximately from ten parts of milk, one part of cheese and nine parts of whey are produced with appreciable quantity of water soluble components [2]. It is estimated that the whey produced annually by the European dairy industry is about 75 million tons.
it is a by-product of cheese making process, in the past it was discharged as waste into soil, rivers, lakes, causing pollution. When and specifically the whey is the interest of many researchers, interested in the dairy chain optimization and sustainability. The whey is a by-product of the cheese production chain; in volume represents the 80-90% of the milk converted into cheese. Sweet skimmed whey is subjected to a concentration step, removing 80% of its water content. A convenient solution is to extract proteins from retentate fraction and sell into separate market outlets. The permeate fraction rich in lactose (45gr/liter) is a carbon source for different metabolic pathways. We concentrate in the lactose fermentation to produce PHA; a number of studies identified many microbial groups able to synthesize these polymers, the most important are the Rastonia group, the Escherichia coli, the Capriovidus Necator. These bacterial species are the most used for industrial application since they associate high productivity and reduced times of PHA accumulation. The PHA accumulation speed is very variable: specific rate 0.15 g/g*h equivalent to 15% yield per hour; 16.8 g/L biomass containing 73% PHA were obtained Koller [3]. In the medical field, PHAs were already investigated as bone implant materials, for tissue engineering, for in-vivo application as implants, surgical pins, screws, meshes and sutures, and as carrier matrices for controlled drug release. Also the production of By the way marketing opportunities for whey proteins and lactose are growing and compete with PHA production. The 2 nd problem is the optimization of the downstream processing for PHA recovery and refining after cell harvest. As intracellular products, PHAs have to be separated from the surrounding non-PHA cell mass, mainly consisting of proteins, lipids, nucleic acids and special polysaccharides. Here, high input with often highly polluting solvents and enormous energy demand still are the caveat in PHA recovery, compromising the demanding claims of these bio-plastics to be ecologically sound materials. The 3 rd problem implies to afford the increasing productivity by designing the optimal engineering plant for the final break-through of these biopolymers on the market. A continuous biotechnological production process is well known as an interesting solution for achieving high productivity, lower costs and constant product quality. Some authors reported high productivities of 1.85g/L h for PHB and a constant and satisfying product quality using Cupriavidus necator strain.

Biodegradability
To optimize the entire PHA chain, we suggest the following steps: a) Optimize the collection whey costs from a basin area of enough size to cover the costs and minimize the environmental cost of transport [4].
b) stabilize the whey quality and improve the efficiency of the whey processing through advanced membrane methods of ultrafiltration, nanofiltration, inverse osmosis.