Today, researchers consider food wastes as a source of valuable compounds such as dietary fibers, flavonoids, polyphenols, glucosinolates, anthocyanins, proteins and enzymes. This ambition generated by the fact that the current processing methodologies allow the recovery of target compounds and their re-utilization inside food chain as additives, supplements or food fortification. However, the labelled products derived from food wastes are few compared to the plethora of investigations in the field, patented methodologies and proposed scenarios. So, what are the obstacles of making this trend really happen?
We can find different answers following the most relevant aspects of the applied technologies. For instance, energy efficiency of conventional techniques is not so high and respective cost is not low enough to extract compounds that exist in lower concentrations inside by-products compared to the initial substrate (i.e. whole fruits or vegetables). In addition, traditional thermal processes such as concentration, drum or spray drying may cause enzymatic or non-enzymatic deterioration of the target compounds, loss of their functionality and diminution of the final product’s organoleptic characteristics. In many cases, conventional extraction is restricted due to the non-food grade nature of the used solvents. Target compounds such as antioxidants may not be stable in the shelf due to the inefficient encapsulation of the final product. Besides, consumers are and always will be sceptical about the safety of products derived from by-products or food wastes.
The yield of the applied technologies, the scale up boundaries, the safety of the final products and the overall cost are the most important parameters governing the industrialization of recovery processes. Nowadays, improving process efficiency during food manufacturing focuses on minimised cost. The latest is typically conducted by reducing processing steps, enhancing throughput, restricting overall energy consumption and optimizing plant design. Emerging and typically non-thermal technologies (e.g. radio-frequency drying, electro-osmotic dewatering, cold plasma treatment, high-hydrostatic pressure, ultrasound-assisted extraction, laser ablation, high voltage electrical discharge, pulsed electric field, nanoencapsulation, etc) promise to overcome the obstacles of conventional techniques by claiming increased recovery yield and reduced processing time, optimized heat and mass transfer that results in lower operation cost, gentle treatment of food waste matrix and control of unwanted Maillard by-products, advanced encapsulation and ultimately improved functionality of antioxidants.
Read the whole article in my Elsevier SciTech Connect Blog: