Food loss and waste constitute a substantial threat to global food system sustainability, representing 38% of energy consumption in the supply chain. The 2030 Agenda for Sustainable Development highlights a vision integrating social, economic, and environmental pillars. Addressing environmental impact requires recycling (destruction for new creations) and upcycling (converting waste into valuable products). This review highlights nonthermal green extractions and sustainable techniques in upcycling raw materials such as olives, red beetroot, sugar beet, and coffee, which are widely used in the food industry. Nonthermal processing efficiently extracts bioactive compounds and utilizes waste. Key approaches for its valorization include life cycle assessment, environmental footprint analysis, energy efficiency strategies, digitalization, and sustainability considerations. However, challenges remain in calculating their environmental impact. Waste and by-product valorization from raw materials address disposal issues, offering economic and environmental benefits. Nonthermal techniques show optimistic opportunities in green extraction and sustainable upcycling. The focus is on raw materials including olives, red beetroot, sugar beet, and coffee byproducts, and possible product development. There are powerful connections offering industry tools for impactful sustainability management and guiding decisions on waste-to-value or ‘upcycling’ products. The review contributes to filling the gap in usage of nonthermal processing in upcycling of waste and by-products.

The aim of this research was to evaluate the health safety (concentrations of pesticide residues and heavy metals) and nutritional parameters (macro- and microminerals and crude fibre) of coffee silver skin (CS), as well to isolate proteins from this by-product using an optimised microwave extraction method. The CS by-product samples showed the highest amount of potassium, followed by calcium, magnesium, and sodium. Iron was found in the highest quantity among the microminerals, followed by copper, manganese, zinc, and chromium. The CS sample showed a large amount of fibre and a moderate quantity of proteins obtained by the optimised microwave extraction method. Four heavy metals (nickel, lead, arsenic, and cadmium) were detected, and all were under the permitted levels. Among the 265 analysed pesticides, only three showed small quantity. The results for the proteins extracted by microwave showed that the total protein concentration values ranged from 0.52 ± 0.01 mg/L to 0.77 ± 0.07 mg/L. The highest value of the concentration of total proteins (0.77 ± 0.07 mg/L) was found in the sample treated for 9 min, using a power of 200 W. Based on these results, it can be concluded that CS is a healthy and nutritionally rich nutraceutical that could be used in the production of new products in the food industry and other industries.

The Sustainable Development Goals (SDG) encourage the efficient use of sustainable technologies. Ultrasound-assisted extraction (UAE) is one of the extraction process techniques, which are also directed towards sustainability as a goal. Coffee silver skin (CS), being a healthy raw material as well as a waste, could be utilized in the manufacturing process of new dietary products. The goal of this research was to isolate proteins and polyphenols from CS using UAE and to employ spectrophotometry to determine the yields. Three parts of the research were conducted: ultrasonic extraction, the optimization of UAE conditions for the isolation of proteins and polyphenols from CS, and the analysis of the amino acid extract obtained with the optimal use of UAE. According to the results, it was reported that the highest yields of total polyphenols isolated from the CS using UAE were obtained by applying an amplitude of 75% and a time interval of 9 min. The optimal parameters of UAE, when considering the proportions of total polyphenols and proteins, are an amplitude of 100% and a time of 9 min. The most abundant amino acids in isolated proteins (Asp, Glu, Pro, Gly, and Ala) were defined as well. Based on the use of energy, it was obvious that UAE is a promising technology. This concurs with the proposed practice that when non-thermal technologies are analyzed from an environmental point of view, the first common denominator is the use of electricity to run the equipment, in relation to resource depletion. As expected, CS poses a great waste to be recycled, being a nutritionally rich raw material with great potential. Quantitative consideration on the environmentally friendly applicability of CS in mass production should be carried out to validate the entire process of developing a new product from both economic and environmental aspects.