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.

Thermal characteristics of dried sugar beet pulp, leaves and leaf fractions obtained after extraction: fibrous leaf pulp and fibre rich leaf fraction, were investigated by differential scanning calorimetry and thermogravimetry. The sugar beet samples showed a similar thermal behaviour associated with a similar composition. Two endotherms are found on the differential scanning calorimetry curves. First one in the temperature range 31–153 °C and the second from 150–160 °C. Thermal degradation kinetics was studied by thermogravimetric analysis. Four degradation stages were observed within the temperature range 25–700 °C. The kinetic parameters of the degradation, obtained by Ortega and Friedman non-isothermal isoconversional methods did not significantly differ between models: Ea-activation energy at a conversion degree 0.1–0.9 ranged 50–200 kJ/mol; lnA- the natural logarithm of the pre-exponential factor 8–48; kp₁-thermal degradation rate constant at a conversion extent of 0.5 ranged of 0.19–2.55 min⁻¹. Constant rate of degradation is highest for the sugar beet leaves kp₁ (2.58–2.55 min⁻¹), and kp₂ (70.1–70.4 min⁻¹). The results obtained are valuable for sugar beet leaf industrial processing. A positive environmental impact is achieved by transforming the waste into high-value food additives.

Ultrasound-assisted extraction (UAE) using water as a green solvent is a promising non-thermal technique for the extraction of total dietary fiber (TDF) and betaine from red beetroot (Beta vulgaris L.) peel. Compared to conventional thermal extraction (CE), UAE has proven to be a more efficient alternative method for the extraction of TDF and betaine. The pretreatment of beet was carried out using pulsed electric field (PEF) technology, with the specific energy of the PEF treatment set at 1.6 kJ/kg. To achieve the maximum betaine concentration of 24.80 µg/mL, the optimum UAE parameters were 50% amplitude with an extraction time of 3 min using distilled water as extraction solvent. The optimum TDF yield of 44.07% was achieved at 75% amplitude, 6 min treatment time and 50% ethanol solution as extraction solvent. These conditions can effectively supplement UAE, especially in the extraction of bioactive compounds from red beetroot peel. However, the TDF obtained in the residue must be evaporated for further use, which increases energy consumption. Ethanol concentration had no statistically significant effect (p > 0.05) on the TDF results, suggesting that distilled water could replace ethanol as a solvent in UAE. This substitution offers environmental and economic advantages, as water is more environmentally friendly and less expensive than ethanol. In addition, the use of distilled water eliminates the need to evaporate ethanol, which is particularly advantageous when the extracted material is intended for fortification or improvement of the technological and functional properties of food products.